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FAQs about Overflows, Bulkheads/Through-puts, Holes vs. Boxes... Troubleshooting & Repair

Related Articles: Overflow Box Arrangements, Plumbing Marine Systems by Bob Fenner, Myth of the One Inch Beast (Why Relying on One Inch Overflows... or Overflow! Is foolhardy) by Scott Vallembois, The Flowrates through various Bulkheads (In relation to overflow drains) by Scott Vallembois, Plumbing Return Manifolds, Refugiums

Related FAQs: Overflows 1, Overflows 2, Overflows 3, Overflows 4, & FAQs on: Pump/Plumbing Noise 1, Pump/Plumbing Noise 2, & FAQs on: Rationale/Use, Sizing, Through-Hull Fittings, Hang-On Selection, Plumbing... Marine Plumbing 1, Marine Plumbing 2, Marine Plumbing 3Marine Plumbing 4, Marine Plumbing 5, Marine Plumbing 6, Plumbing 7, Plumbing 8, Plumbing 9, Plumbing 10, Plumbing 11, Plumbing 12, Plumbing 13, Plumbing 14, Plumbing 15, Plumbing 16, Plumbing 17, Plumbing 18, Holes & Drilling, Durso Standpipes, Make Up Water Systems, Pumps, Plumbing, Circulation, Sumps, RefugiumsMarine Circulation 2, Gear Selection for Circulation, Pump Problems Fish-Only Marine Set-ups, Fish-Only Marine Systems 2, FOWLR/Fish and Invertebrate Systems, Reef Systems, Coldwater Systems, Small Systems, Large SystemsWater Changes Surge Devices

Define: "reef ready" Palauastrea ramosa

sealing a bulkhead, no sump necessary. & Fig. 8 puffer stkg./sel.   12/6/11
Dear Crew,
Greetings and happy holidays!  I've been searching the site for the last couple of hours, but couldn't find anything related to my particular query.
 I have a 40 gallon breeder that I had planned to use as a reef tank, but am now looking at doing brackish or planted setup instead.  The tank is drilled in the bottom panel, in the rear-left corner, but I don't really need to utilize a sump as I'm planning on two Hagen AquaClear's for filtration.  It's been water tested over the last few days using only a ball valve to stop it from draining, but I was looking for more of a long term solution to sealing this unnecessary hole.  Any thoughts?
<Can you not simply seal off this/any drainage holes in the tank, e.g., with small bits of glass and aquarium-grade silicone? Silicone is nice because you can cut it away if needs be, freeing up the holes should you need them down the road.>
Also, in looking into the brackish system, I have developed an interest in Figure 8 puffers, but have read conflicting information re temperament, compatibility, and minimum tank sizes.  If keeping these and bumble bee gobies, how many would be recommended without overloading my tank and causing aggression issues.
<Figure-8s are generally easy to keep. As a base-line stocking density, allow 20 gallons for the first specimen, then another 10 gallons per additional specimen. With good water quality you might be able to keep one or two more. A low salinity is fine, so plants are an option, e.g., SG 1.002-1.003, with appropriate salt-tolerant plants like Vallisneria, hardy Crypts, some of the Crinum species, and so on. They do work well with Bumblebees, but these gobies are fussy feeders, so research that aspect carefully. Figure-8s are territorial but not especially aggressive. They are fin-nippers though, so cannot really be recommended for community tanks. That said, some folks have kept them with pushy, fast-moving tankmates like Orange Chromides, Monos and Scats.>
Thanks for all of the resources you provide,
<You're welcome, Neale.>

Slow flowing overflow   7/2/10
Hey guys. I just recently decided to start a sump filtration system on my 55gallon tank not drilled. I bought a over flow box for the tank a sump and return. The return is excellent but my issue is that no matter how much I try I'm getting a very slow rate to no flow at all into my overflow. I made sure there is no blockages or anything. Please help me out. I have done a lot of reading and used a lot of the advice you have given to other. All your advice is appreciated. Thanks
<Hmmm, some more information is needed here. By not getting into your overflow, you mean it is not transferring from the front of the box to the back where it can drain down? I take it this means when you turn your return pump on the tank starts to overflow. Which overflow box and return pump are you using? Scott V.>

Acrylic Aquarium Crazing Repair (And Bulkhead Installation) -- 06/10/10
<<Howdy Jake>>
I have recently purchased a used 120 gallon Sea Clear acrylic aquarium 24 inches tall, 60 long and 18 deep constructed of 3/8 inch panels.
<<Mmm, be aware you may experience some slight bowing of these panels at this tank height. Nothing that should cause any problems structurally, but ½' material would have been better here>>
After taking it apart for transport and then reattaching the bulkheads (which are on the bottom of the tank) it was leaking at the seals of the bulkheads. So I then replaced all the rubber seals and it still leaked. Well then I used a wrench to tighten the bulk heads and I plugged the bulkheads that were leaking. One of the bulkheads was still leaking and to make matters worse it looks like I over tightened the bulkheads and now I can see crazing radiating out from the bulkheads about 2 inches.
<<Yep'¦too much 'oomph' with the wrench>>
I cannot feel any of the cracks from the surface and they appear to be within the acrylic panel. If you look at it from the side you can see the crazing is just below the inferior and superior surface of the panel and is less than 1/16 of an inch. So can this tank be fixed and any tips on getting bulk heads sealed?
<<I think so'¦and yes>>
I read through your website and was thinking that maybe using Weld-on and putting an acrylic patch over the crazed areas may be good enough.
<<Is one option'¦ Make the patches about 2' larger than the crazing, and use material of the same thickness as the bottom panel. A better option would be to fit and solvent weld a whole new bottom panel atop the existing bottom panel. Make sure you clean up the bottom interior and apply any patches from the 'inside' only, as acrylic tanks require support along the entire surface of the bottom of the tank and any patches applied to the exterior will obviously be a problem re. Whichever method you use, I suggest you drill new throughputs in a different location and don't try to reuse the existing compromised holes. You might also want to consider moving the location of the bulkheads from the bottom to a side or back panel. As for 'seating' the bulkheads themselves'¦ First, I place the washer so it will be on the wet-side of the bulkhead, then I run a heavy bead of silicone sealant around the edge of the hole on the outside. Insert the bulkhead from within and hand-tighten the nut on the outside then give it about a quarter turn with a wrench to snug it up. Let the silicone cure before adding water to the system (overnight or longer) and you shouldn't have any problems with 'leaky bulkheads.' The silicone forms a flexible yet solid seal that is still easy enough to break free should you ever need to remove the bulkhead>>
However this tank was cheap and I really don't want 120 gallons of water on my floor.
Thanks for your time and you have a great web site, Jake
<<Happy to share'¦ Eric Russell>> 

Overflow troubles   5/25/10
Hi crew,
I would like to ask some advice. I have a 150 gallon with two corner overflows/returns. My pump is a Mag drive 9.5. I have an elbow with a hole drilled toward the bottom and an air pipe sticking out the top of the elbow
for the air. I am having trouble equalizing the overflow. The overflows flow ok, then only one side drops down past the air hole then raises back up again.
<If these are the common 1" lines they will possibly keep up with this pump once plumbing and head loss are accounted for, but will not leave you any safety margin. See: http://www.wetwebmedia.com/BulkheadFloRateArt.htm>
My tank is not exact level and goes down on this side, making the water drain in slightly before the other side. Would this have an affect on this?
<Yes, water flows downhill! So it will work one line harder than the other.>
Would making the pipe on this side taller/shorter help?
<Not if it is within a box. The tank really needs to be leveled, there are other (possibly catastrophic) consequences. See: http://www.wetwebmedia.com/aqstands.htm>
They drain into two Tidepool sumps. Which then I am getting a lot of tiny bubbles pumped back into the main tank. Would this be due to the dropping of the water in the overflow or something with the pump?
<The water and air in the line. There is not much to get around this, it is the way an overflow works. You will have to handle the bubbles in the sump. Read through the bubble FAQs for some ideas here.
http://www.wetwebmedia.com/bubtroubfaqs.htm One or both of your overflows sound like they are siphoning. You will need to level the tank and then either go with larger drains or less flow.>
Any advice would help, I am stumped. Thanks
<Welcome, Scott V.>

Surface Skimming Problem 1/5/10
Happy New Year to you all,
<Thank you from the crew and may you also.>
I say this every time I write, I know, but I love this site, and I appreciate all your knowledge, experience and willingness to share.
<We thank you for this.>
I need a bit of advice. I have a 90 gallon AGA soft coral reef with just a few fish. The internal corner overflow is not skimming the surface of the water. The water rises a bit above the cut out slits. This problem started when I upgraded to an Eheim 1262. I have one 1 3/4 inch Durso standpipe. The water level in the tank does not change when I block the standpipe vent. Do you think I should modify the slits? Perhaps use a Dremel tool to widen every other slit or just cut off a section and cover it with plastic gutter guards? Any advice would be appreciated.
<Victoria, there is no PVC pipe size that is labeled 1 3/4" pipe. A 1 3/4" inside diameter would be close to a 1 1/2" PVC pipe. Which do you have, and what is the size of your bulkhead fitting? I'm thinking your new Eheim (900gph) is putting out slightly more gph than your bulkhead fitting can pass which leads me to believe your bulkhead fitting is 1 1/2". With no other restrictions in the drain line such as elbows, valves, tees, and/or the use of ribbed hose, a 1 1/2" bulkhead can pass approximately 975 gallons per hour. With a few restrictions added, this can drop significantly. I don't believe making the slits wider is going to help you much as long as the square area of all the slits is equal to or greater than the inside area of a 1 1/2" pipe. A good test would be to remove the slitted standpipe if it is not glued to the bulkhead fitting and see if the water level drops inside the overflow.>
Thank you for your time,
<You're welcome. James (Salty Dog)>
Re Surface Skimming Problem 1/5/10
Thanks for the speedy reply.
<You're welcome.>
You stopped me just in the nick of time. I had the Dremel tool in hand, ready to go. Just kidding. I could not remove the entire standpipe as it is a threaded fitting, and bad things have happened in the past when I removed that standpipe.
<Oh yes!>
I did remove the Durso fitting, as it is a slip fitting, and the water inside the overflow section dropped to the top of the standpipe, and the lovely slurping began. The level of the water in the display dropped only a hair, but stayed well above the overflow slits. So does this mean the bulk head is not restricting the flow? What should I do now? I do have my Dremel tool in hand.
<Sounds like you are trigger happy with that Dremel (Ha). Is the small vent hole in the Durso plugged up with calcium/debris? If so, try cleaning up the hole and if that renders no help, try increasing the vent hole size slightly and see if that lowers your water in the overflow.. If none of these suggestions help, do send pics of your Durso and the front of the overflow weir so I can get an idea of what you actually have.>
Thank you for your time,
<You're welcome. James (Salty Dog)

Micro Bubbles -- 10/31/09
I recently (within the last week) moved my sump/refugium to the basement.
It makes things so much easier to service. However, after the move I have been experiencing a serious case of micro bubbles in the return lines.
I've looked at every connection and see no leaks or salt creep (may be too early to really notice salt creep).
<Could be simply the "drop"/mix of air and water in your overflow line/s>
I use Caulerpa in my refug and notice many tiny bubbles there. I'm not sure if they've always been there or not. Water is routed from the sump through the refug and then dumps it into the sump again, but first it passes over a baffle. I see no micro bubbles in the area of the sump where refug water returns and where the return pump and skimmer draw water.
I could send a picture or 2 if needed.
<Please do>
By the way, I cleaned all the lines (over flow, return) and the pumps with my garden hose. After connecting everything I had a major micro bubble problem which has lessened considerably. Some folks on RC claimed this was to be expected after a major cleaning. However, I just can't seem to stop this last bit of micro bubbles in the return lines. It is now the 7th day since the move.
Any suggestions or advice?
<Yes... the use of "filter bags" on the discharges into the sump or change in the arrangement of your plumbing ends there. Please read here re:
and the linked files above. Bob Fenner>

Overflow Gurgles 7/27/09
Hi there, I have an overflow question for my 125 gallon reef ready tank.
<Okay, hello Aaron.>
It is a 125 gallon All-Glass Reef Ready system. I have a Marineland model 4 sump in the basement directly below the tank that I built a stand for so it is right below the ceiling. About 8' from sump to top of tank. My
problems are that on the tank, the right side gurgles about once a minute.
<Usually an indication of a siphon in the line, not desirable.>
I can watch the water level rise about 2" to the upper part of the standpipe then it gurgles and drops back down.
<Definitely a siphon.>
The left side does not, but however in the sump in the basement the right side has major flow, and the left side has very little. The right side you can just see the water pouring into the chamber with tons of bubbles and lots of force and pouring onto the filter media tray, and the bio wheel turning rather fast. On the left side is very slow flow. No bubbles, no force, and just running onto the filter media trays with no force at all,
and the bio wheel spinning rather slow. When the right side gurgles in the tank you can see the rush of water in the sump as it gurgles above.
<It sounds like the right is siphoning, while the left is not.>
I have a 1" pvc drain line going straight down into the flexible (Pool hose) line with a slight upside down question mark then into the 90 that is in the sump.
<This "upside down question mark" can trap water within, leading to this kind of siphon. But another issue below.>
For returns I am using 2 mag drive 18's. The returns are not straight shots. The one on the right goes straight up through the floor to a offset with 2 45's back up into the tank. The left side goes up 90's, goes through my UV, 90's out and up into the tank. It is very noisy. I need help with, why the gurgling and up and down water level on the right side.
And why not enough force on the left side.
<First I would make sure both lines are equally aspirated/vented. You may have to remove the P traps on the overflow lines, but the real issue here just sounds like too much return flow for what these lines can handle. I would go no more than 300 gph per drain. Keep in mind even this leaves no redundancy in overflow capacity should one fail. See:
You have always been there when I need help and I really appreciate it.
P.S. When I called Marineland to ask them all they could suggest is that maybe my tank wasn't level, and was rushing more water to the right side.
I checked for level and it was off (leaning to the right) just a smidge.
The bubble in the level was just crossing the line. Could this cause problems.
<Not the problems you are facing, but others. See:
Thank you
<Welcome, Scott V.>

Re: Overflow Gurgles 7/28/09
Ok. So if it is a siphon problem, how do I fix it. Both standpipes have 1/8 holes in the top of them. Also when I first got the sump I was running the mag 7 on the left and mag 9.5 on the right. That was nowhere near enough flow.
<It will not be for total tank flow through two 1" overflow bulkheads.>
It was barely coming out of either side onto the media. So I got a mag 18 and put it on the right side, and put the 9.5 on the left.
That helped on the right side but still not enough on the left. So I finally got another mag 18 and I have plenty on both sides just a lot more on the right. If I could split it down the middle it would be perfect. I have ball valve shutoffs on both side and have tried tuning the right side down some but by the time I notice a difference I'm half way off on the right.
<Will be the case.>
So you think it sounds like a siphon problem. I'm not sure how that works, If you could explain it to me that would be great or just let me know if there are any solutions to the problem. I've heard of sticking a air tube down the hole.
<This can help in a pure siphoning situation. Your siphoning is caused by flowing more than the drains can handle. This causes the water level to rise, at some point enough to force more water down the drain.
This in turn creates a temporary siphon (despite having the line aspirated) that ends in that flushing noise you are hearing at the end of every cycle. You really only have two options to fix this.
One is to decrease the flow through the overflows and replace that flow with supplemental flow such as a closed loop or powerheads. The other option is to drill the back of your tank within the overflow boxes to gain more overflow capacity. A couple of 2" lines will put you in very good shape.
The downside of the latter option is the need to take the tank down to do it, but if it interests you at all, see:
http://reefercentral.com/Videos.html on the drilling process. Do also see:
http://wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm for more of an explanation on the 1" line issues.>
What would that do.
Please let me know what you think.
Thank you so much
<Welcome, Scott V.>

Re: Overflow Gurgles 7/29/09
This all makes sense but why on the right side only.
<Likely the plumbing configuration in the line itself. I suspect it likely has more horizontal runs (or longer)/turns/fittings?.>
If I changed the mag 18 back to a mag 9.5 on the right side of the sump and left the 18 on the left would that make any difference...
I just don't understand why one side has 2X's as much coming into the sump than the other.
<Something about the line is making more prone to siphoning. All things equal, both drains would experience the issue with this flow. Do you maybe have pics of the lines?>
Thanks so much for your help. You all are great..
<Welcome, Scott V.>

Leak in my over flow siphon box 2/12/09 I had to build a overflow/siphon box to get water into my wet/dry sump filter. My tank has to sit to close to the wall and could not find a box thin enough. When it came time to test for leaks I ended up with a few that would not seal by reapplying solvent and clamping the affected areas. Also I have a spot around the drain tubes where the polycarbonate sheet developed several stress cracks that are all the way through the sheet and water leaks out slowly. How can I seal the box when I can not get to the inside to apply silicone? <If you have gaps large enough that you cannot get them to solvent weld, then you may need to use a two part plastic epoxy. If you can't get to the inside of it, apply it to the outside...it won't be pretty, but it will work. As far as the sheet where the drains come through, I would likely put another piece on there to strengthen it. The fact that there are cracks bad enough to actually leak is concerning.> Lee Bowles <Scott V.>

Oceanic RR Overflow Question'¦Stopping Seepage -- 02/06/09 Hi All, <<Howdy Drew>> As always, I thank everyone at WWM for their valued opinion! <<Quite welcome mate>> Just a quick-hit question today, so I'll try to make this painless. I recently upgraded my 90 gal bowfront, undrilled tank to an Ultimate 120 with the dual MegaFlows. <<Ah yes'¦the 1' misnomer>> I'm SOOOO happy to no longer have to worry about the CPR external overflow losing its siphon! I know the general sentiment with these MegaFlows, but the 1" drains work well for me and I supplement with additional high flow by other means, so I really can't complain much. <<Mmm, not so much a problem with the 1' drains themselves'¦as you state, water flow can be supplemented in other ways and personally, I prefer to limit the volume of water pushed through a sump to simplify plumbing and noise hassles'¦I just wish the company wouldn't advertise to the uninitiated a 'safe' gravity flow rate of 300gph as 'MegaFlow'> The tank came with the stock overflow kits, with Durso-style standpipes. They run quietly and I'm actually quite happy with them. <<Excellent>> Now, on to my question. When I cut power to the tank, I get a slight amount of leakage from the drain lines into the sump. Obviously, a tad amount is leaking from between the standpipe and the bulkhead on both sides. <<Easily rectified>> It's not much, but it does trickle out. This makes me wonder: the overflow draws water from the bottom, middle and top - so in an extended power outage, what's to prevent the whole tank from draining to the bottom slats of the overflow? <<Indeed'¦given enough time as you imply>> I don't want to glue the standpipes into the bulkheads, but I'm wondering what I can do to minimize any risk of draining the tank during an outage. <<No need to 'glue''¦ Remove the standpipes and smear some Silicone adhesive on the threads and replace the standpipe. The Silicone will not 'glue' the standpipe to the bulkhead'¦but if allowed to cure before replacing the water in the tank, it will create a seal that will stop that annoying seepage at the bulkhead junction>> I'm running with RO water now and about to start building it up, but I'd like to get this resolved before proceeding. Thoughts? <<As indicated'¦ Drain the tank'¦seal the standpipe/bulkhead threads with Silicone'¦let cure'¦refill the tank>> Hopefully this made sense! <<Hopefully I did too!>> Thanks again, Drew <<Happy to assist. EricR>>

Leak in Seam of my Overflow Box 1/22/09 I built an overflow/siphon box to get water to my wet dry system. When I leak tested it I had a few cracks that I fixed by re-applying solvent and clamping. It fixed all but one spot. I fear that the edges were not completely flush at that spot when first put together. How can I fix it? <If it is not too terrible a gap the Weldon 16 can fill the gap on something non-structural such as this. Otherwise a acrylic patch over the seam will do the trick.> Also how can I fix a stress crack that is open to both sides of the sheet? <Why did it stress/crack? From the weight of the box hanging on the tank?> Will applying solvent into the cracks repair them? <It will if they are tight fitting, but you do need to assess the reason for the crack.> Lee Bowles <Scott V.>

Re: Leak in Seam of my Overflow Box 1/26/09 The stress cracks came when I clamped together two pieces and applied solvent. I think maybe that it was clamped to tight? <Likely, with good fitting pieces is should take very little pressure to bring them together. I even just use black electricians tape when I have odd pieces that are difficult to clamp, it really should not take much pressure.> It is plenty strong and is not in an area where it will be stressed. It just created a spot where a very small amount of water leaks out, a small drop in an hour. The rest of the leaks I fixed by reclamping and applying more solvent. The final spot is in the bottom corner and can not be reached by hand from the inside. To hang it on the back of the tank it had to be very narrow. I need to travel seventeen inches down through an inch and a half slot to reach it. Is there something that could be poured down into to seal it? <OK, you will want to get some Weld-On 16, the thick stuff in the tube (or you can make your own with your current solvent and some acrylic shavings). Get yourself a straw or a piece of tubing that can reach the spot that is leaking and send some of the 16 down there. There are a few unorthodox ways I could tell you to do this that would have many acrylic fabricators shuddering (but come on, we have all done these things!), but this will fix your leak without making too much of an unsightly mess! Scott V.>

Bulkhead depression, sel.   1/3/09 Well, being new at this I've been reading your site for 6 months now and still don't have a drop of H20 yet in the aquarium. <Heeee! Like many good things, experiences... savouring the anticipation is very worthwhile> So much research to do and all. All was going well until I finally filled up the overflow last night to test it out w/the new sump. Then the depression set in as the bulkhead was leaking. Today I tried tightening it to no avail. Finally I decided to just undo the return line completely and just redo it. I then noticed hairline cracks in the bulkhead. <Unusual...> Unfortunately, despite my several months of research I neglected drill hole size and ended up w/the standard ¾ hole size of 1 ½. The schedule 80 is 1 5/8. <Mmm, no need for Sch 80... replace it/this with a schedule 40 fitting... plenty strong enough> I thought I'd pass along my experience and recommend to everyone who's new at, this like me, to go with the heavier duty bulkhead. Do you know of any brands that are sturdier than the flimsy standard ones (marine depot) that will fit into a 1 ½ hole. I'm going to order a new one today. <Do contact Mike or Scott at Glass-Holes (.com)... There are differences of opinion re how many gaskets to use, in, and/or out, I like a smear of Silastic...> Thanks for any help! Sorry if I sound depressed as I'm sure this isn't too big a deal but setting this all up is a bit overwhelming for sure. :-) <Oh, no need to explain, apologize... I have indeed been here, done this... The good news, all is easily fixable at this point> Ps. If Bob happens to get this I'm the guy you meet at Reefapalooza in so-cal with my family sitting there with the classic �When is this going to be done� look on their faces'¦. <Heeeee! I do recall. Cheers, Bob Fenner>

Re: Bulkhead depression - follow-up 1/3/09 Bob, thanks for the words of encouragement! I'd be lying if I said I didn't need it. <Glad to conspire with you John> Anyway, I bought another bulkhead last night at my LFS and I plumbed it up again, put a drop or so on the gasket and after playing with the lock nut tightness the best I could get was a drop an hour leak. I tried washer on both sides and just one side to no avail. My gut feel is that the gap between the bulkhead and the acrylic is just a little too big, therefore causing the washer to acrylic contact surface area being too small. I can't think of any other logical explanation as to why this is leaking. <Ahh... I do have a prescribed solution... as alluded to in our last email... see the end> My LFS stated that if I want to I can expand the hole easily with a Dremel and a round sandpaper bit. <Mmm, nah!> He seemed very confident as long as you go in a circular motion and don't rush it. This allows for a 1" bulkhead or the beefier 3/4". <Is this a discharge or an intake fitting? If a drain, go with the larger, largest diameter you can... if feeding into the system, no sense making the diameter larger than the size of the pumps discharge volute... which should be the same as the plumbing ID> I'd need to go from 1 1/2 to 1 5/8 hole which isn't much. He wasn't pushing the idea, just offering it as a possible solution. This idea is starting to grow on me as it seems like more of a once and for all type of solution. I'll will also contact Mike and/or Scott today. <I would... Much easier to SLOWLY insert a bit and drill through all at once...> On a separate note, I'm starting to look at lighting now. Background info: 65 gallon tall acrylic (the 'tall' is turning out to be a pain - another learning experience - can't fit a 4 footer though). 30X16X16 sump w/sock + refugium combo (Truvu) located behind the wall in another room. Vertex IN80 skimmer One 6 X 6 overflow in the corner. 1" with 3/4" return. Yep, I know. Not ideal. <... I would re-drill the overflow... actually make two lines here...> I'm planning the water level in the sump now for BOTH overflow block (pump all water back in) and power off conditions. <Good> I'd really like LED lighting but it's just too expensive still at this point. So I'm thinking about one of those all in one units with 2 Metal Halides, moon led, etc.. Something like this: http://www.marinedepot.com/ps_ViewItem~action~view~idProduct~CU01063~ idCategory~FILTFIMHMMMDMLM5~category~36in~vendor~.html <Fancy schmancy... see my comments below> Does something like this just lay on top of the acrylic tank? <It can in general... got to keep the MH away from the acrylic though... Better to have all on a "perch", can be made or purchased... Mount it at least four inches, six is better, away from the acrylic... Which has a surprisingly low flash point... yep, fire hazard> Seems like one metal halide might be enough, and cheaper... <Yes... and IMO unnecessary... I'd just stick with fluorescents here... VHO, PCs... are sufficient> I planning FOWLR, but I can tell I'm going to get into the reef stuff really quick as I'm already fascinated by the variety of life, just don't want to jump in too quickly; and getting it not to leak w/one clown would put me in an ecstatic state at this point. I like the concept of T5's for efficiency, but it seems like there's just a blanketing effect of white light. <Mmm, no... not with decent reflectors> Finally, is egg crate under the sugar sand for rock stability, a good idea? Any drawbacks to putting egg crate on the bottom of the tank. <Mostly just makes it harder to stir the sand... I would leave out the egg crate, just set the larger rock pieces directly on the bottom...> Thanks so much again for your time. Appreciate it. <Oh! And about the through hull leak... as stated before, I would make a thin smear of 100% Silicone Rubber on both sides of the gaskets (yes, one on either side of the tank if you have two... or just on the outside (gasket) if you only have one... including a thin smear of Silastic on the threads nearest the bulkhead to give a little lock to the nut... Bob Fenner>

Re: Bulkhead depression - follow-up 1/3/09 Bob, thanks for the quick reply! <Welcome John> Bulkhead Leak: The fitting that's leaking is the 3/4 return line (1.5 in hole). The 1" drain line right next to it seems ok so far. A bit of digression here, but I'm wondering if I shouldn't have used silicon O ring lubricant? <Mmm, no... Silastic... a bit stickier... and it too does "give" if/when one want to un-do the work some time later> Anyway, a bit confused on your responses. On expanding the 1.5 in hole... "I would... Much easier to SLOWLY insert a bit and drill through all at once." I can't picture this. My Dremel sandpaper bits are fairly small, about .5 in diameter. Can you please clarify? <Easier for me to fit a bit against the current hole to drill out the extra eighth inch... Am hoping ScottV will explain better> On the technique: "I would make a thin smear of 100% Silicone Rubber on both sides of the gaskets (yes, one on either side of the tank if you have two... or just on the outside (gasket) if you only have one... including a thin smear of Silastic on the threads nearest the bulkhead to give a little lock to the nut". I looked up Silastic and it's made by Dow and there seems to be 3 types. Home depot and MDepot have no results for Silastic in their search boxes (web), which surprised me. Where do I get this? <All 100% ones are identical (does make sense eh?)... Some just say "For Aquarium Use"... but 100% is 100%> You also mention silicone rubber. Is this the same as aquarium silicone sealant? <It is> I did check the silicone faq on WWM and most of the ?'s are related to glass aquariums leaking, etc.... Lighting & Egg Crate: Got it! Thanks! I'm getting there with you support! I can't thank you enough for this advice, invaluable really. :) <Again, certainly welcome. BobF>

Re: Bulkhead depression - final follow-up 1/22/09 Thought I'd pass along a follow up to my bulkhead leak situation. I was able to Dremel the holes to a slightly bigger size without too much difficulty and had a real snug fit on the bigger sch. 80 bulkheads. It's up and running now with no leaks at least for one hour, time will tell. <Good.> The water level does bounce up and down a bit in the overflow due to the Durso? I expanded the hole to 1/8" at the top and now it bounces about 1/4 near the inlet pipe. Is this about right? <This should be very constant barring the disturbance on the water's surface due to the flow. If the actual water level is fluctuating even a ¼' it is indicative a bit of siphoning, with a few possible causes. What size bulkhead did you end up with for this overflow and what flow are you running? Do you have any slurping or flushing sounds?> Now it's on to figuring out how to get the new vertex skimmer up and running. Then buying some rock. Is it ok to put a DSB into a separate container in my sump? <Sure.> I'm thinking if I ever do want to remove it or need to work on the sump for some reason, I can just pull it out the DSB in separate container sections. <A fine way to do it.> Thanks again for the help. I think my family had a bit of the 'light at the end of the tunnel' look today which was really encouraging. :) <Happy we have been of service, welcome, Scott V.>

Overflow Sizing 1/7/09 Hey Crew, <David> I was reading through your daily FAQs over lunch break (as usual, great read!) and noticed a common/recurring question that has me concerned. From what I've gathered based on responses, 1" drains should not be trusted with more then 300gph of flow apiece. What concerns me, is that my 2 year old Perfecto 180gal "reef ready" tank came from the factory with bulkhead fittings that are sized to slip 1" (inner diameter) PVC into. I have been running two "1200gph" (at zero head) Mag12s for returning water from the sump, with very direct plumbing with minimal angles, and pumps nearly directly under holes in aquarium. I would be surprised if these pumps are losing over ¼ of their pressure from these straight forward lines (especially considering they are rated at 1100gph at the head height my tank would demand) If they are only producing ¾ flow, that would still be 1800gph which is three times the combined flow I've read on WetWeb responses as appropriate my two overflows. I have had this tank up and running for 2 years without any drainage/overflowing issues, but I certainly don't want a surprise one evening! Am I missing something obvious with calculations? Would Marineland/perfecto truly design a "reef ready" aquarium incapable of safely handling more then 3x total tank turnover through its overflows? <Ah, this could get quite technical, but you have to consider friction loss also. A 90 will give you a loss equal to having an additional 2.25 of 1" PVC, a 45 equal to 1.40, a gate valve equal to 0.6, and a branch tee equal to 6. As you can see, lost gph can add up quite fast. Another factor to consider is the specific gravity of the fluid the Mag 12 has to pump, that will add to the equation as salt water is heavier than fresh and needs a little more power to pump. The pump manufacturers do not state how they arrived at their numbers but I'm guessing the testing was done with fresh water. And then you have the performance curve of the pump to consider which factors around head height, viscosity, etc. All things said, you just cannot compute based on the length of head being used. Another side to consider is the distance between the pump and the sump, this can also add to gph loss, so it is best to keep the pump as close to the sump as possible. I'm betting my money that you are not getting 1100gph at the outlet. If you really want to dive into this, go here. http://www.advancedaquarist.com/issues/jan2003/featurejp.htm> Thank you! <You're welcome. James (Salty Dog)> -David

Re: Overflow Sizing, w/ ScottV's valuable addenda 1/8/09 Thank you for the extremely informative response! <You're welcome.> I completely agree - 1100gph actual output in real-world conditions from 1200gph rated pumps would be absurdly optimistic. I had assumed 3/4 (900gph) per pump was reasonable (based on the wonderful article you've linked in your prior response), but I had not considered salt water viscosity, head loss due to plumbing considerations within the tank, and the possibility that the GPH ratings on these pumps may be flat-out wrong. <I don't know if I'd say they are wrong, just do not know how they were arrived at.> In my particular case, I have 1.25" flex pipe clamped from the 1" PVC screwed onto pumps (actually submerged within sump), up to the 1" PVC mounted directly to bulkheads without any hard bends, gate valves, or any Tees under the tank. <If the flex pipe is the ribbed variety, the friction loss will be even greater.> At least two places I did screw up with my assumptions were that I did not consider Ts and various plumbing aspects (such as the original jointed tubing and spout-heads) that are within the tank, or salt water viscosity vs. fresh water (or whatever is used by this particular manufacturer) for rating pumps. To my original concern, even if my pumps have 50% loss due to head/friction (only total 1200gph achieved out of total 2400gph theoretical output from pumps), that would still be 200% of the flow I'm seeing recommended on responses to others based on my overflow plumbing size (300gph per overflow, 600gph total). Should I just shrug it off as "Marineland/perfecto" magical overflows, or would it be wise to unhook one of the pumps (and lose the safety/redundancy of running two return pumps) to alleviate any potential risks of overflowing? <I'd leave things as they are, if your sump is sized correctly (about 25 gallons), you should be fine. You can find out by multiplying the length x width x height and dividing by 231. This will give you the gallon capacity of your sump. > Thank you yet again for what's always highly informative, educational responses to real-life aquatic issues! You guys (and gals) are awesome! <We thank you for the compliment and you're welcome. James (Salty Dog)> <<A bit to add regarding the 1" bulkheads. Partial/full siphoning and allowing some inches of water to buildup above the standpipe can all have a significant impact on the flow these lines are capable of. The 300 gph number is for a truly gravity fed line with no siphoning. This is far and away the safest, most reliable way to run these. Any other method relies on a balance between the overflow and the return, a recipe for disaster. That being said, anybody with a vessel of measured volume and a timer can test both the 1" line and the flow from the return pumps. Most people would be shocked to know what their pump is actually pumping! Do also keep in mind that running these at the limit also provides for no redundancy. Scott V.>>

NOISE Question Noise Question, Overflows 12/2/08 Folks � <Andy.> I am finally up and running after three months of intensive research on your site and others. I believe it was worth the wait, however, the one thing I was scared of: the dreaded drain noise, is still baffling me after trying different methods to eliminate/reduce it. <Uh-oh!> I have a 150 new AG "reef ready" tank with flex hose for drains, one is 5 ft the, other is 3 ft in length. The shorter 3 ft piece is kind of curved because there is only about a 6" distance from the tank bulkhead to the sump bulkhead. I am told this "almost" loop is not good, however, this is the drain that surges the least...it's the longer 5 ft piece that is louder even though it's straighter. <A more direct route would be better.> The 5ft piece surges like crazy even after I turned down the gate valves on the Mag 18 almost to a trickle. ( I should have bought a Mag12, I guess) I am guessing I have no more than 300 gph for each 1" drain, and IAW with your site that should be sufficient for noise purposes. <Is flat out the limit of what they can handle.> However, this drain line even stops draining for ~ 1 second intervals and than drains again...like constant convulsions. <Siphoning.> I tried aspirating the Dursos with 3/8" tubing and sticking it to different depths...nothing. I made special fittings for the long length so it won't curve almost 90 degrees to the vertical sump bulkhead...it now enter parallel to the sump to a 1" PVC connected to a 1.25" T with a end cap on the top side, which I drilled with a 3/8" hole and I also aspirated. Still surging...maybe marginally better at best. Is this surging safe? I mean is bad to leave it like this if I did not care about the noise? <It is not safe, the overflow basically relies on the siphon to restart every few seconds to drain. If the siphon did not restart'¦> The only thing left that I am thinking is taking off the sump bulkheads off, so I can have enough room for both flex hoses to place in their respective filter socks, maybe with a 45 degree PVC elbow attached to the drain lines (not using the original sump bulkheads). This would be a "softer" and lower landing in the sump. I would have never thought that water gravity draining is so temperamental? <They can be very much.> Besides drilling a new hole, what other options do I have? <If you are indeed running 300 gph or less through each your drains will work, but with no redundancy. As for the siphoning, I suspect there is somewhere in this line (I am having trouble picturing the whole run) that is acting somewhat as a P trap, pooling water inside the line. This can cause siphoning issues even with the line aspirated above. The siphoning cycle within the line will become apparent up above as in allows water to flow, then stops, starts, stops and so on.> Respectfully, Andy <I do hope this helps, if not do write back with some more details (maybe a pic) of the lines/run. Scott V.>

Loud Overflow (Another Overwhelmed 'Mega' Drain) -- 07/17/08 I have recently set up a 90 gallon reef tank with a central inside the tank standard Mega overflow kit. <<As yes, the grossly overstated 1-inch overflow kit>> It drains through a one-inch bulkhead into a 30gallon sump below the stand. I have been doing a lot of research concerning Stockman, Durso, and Hofer gurgle overflow pipe constructs that supposedly will quiet down the gurgling noise. <<Will help'¦as long as you aren't simply overcoming the drain with too much flow. Regardless of what may be stated in your kit, trying to run more than 300gph through a 1-inch gravity drain is trouble>> I am still confused which one will work best for an inside the tank overflow which is 24 inches tall. <<Differing means to the same end. All will probably elicit a change'¦finding which one fits and performs best for your situation/setup will take some experimentation>> I am worried about handling the outflow. <<'¦?>> I have a Gen-X pcx-40 pump <<Yikes! Unless you have a ton of headloss or this pump is throttled way-back, it is way too much pump for a single 1-inch drain (see my earlier comment re)! You have a dangerous potential for flooding, and as you have discovered, noisy siphon effect going>> which I plumbed into our crawlspace for noise control, and the standard design of the Hofer gurgle pipe only handles 5-600 gph. <<In reality this is plenty'¦the concern is over how much flow your 1-inch drain can safely handle (300gph)>> I was trying to determine should I increase the size of Hofer gurgle to 1.5 inch and 2 inch pipe, does it need to be taller than the design on their website which is only 5 inches tall and then extend the air tubing above the water line, or is there a better option for noise control that can handle the overflow? <<I would follow the recommendations of the designers'¦and visit/query the reef forums for others input re their design modifications, if any. But the real issue you need to address is flow rate. As stated, you just have too much water being pumped to the tank for the 1-inch overflow to handle. I would suggest you downsize the return pump (best option), or at the least install a gate valve on the output side of the pump to reduce flow to that which the drain can safely handle'¦even with an aftermarket 'gurgle pipe'>><RMF would have another drain line drilled, fitted.> Thanks, Mark <<Good luck with your plumbing project. EricR>>

Tank plumbing Siphoning Overflow 7/1/08 I was setting up the plumbing for a 20 gallon tank I'm using as a frag tank. It is drilled from the bottom with a 2" PVC going straight down into a 20 gallon refugium/sump. <A serious overflow for a 20 gal!> Its a straight drop into the refugium and I have a 'T' in the PVC and under the 'T' a ball valve, so that I can regulate the flow go into the refugium and the rest of the water will be diverted into the side of the sump with the mechanical filter, and in the middle of the sump is the return. I built the stand as well but didn't get around to putting any paneling on it so its quite loud. To solve this I extended the PVC down into water, realizing this would make that lovely toilet flushing sound, but thinking it would be more tolerable than the sound of the water crashing into the sump. <Both are curable.> My question is can I drill a hole into the PVC just above the waterline to solve the problem of the toilet flushing sound? <Yes, tis the solution, even with such a large drain line. Drill just large enough to slip a piece of vinyl or other tubing in to slide up and down, you will need the end of the line inside the pipe about an inch or two below the waterline inside the pipe to prevent siphoning.> If not, is there any other way to work around this problem? <Nope, you have the solution.> Given the choice, I'll take the toilet flushing over a waterfall, but it would be nice to be able to fix it. <You can fix both.> Thanks. <Welcome, Scott V>

Fish stuck in overflow with no way out! - 06/08/2007 Hi, I have a Blackspot hogfish that has only been in my tank for about a week and he somehow managed to get into one of the dual overflows. I have been trying to catch him with a net for over an hour but with all of the plumbing, it is proving impossible. I was wondering if there are any safe alternative solutions for his relocations back to the main tank. My husband wants to try a small shop vac but this just doesn't sound safe to me?!?!? Please help me save my fish! Thanks for any suggestions, Alison <Mmm, it may well be that the easiest, simplest approach here is to turn off all pumping and dumping this fish back in to the main display... and, screen all intakes going forward. Bob Fenner>

Overflow... Not reef ready 4/29/08 I have a reef ready 90 with the built in overflow in the back. (older style?) I have a mag 9.5 return pump. The return goes from the sump to the bottom of the standpipe, maybe 24" then up into the overflow box another 24". <OK> The problem is I am getting a lot of noise from the overflow, I hear most of it from the top of the tank. The tank is equipped with the stock standpipes. After Googling I found that the overflow is rated for 600gph, <And in reality only flow 300 without issues.> and the mag 9 is 800gph @ 48" head, so why would I still be getting the air noise? Is there an adjustment I can make to make it more quiet? <The fact of the matter is the 1' drain provided in these overflows cannot handle nearly what the Mag 9.5 can pump back up to the tank. At the very least this will be evident with the noise you are experiencing, at the worst you will end up with water on the floor. By forcing the drain to handle more than it can you will be forcing it to siphon somewhat, creating the gurgling and flushing noises you are hearing. You will need to put a ball valve on the output of the Mag and restrict the flow until the noise subsides.> Thanks in advance <Welcome, good luck, Scott V.>

Algae in Overflow Box 3/15/08 Greetings Crew. <Hello Andy.> I have a question regarding solutions to algal growth in my overflow box. My tank is not pre-drilled, so I have the old style hang-on-the-back overflow box. In December, I converted from a T5 HO lighting fixture to a larger metal halide fixture. <OK> Since I made this change, I've noticed that the first internal cavity of my overflow box tends to develop a large, thick mat of green hair algae that restricts water flow into my sump. <This happens, it is a pain!> A portion of the actinic PC bulbs in my new fixture hangs over my overflow box, whereas my old fixture was narrower and no part of it sat over the overflow box. I purchased a small flexible, spring-like filter cleaning brush and, after MUCH manipulation, was able to get it up and into the cavity. I was able to remove much of the algae, but this was a very difficult task because of resistance created by the algae and structure of the cavity and the flexibility of the brush. At first, I had luck only in scrubbing the sides of the cavity, as the brush would orient only outwards within the cavity. So, I decided to feed the brush handle through a short piece of PVC pipe once I got the brush inside the cavity, and this allowed for a little more stability of the brush and let me access more of the internal cavity. However, even using this method I was not able to completely clean the cavity. This was a lot of work--took me a good 2 hours of manipulation, moving my fixture off the tank, etc. Does anyone know of a better way, or a better tool, other than taking the overflow box off and soaking it in bleach for a few hours? <Manually loosening a rinsing out is generally the best way, still a pain as you describe.> I was thinking of covering my overflow box in aluminum foil to keep light out of the box, but I worry about the unintentional addition of aluminum/corrosion byproducts into my display caused by runoff if any water splashes, etc. on the foil. Thanks for any insight. Andy <In your situation I would take the overflow box off, lightly sand the outside and paint it. This will keep the light out of it, preventing such a proliferation of the algae inside. Krylon Fusion spray paint will work well for this, it dries fast and adheres well to plastics. Welcome, I hope this helps you out, Scott V.> 

Please Help! At My Wits End Trying to Solve This Problem... (Another Overwhelmed 'Mega' Overflow?) -- 03/03/08 I have a 150 gallon glass aquarium with Megaflow Overflow system, Euro-Reef skimmer with Sedra pump, and 2 Mag-Drive pumps (950 gph). <<'¦! Is this for each!? I'm guessing this 'Megaflow' system (can you hear the sarcasm in my voice [grin]), consists of a single 1' drain, yes? Realistically, this would limit you to about 300gph en toto for the return pump(s)'¦after headloss>> The system is 5 years old. The pumps are all originals but well cleaned and cared for. I can honestly say the system has been virtually silent since I purchased a Euro-Reef Isopad soon after system was set up 5 years ago. <<Ah, yes'¦isolating pump vibration can make a remarkable difference>> About a week ago a major change occurred. I came home to very loud rushing water noise (like toilet flushing constantly). <<Mmm, a siphon surge'¦generally means you are pushing more water to the tank than the overflows/drains can safely handle>> The pumps and skimmer appeared to be working well with no apparent air leaks. The drain pipe/return pipe appears tight in bulkhead and in correct position. No matter what I do to try to quiet the system nothing works. When I turned the system off I heard an extreme high whining noise (like something was stuck in line). <<Hmmm'¦or maybe sucking/pushing are through a very small leak (pinhole)>> I continued to turn the system on and off until I could no longer hear the whine. <<'¦?>> The system is not hard plumbed and usually I can "burp" the air out easily by moving the flexible down lines a couple of times. <<Mmm, better to aspirate these if this is a continual problem. This involves inserting a length of small-diameter tubing down the overflow pipe to allow air to escape when the system is 'running.' Determining the best length/diameter for the tubing usually requires a bit of trial-and-error>> This has no effect on the noise now. <<Agreed'¦not a panacea>> The noise (rushing water and air) seems to originate along the lines draining into sump or up in the aquarium, not in the sump. <<Indeed'¦a result of too much flow>> Adjusting the water level using the air intake elbow has not been successful. The drain pipe and return pipes seem to be firmly in place in the bulkheads. I know of nothing that could have been sucked into the system. I did have a problem with overgrowth of sponges over my live rock etc when I was feeding my puffer mussels daily. The sponges were evident and growing out of the overflow. I fear that somehow they are constricting my lines internally? Is this possible, how do I eradicate? <<This is possible'¦and would explain the change in the systems' performance'¦Replacing the drain pipe/tubing is an option, but I think you have other issues here as well. This problem is almost certainly an issue with 'too much water volume' being pushed down the drain line. Frankly, with the return pumps you list, I'm amazed you haven't had a serious flood before now. Those Mag-Drive pumps must be working against some serious head pressures. Even so, it sounds like your drain has been operating in a dangerous 'siphon' mode where the slightest obstruction; in this case possible buildup of organic matter, can cause serious problems. I think you were lucky this time in that the drain was able to 'surge' and keep up with the flow, albeit in a very noisy/annoying manner, and didn't just back water up all over your floor>> I am at a loss as to what do next. <<If you don't have gate-valves plumbed on the return side of the pumps (recommended), try turning off one of the return pumps to reduce the return flow and see what happens. As stated, with the 1' drain line you should shoot for a flow-/drain-rate of no more than 300gph. And obviously, come up with alternative methods for producing necessary 'water movement' within the display>> Thank you for your assistance. Leslie <<Give the flow reduction a try, Leslie'¦and write back to discuss further if you wish. Regards, Eric Russell>>

Follow Up Note On My Email To You on 3/3/08 (Sys. Plumbing/Bristleworms/Puffer) -- 03-15-08 I wanted to thank Eric Russell for his assistance on 3/3/08. <<Eric here'¦you are quite welcome, Leslie>> I was so frustrated that I was ready to give my fish away (or worse) and close down the system! <<I do recall>> He gave me the support and guidance to get through a really miserable few days until my aquarium was fully functioning again and my 4 charges were alive and well. (This includes my original 5+ year old dogface puffer, 5 year old Foxface, 4 year old Picasso trigger and 3.5 year old hippo tang.) <<Is rewarding to know>> Thank you, thank you Eric, as I thought my puffer was a goner , not eating for 4 days. <<Most welcome again, my friend>> You guys and gals probably do know what a wonderful service you provide and you are so appreciated in 911 situations. <<It truly is our wish for you/the hobby to succeed'¦thank you for the kind words>> I had written because my 150 gallon all glass aquarium with MegaFlows had started gurgling and siphoning. The system is 5+ years old and usually quiet. The noise was a very sudden change and no matter what I tried nothing worked. With Eric's advice I tried to aspirate the air. Did not work, if anything noise, gurgling just became worse. <<It can take quite a bit of fiddling to find the right combination of tubing diameter and insertion length'¦but still'¦is no panacea>> Eric confirmed my fear that it was possible that my drains ( 2 drains, each 1"diameter ) could be plugged from organic matter. (Ii fed my puffer daily mussels to keep his beak in check). <<Indeed'¦many cryptic organisms find this environment agreeable to them>> Eric suggested I might need new lines. <<Is often the simplest approach to this issue>> I also suspected my Euro-Reef skimmer might be at fault for the extra air being pulled into the system. It still produced good skimmate amounts but was getting more and more difficult to start pump. At times required pump to be disconnected from skimmer and tilted around before it would start. <<Ah, yes'¦I very recently had to replace all three Sedra pumps on my own ER skimmer (made the switch/upgrade to the ER-modded Eheim pumps)>> Anyway, due to undergoing treatment for a medical condition, I am quite weak right now, and had to hire my local LFS to come to my home. They determined there was nothing wrong with skimmer function (wrong) and thought the flow was just fine, did not agree noise was anything but normal. <<Disappointing to know>> I insisted they break system down and evaluate. <<Excellent>> This took them over 2 hours (at $85.00 an hour, <<Yikes! Maybe I am in the wrong biz'¦ [grin}>> I know MD's that are less expensive, but who's going to argue at this point. <<Actually, from what I've read I think that fee is about 'median' and not unreasonable. Regardless'¦you should still expect them to know what they are doing/provide quality service>> The Mag 9.5 pumps were fine, but the drain lines were at least 50% clogged with fibrous tissues (sponges?) <<Quite likely>> but worse, thousands of bristle worms. <<Not the monsters many folks think them to be. Can be/are quite beneficial detritivores'¦although extremely high population densities can be an indicator of excess organic material (overfeeding)>> Unfortunately, when the drain lines were reinstalled and the system started up hundreds of baby and not so baby bristle worms were blown into my aquarium. This was so upsetting as I keep a meticulous aquarium (at least the parts I can see). <<Relax my friend, no reason to be upset at this point. Back off a bit on the feedings and the worm population should adjust accordingly>> I do every other day 8-gallon water changes and visually the aquarium looks pristine. <<Ah, but as you are learning'¦much going on/present that isn't always 'visible' to the naked eye>> My puffer requires this and I think this is why he has lived so long. But I am side tracking, sorry... <<No worries'¦all pertinent/worth sharing>> Anyway, when the LFS left my home I was left with a sump full of bristle worms. Most were about an eighth of an inch long but there were many big ones, 1-2 inches in size. <<Mmm'¦have seen much bigger, and are of little concern as stated. Think about it, these worms have been in your system for years'¦you didn't have any problems re, or even think about them when you didn't 'see' them>> Also 2 big piles of worms (I mean about 2 inches high) were deposited in the aquarium. My trigger was going crazy but even he wasn't hungry enough to clear them. As it was about 8 pm and dark by now I quickly did a 20 gallon water change and collapsed into bed. Next Am I moved live rock from 1/4th of aquarium and of course there were piles of the worms under it. I still need to continue my quest and break down the other 3/4ths of aquarium and vacuum up what I can). <<You can do this if you wish'¦but is not necessary in my opinion>> Any thoughts on how to rid the strangers? <<You really don't want to be 'rid' of them'¦.they serve a very useful purpose. But as implied earlier, reducing excess foodstuffs in the tank will limit the population>> I don't want them growing inches long. <<Too late [grin]'¦but no reason to panic>> I will not overfeed aquarium but at this point I want them out! <<These organisms are a necessary and useful component of a 'balanced' system>> I agitated the sump water in the skimmer and it picked up several hundred more from there. Then I got really discouraged and just completely emptied the entire sump and cleaned it all out of any water and worms. The doorbell rang with my new Sedra 5000 pump for skimmer, it was perfect timing. <<Indeed'¦a well functioning skimmer will also help with the excess organic load, obviously>> Even the fiber block that is in sump after the floss/ carbon/ was filled with baby bristle worms. The foam on the Euro-Reef skimmer full too. Now skimmer with new pump is up and going, lines are clean, about 100 gallons of water have been changed in the last 3 days. Gurgling has stopped, no siphoning anymore either. <<Yay!>> Now I have one question. How do I prevent this from occurring again in 3-4 years? <<Hmm'¦it's not likely it can be 'prevented''¦but reducing dissolved organics in the water that feed the sponges will slow down their growth/expansion. Also'¦reducing flow rates a bit (i.e. -- not maximizing/overwhelming the drain's capacity) will allow a bit of 'wiggle room' for such growths>> I don't want to feed my puffer any more mussels after seeing this residue, <<Oh'¦don't stop altogether'¦just be more judicious re>> also I think the sponges really picked up growth when I started putting Selcon on food about 9 months ago. <<Mmm, yes'¦while quite beneficial, it has been my experience that use of this and other such food boosters requires careful use as they can be abused. I do recommend you keep using the Selcon'¦but keep its use to no more than once or twice a week as a food soak>> What do I do to keep his beak from growing so fast? <<As stated'¦don't 'completely stop' feeding shellfish to the puffer, but rather cut back a bit maybe (as well as other foods/potential over-feedings)'¦and do also add some chemical filtration (carbon/Poly-Filter) to your system>> He only occasionally takes bites out of the coralline live rock. I was trying to think of a way I could attach his favorite big hard algae wafer to a mussel shell. That way he would still bite hard against the shell and keep beak in check. <<Keep feeding what the fishes need/require'¦and 'step-up' the filtration/husbandry to cope re>> The LFS said that puffers don't live long when they are at the size of mine but I just don't believe that. <<'¦?! And they based that statement on'¦? Seems a ridiculous thing to say, to me>> He has done wonderfully and never has had a disease. <<Testament to your good care and a proper diet, no doubt>> What is the oldest age you know for a captive dogface? <<Have heard this can be more than a decade>> Well, that is the end of my tale. I write to say thank you but also so others can learn from my bad experience and hopefully save some agony. <<Many thanks for sharing>> Thank you Eric and all of the team. <<We are all pleased to assist>> Oh, I did also have valves added as recommended by Eric. <<Excellent move!>> Sincerely, Leslie <<Be chatting'¦ Eric Russell>>

More Overflow Woes 2/23/08 Hello again! <Hello Jaime.> Here is a breakdown of my system and my problems...oh boy here goes. I have a 125 gallon reef tank which was recently (3wks) upgraded from a 75 gallon. I have a CPR continuous siphon overflow (with 2 one inch bulkheads) an oceanic type 2 sump and a Mag flow 8 (1500 gallons per hour). <Mag 18?> There is PVC cemented into the overflow going down into the unit below and PVC Teflon taped together for the return. 3 times so far the 125 has overflowed from the top...the water level rises and "boom!!" mess! Thank god I have been there every time. <Not good.> The tank is almost level, maybe a hair off to the front. <Get yourself a level and check this, fix the problem if it is not level.> The overflow has been getting some air trapped in the neck no matter how much I suck it out...due to the tiniest variation in levelness? <And likely running to/past capacity. A realistic, real world and safe expectation out of this overflow will be just north of 600 GPH. The addition of a Tom Aqualifter pump to the overflow to constantly remove any trapped air will help out immensely.> When I suck that air out sometimes the water level drops a little. (going back to normal) I even have a ball valve to slow the amount of water going back into the tank (and with that more than half closed I am putting strain on the unit) but it still overflows. <Yes, a pump that large, even throttled back so far, will strain this overflow. You are simply limited by the two 1' bulkheads here.> Someone with a brain has got to help me here!! The jerks I bought everything from want to put a "t" valve on the return part to let extra water flow back into the sump (but I do not want all that extra un-needed noise!) <Nor energy consumption, moving water that does nothing.> I wanted to just return the pump for something that is not so strong. They said no way, you already used it. Funny part is one of their employees set the whole unit up for me. <Yikes!> I can send some pictures if that would help but where do you think my problem is lying? <This is purely a pump vs. overflow capacity issue.> I have already been without adequate filtration for about 5 days and going. I have invested hundreds and hundreds of dollars here. I am sure you can understand my frustration. I haven't even been able to really enjoy the tank yet. My birthday is Monday so the soonest I can get back up to the store is Tuesday so now we are adding a few more days with crappy filtration. I would like to go up there really knowing where my problem is so I can fight my case. Thank you sooo much! Jamie <I urge you to consider the option of drilling this tank for a true gravity fed overflow. Two 1 ½' drains will do the trick here. I have included a link of yours truly drilling to give you an idea of what is involved. If you are not comfortable doing so, you should consider adding a second CPR unit like the one you have already. This will give you more flow capacity and allow you a certain amount of redundancy if one fails (keep in mind your flow is out flowing one unit). The addition of an Aqualifter or RVT powerhead is highly recommended to use with these types of overflows. You will still need to keep the pump throttled back, but not as much. Good luck, Scott V.> http://www.momsfishsupply.com/drilling_video.html

Re: More Overflow Woes 2/24/08 The guys at the fish store told me that this over flow turns that fish tank water over 10 times and hour and moves something like 1200 - 1500 gallons per hour. <It does not, as you are experiencing.> You are saying 600. Why such a huge difference between what you are saying and what they are saying? <Many factors, most notably the 'urban myth' of what a 1' bulkhead can flow. The fact of the matter is the bulkheads in this unit limit your flow.> Why would they sell me such an over powerful filter...didn't they realize it would cause me problems? <Apparently they didn't know'¦or did not care.> I really have kinda amazed out what I can afford to put into this tank. We just bought a new house which is becoming more of a strain on cash. Would simply going to a less powerful Mag pump be the key to my solution here? <It will solve the overflowing problem, though you will lose that potential for flow.> If so what should I look for. <Something that pumps around 600 gph or less at your head height. Maybe a Mag 7 or possibly 9 throttled back a little.> I have a protein skimmer that does 250 gallons per hour inside the sump and a Magnum hang on the back canister (which I love because the current it puts out is soooo nice and it is easily cleaned every 2 weeks). Plus I have some internal pumps to move water and help with circulation. <Good.> My fish population is very low and will not increase. (Lunar wrasse 8 inches, Rock beauty 5 inches, twin spot hog fish 4 inches, and a true percula clown plus a host of corals). <I would consider this on the more heavily stocked side for a 75 gal.> Also how do I go about leveling this tank? It has over 150 pound s of live rock, 150 pounds of live sand and is filled with water! (AHHH) What does that unlevelness mean for the working state of the filtration? <It is more an issue of safety. If the tank is too far out of level it can put undue stress on the glass in ways the tank is not designed to handle. A tank can take this to a point, it is better to just ensure it is level. See the link at the bottom for info on how and why to do this.> Thank you very much for all of your help. <You are welcome.> PS I really do not think I could put another CPR on the back of the tank...with all the pipe work and the protein skimmer being inside the sump I just do not think that I have room. It is hard enough to maneuver the protein skimmer it barely fits inside the tank stand. Thank you again for your help. <Understood'¦the pain of finding space in a reef tank! You will simply need to reduce your flow if you cannot add more draining capacity. Good luck, Scott V.> http://wetwebmedia.com/aqstdleveling.htm

AWFUL bulkhead gurgling. Overflow Gurgling 2/11/08 Greetings gang! <Wuf.> I am having an awful issue with gurgling. After a fun-filled weekend of trying to get my 65 gallon tank drilled (read sarcasm in this), I FINALLY got it done. <It is what counts!> I have 2-1" bulkheads installed, with a Mag 7 in sump. The return line is "T'ed" off into 2 loc-line outputs. The new setup looks a TON better than the previous clunky clear overflow box I was using, BUT I am having one last issue with it (go figure). <Growing pains.> My drain lines gurgle. And gurgle. And gurgle. No stopping it. And it's driving me NUTS. To be honest, I can't even leave it running for the fear of angering my neighbor. Yes, it's THAT loud. <Is it gurgling or flushing?> I know the air getting sucked into the vortex going into the tube is causing it, but I cannot get it to stop to save my life. I've shoved a piece of airline tubing in it to try and 'break up' the vortex, but obviously it didn't work (otherwise, I wouldn't be writing this!). Any suggestions would be great. I would like to be able to sleep without having to use ear muffs. :-( -wuf <Two things can cause gurgling/flushing noises. First is if the intake of the drain is exposed to the atmosphere. This will cause the noise of the water traveling through the line itself to be heard. This is why you see the PVC elbows pointing down on most overflows. The other is a siphon or partial siphon in the drain line. This will cause all sorts of noises, some sporadically. You will need to drill the PVC drain intake at the point that it starts going down to your sump for the airline tubing (I would actually get a bit larger tubing for this). Be sure to drill it to fit fairly snug. From this point you will want to slide the tubing up and down until you find a point at which it will eliminate this siphon effect. Good Luck, Scott V.>

Bulkhead leak 2/2/08   2/3/08 My 4 year old tank has a small drip coming from one of the bulkheads. <Uh-oh.> All-Glass tank with built-in overflows, using their own brand of overflow parts (stock stuff, nothing customized). How do I fix this? <If it has gone four years and all of a sudden started leaking you likely need a new bulkhead (could be cracked) or at least gasket.> Do I need to drain the entire 125 gallons to repair? <No, you should be able to drain it below the top of the overflow box, drain the overflow and then replace the bulkhead/gasket. Good luck, Scott V.>

Overflow Issues'¦Sluggish Drain Lines -- 09/30/07 I just recently moved and set up my 125 Gal. tank with a 29 Gal. refugium. <<Neat>> About a week after having it all run smoothly, the tank has started overflowing. <<Uh-oh>> I have two Durso Standpipes on opposite corners of the tank using 1" piping. The two overflows were joined at a T-fitting, which led to a ball valve, then a 45 degree coupling at the end, which is about 3-4 inches below the top of the water line of the overflow section of the refugium/sump. <<Mmm, I see'¦having the two drain outlets conjoin at the ' T ' reduces the overall drain capacity of the pair as you have reduced all to a 'single' one-inch drain from that point on>> I have a Pentair Quiet One 3000 (780 GPH) running the return line on 3/4" piping. After it started overflowing the tank yesterday, I re-plumbed the overflow to allow both lines to run independently into the sump at about the same depth in the sump. <<Ah, good>> This didn't seem to have much effect. <<Hmm'¦something else must be amiss. After subsequent head-loss, I would expect the flow rate of your stated pump to be fine for the two 1' drains (figure a maximum of 300gph per drain)>> So, I tried to silicone the vent holes on the top of the end caps, which kept the overflow from draining at all. <<Yes, an escape route for the entrained air is a necessity. You might even try some experimentation with inserting differing lengths of rigid tubing in to these vent holes to see if you can find where the air is trapped/building and thus most efficiently expelled/released, allowing more water down the drain>> So, I gradually enlarged the vent holes. I noticed that one end (the end that is closest to the overflow section of the sump and flows nearly straight downward into it.) has a smaller vent hole, and drains at a much slower rate than the other end. <<Hmm, sounds like maybe the designer of the system was trying to 'balance' the flow rates between the two drains'¦which would only be possible by limiting the flow in one, thus reducing the overall rate even further (less than the 600gph max stated earlier)>> Could I have a snail impeding the flow that severely on that one end? <<Is a possibility, yes>> And if so, how do I convince it to get out? <<It will likely require disassembly of the standpipe or 'poking' it out with some type of flexible instrument (semi-rigid plastic tubing)>> Or is it more likely that my plumbing skills really suck? <<Hard to say without more information on your plumbing configuration. But try removing the standpipes and see how the tank drains'¦if you're lucky, any re-engineering may just be limited to these>> Any suggestions you have are greatly appreciated. <<It may well be that your plumbing design/configuration limits the drain capacity of these outlets more than realized. Once you determine there are no blockages (snails) in the lines, install a gate-valve on the output side of the pump and adjust the to where the drains can handle the flow and see if this is suitable'¦a flow of only a few hundred gallons per hour through the refugium should still be fine>> Thank you, Jules (Portland, Oregon) <<Happy to share. EricR (Columbia, SC)>> <Bigger drain lines... RMF>

Corner Overflow Modification 9/12/07 I have a 90 gal and in the process of starting it over since I had a problem with algae. The corner overflow acts like a tomb for crabs when they crawl up the overflow and fall down and in between. They die or something, trapped with no escape.... <Mmm, how can they crawl up the overflow, are they from the Batman family?:)> I want to cut these baffle slits out with a Dremel and if I ever do add fish I can stuff rolled up fine mesh to prevent the fish from up drafting. The sump is equipped with a bag filter so any critters are easily removed on bag replacement and placed back. Would it hurt to cut these slits out? Flow may even improve. <Shouldn't hurt any. I cut a few of mine out to improve flow. James (Salty Dog)> The aquarium is well out of its warranty so that's moot.

Rescue fish trapped in corner overflow  8/21/07 Hello. I have three small fish (blue Chromis, percula clown, and small blue hippo tang) trapped in the right? <???> overflow? of my 180g dual overflow tank. The intake and return pipes in the overflow ?make it very difficult to net them. I would like to rescue them and? keep them alive. They swim to the top every once in a while, but I've failed in my attempts to get them. Any suggestions? Can I flood the overflow to force the water over the top? Thank you, Sol W. <Turn off, drain the part of the system and net back into the main tank? Screen? the intake? Bob Fenner?>

Re: rescue fish trapped in corner overflow -- 08/21/07 Thank you for your quick response. My other question is that when I drain part of the system, and refill the main tank, should my return pump be off or on, since i am trying to force water over the top of the overflow back into the tank, and hopefully the three fish along with it?? <Mmm, my friend... you need to turn all off, drain this line, and remove these fishes... possibly with just your wet hand. RMF>

Mis-Balanced Overflows/Closed-Loop -- 07/02/07 Hello! <<Howdy>> I have a RIO 2100 that was in my Miracle wet-dry that I replaced with a Mag 7. <<Okay>> I went to put the RIO back in the wet dry/sump, (no bio balls) and the water overflowed in my tank. <<This was in a addition to the Mag-Drive pump?'¦overwhelmed the overflow drain>> Ok I shut it off went out bought an intake hose and box cause I figured there wasn't enough water to the sump. <<Siphon overflows, eh? Always a good idea to have more than one>> So I set up the extra intake for the sump and now the sump over flows. <<Something doesn't make sense here. It doesn't matter how many overflow drains you have on the tank, the total volume 'drained' to the sump won't exceed the volume of water being pushed to the tank by the return pumps. With the pumps off, the sump should hold the transient water volume without overflowing (if not, the working water height in the sump is too high, the overflow boxes in the tank are positioned too low, or likely a combination of the two). This is the 'static' water level within the sump. When you turn the pumps on, the water level in the sump should fall until enough water is pumped to the tank overflows to drain back down to the sump at the same rate it is being pumped. At this point the water level in the sump is at its 'working' height. If this is too low (i.e. -- the pumps are sucking air/causing bubbles), merely adding more water to the sump will cause the sump to overflow when the pumps are off. You will need to experiment with the height of the skimmer boxes in the display tank to allow you to add more water to the sump to keep the pumps adequately submerged, but not overflow same when the pumps are off. You don't mention the dimensions of your sump, but another possibility here is that this vessel is merely too 'shallow' for its intended purpose>> All I want is to get rid of the dumb power head in the tank and use my RIO 2100 to pump from a closed-loop to circulate. <<Mmm, do you understand what a closed-loop really is? Please read here and among the links in blue: http://www.wetwebmedia.com/pbretfaq3.htm>> Please help. <<Am trying'¦>> It's a 54 corner so I have limited room underneath but I even tried to use a bucket for the loop with pump to no avail. <<Understood, but what you are trying to achieve (closed-loop) will likely not be possible utilizing a siphon overflow>> Thanks <<Welcome. EricR>>

Need help with a tank stand--can't tighten bottom bulkheads due to wood center brace  6/20/07 Hi there, I'm hoping you can help me. I have a Perfecto 150-gallon glass aquarium whose dimensions are: 48" long, 24" wide and 30" tall. The tank has plastic center braces on the top and bottom. The stand for the tank is wood and supports it fully around all edges; the top is fully open but with a wood center brace running vertically through the center. Recently I had the tank sent out to an aquarium company to have the glass bottom drilled for two bulkheads along with an internal overflow box installed. I just got the tank back today, and they did a beautiful job. However, when the tank was set back on its stand, the wood center brace on the stand was too wide to allow me to fully tighten the bulkheads underneath. <Doh!> I asked the company who did the work what I could do to rectify this--they said I could notch a cutout in either side of the wood center brace to accommodate the bulkhead fittings. <Mmmm> However, I'm worried that this will compromise the integrity of the stand-- <Yes> I don't want it collapsing and spilling 150 gallons of water on the floor. Could you guys help me out as to what I should do--should I consult with an engineer first or is it okay to do this modification? Any advice would be greatly appreciated. Thank you. <Well... likely a "thinner" nut can be found... or the through-hull/bulkhead fitting reversed (with the throat up, perhaps shaved, cut down...) and an extra gasket found for both sides... and a smear of Silastic on both sides... that will do here... Perhaps with some shaving of the wood twixt the tank and stand to accommodate... If push comes to proverbial shove, you might need to consider adhering the (likely PVC) fitting directly onto the tanks glass... and dedicating yourself to never jarring it... Otherwise, the worst... giving up on the present holes, sealing over them (with glass panel/s and Silastic) and having the tank re-drilled. I agree with your NOT cutting through the manufactured stand support... UNLESS you feel comfortable (YOU!) with replacing this support (and losing the manufacturer's warrantee) with two new ones, placed on either side... Which is really what I'd do... Cheers, BobF>

Re: Need help with a tank stand--can't tighten bottom bulkheads due to wood center brace   6/21/07 Wow! Thanks so much, Bob, for your kind reply!! I really loved your book, by the way; it really helped me get started with my tank! Plus I've learned so much by reading through all the articles and FAQ's from WetWeb Media; you guys are great! I think I've come up with a plan for my stand. I'd really rather not mess around with the bulkheads; I only really need to notch the wood 1/4" on either side, but leave the center brace in place, and I think I'll place two new boards on either side, like you advised. I really don't want to have the tank re-drilled: it took the company forever to get the work done; I'd consider getting a new stand before doing that. Anyway, thank you so much, Bob, you've really helped me out! <Ah, good! Cheers, BobF>

Hang-On Overflow Noise (Water Volume vs. Pipe Diameter) -- 05/14/07 I just upgraded my 29 gal reef to a CPR100 overflow and draining into a 10 gal sump.  I decided to hard pipe the overflow in with 3/4pvc and two elbows.  No matter how I position the straight down tube into the sump sock I get the constant sucking and releasing sound in the box. <<You are likely trying to push too much water through the overflow.  The 1' bulkhead that comes with the overflow will only handle about 300gph (yeah, I know they are rated for more flow...just not practical), by reducing the output diameter to ¾' as you have done with the PVC pipe you have reduced the flow capacity even more to about 150gph or so...which is more than enough, by the way, for this tank/sump combination in my opinion>> Will the Durso pipe solve this problem of noise? <<I have seen what looks like a modified/compact version of the 'Stockman' standpipe for hang-on overflow boxes (see here:   http://www.aquariumlife.net/projects/diy-overflow/74.asp), but whether or not it will help is probably a matter of trial and error.  It may help smooth flow a bit but if you are getting a surge effect as you describe you will probably have to back off on the pump output from the sump (easily accomplished with a gate-valve plumbed in-line after the pump)>> Even if I put the sump pipe under water it still makes and ton of noise and I am really trying to understand this problem.  I want the tank to run with the least amount of noise as possible and the splashing in the sump will be easy to fix if I can get the overflow to stop sucking and making gurgling noises.  Any other suggestions? Thanks. Will <<Definitely sounds like a case of too much water volume coupled with a too small throughput diameter to me.  Regards, EricR>>

Over flow box: air bubbles break siphon  4/5/07 <Hi Brian, Mich with you today.> Please help! <Will try!> I can't find any specific solution to the tiny bubbles which break my siphon. <I think I may know what the problem is, but I have a couple of questions first.  Are you using a U tubes or do you have a continuous siphon overflow box?  Do you know where the air bubbles are coming from?  Do you know why you are getting air bubbles?  The attachment is not coming through.  Could you resend the photo?  It may be helpful in trouble shooting your problems.> I've looked at the provided links for hours and have also done many of my own searches, and still nothing.  Thanks for your time,      <Welcome!  -Mich>

Over flow box: air bubbles break syphon   4/2/07 Hey guys thanks for getting back so quickly with the questions!  I have an overflow box hooked up to my 45 gallon aquarium. It feeds to my 10 gallon refugium, and a mag-drive 5 pumps the water back to my aquarium.  To start off, yes,  I know I should have had my tank drilled.   My problem is that air bubles get sucked into the overflow box and gather at the top which eventually breaks the syphon (see picture attached). <Didn't come through>   I am required to keep sucking the air bubbles out using the air line tube attached to the top of the overflow box.  I have to do this every other day in order to keep it syphoning. <Dangerous... or at least annoying> The problem is that I work out of town on the weekends, and the syphon breaks every single time I leave.  I was wondering what I can do.  It would be cool if there was something that could let the gathered air bubbles out of the air line tube while not letting air get back in which would break the syphon.  I have tried inserting mesh into the overflow box's entrance (where the water comes into it form the tank).  When I do this I loose a lot of water flow speed and although the  bubbles stop, this is not the solution I am looking for.  I am also concerned with the lack of growth of the spaghetti Caulerpa  in my refugium.  I have 36 watt 50/50 compact fluorescent in my refugium which is on the opposite 12 hours as my main tank. I am ready to throw my refugium out my apartment window! Any help would be much appreciated.   Thanks you guys/girls are the best every time,  Brian- <Please read here: http://wetwebmedia.com/bubtroubfaqs.htm and the linked files above. Bob Fenner>

Re: over flow box: air bubbles break siphon  - 04/05/07 Sorry I don't know how to resize the attachment. <Still not getting the photo.  It is very strange.  The email is showing there is an attachment but there is no way to open the attachment.> To answer your questions so you can answer mine.   <A question for a question if you will...> I am using a continuous overflow box.   <I have used this also and I too experienced this problem> The bubbles are created when the water first enters the overflow box from the aquarium only when the water level of the water reservoir of the overflow box is lower than the level 1 which I marked on my attachment.  While the water level of the reservoir box is kept higher than the level 1 mark, the bubbles are not created.  The problem is keeping the water level of the reservoir of the overflow box higher than the level 1 mark using my ball valve and without overflowing my aquarium.  I can usually get the water level of the reservoir to stay at the level 1 mark for about a day, and then it slowly decreases.  I'm not sure why it doesn't seem that many people have the same problem as me because when I l search for  "bubbles and overflow box" the problems others have are different.  Maybe I am doing something wrong. Well obviously not right! <I think so. I'm not totally clear on how you have things set up, but I think I understand enough to offer some suggestions.  A couple of options.  You can get an "Air Lifter" pump and attach it via airline tubing to the knob.  This will continuously remove any air which gets stuck in the top of the overflow.  The pump sits on the top of the overflow and does not get submerged.  Or you can use a power head which has a venturi feature. Again connect it to the knob via airline tubing but the powerhead will need to be submerged in you tank.  Either of these will continuously remove any air build up and you should allow you to complete open you ball valve.  Does this make sense?  I have used the air lifter and have found them to last about a year.  I always kept a back up on hand.  When you start having a problem with circulation that you can't figure out, check the air lifter.  It might need to be replaced.  It may acts as if it is working, but I have found over time it looses suctioning ability.> Thanks again for all the help,      <Welcome! Hope this helps!  -Mich>

Re: over flow box: air bubbles break siphon  - 04/05/07 <Hello again Brian, Mich here.> Awesome! You have cured my headache thank you.   <You are most welcome!> I did have a venturi powerhead so I tried to mess with it and couldn't figure out how to incorporate it with the overflow box, so I did a search online.  I came across a forum that said instead of using a venturi powerhead or an "air lifter" you can just attach airline tube to the top of the overflow box and start directly siphoning this to your sump/my refugium.  I did this and it works.  The air bubbles are forced to siphon down to my refugium.  I think this is great, but I'm wondering if this is safe (over fill proof).  As long as my tank is safe from loss of power, reverse siphoning from return pump line, and loss of siphoning from overflow box  It should be safe right?   Is there any concerns that you might have about this vs. the "air lifter" or venturi powerhead.   <My biggest concern was the airline coming out of the sump and siphoning several gallons of water onto the floor.  Also complicating the matter for me, was airline tubing looks way too much like a kitty toy.  In my house this was way too tempting.  You may be OK if there are no four-legged critters or little two-legged ones!>    Thanks again,    <Welcome!  -Mich> Brian AGA Megaflow Overflow Boxes   2/20/07 Dear Crew, <Hey Phil, JustinN with you today.> I've looked everywhere and even called AGA and got stonewalled. I need to make some modifications to my overflow boxes and need to know what specific plastic they are made of. AGA tells me it's proprietary information. They look and feel like ABS though. Does anybody know for sure? Thanks for all your help! Phil Mitchell <While I don't work for AGA, nor have prior knowledge other than what I've seen in a consumer realm (as in, I've never been to their factory floor), I can say with about 95% certainty this is simply black ABS plastic, as you state. I'm a little surprised AGA is calling it a trade secret, actually. Perhaps this is simply to discourage modification of the original product and voiding of warranty? Hope this helps you! -JustinN>

Overflow Crack ?  12/20/06 Greetings WWM. Am very excited to be mailing the gods of aquaria. <"Always thought I'd be an apostle/disciple"... in my best Superstar voice...> Lots of info here - please let me know your feelings ... <It's very pleasant, warm down here visiting in FLA... and I'd really like a cool beer... oh, that's not what you were hoping for> thanks. Got a reef ready for fresh water Glasscages 55x23x28 inside-water = 150 net gal with a modified, (w/lotsa work), 45 gal "pre-made" Glasscages acrylic sump to a wet-dry. Did my homework, it's been three months of work, used sched 80, silicone and glue in all the right places. It is on the main floor, 3/4 in. Brazilian mahogany, over a weight bearing wall, finished basement below - usa homeowners insurance no coverage (unless vandals/fire/nature).? Any recommend? <Mmm, call your agent here re coverage itself> Used double felt on floor under oversized 5/8 in. plywood foot under modified, (w/lotsa work), wood cabinet carefully leveled/flat with linoleum, (felt allows easy sliding everything without water-nice). <Good tip> Used 3/4 in. pink foam (as per Glasscages 90 day warr) and linoleum between stand and tank, to make flat/level. The tank, (very euro braced), is very flat/level all four sides, with or without water, as measured on the top plastic trim and/or glass. Top of water to inside bottom of euro glass is 1 1/8 in. all four corners. Have two center-end, three-side 7x10x29 in. overflows with two 1 1/2 + 1 in. bulkheads ea. <Mmm, wish these were larger inside diameter... even if fewer in number> Tank glass is 1/2 in, overflows and euro brace surrounding the bottoms of overflows, etc is 3/8 in. Used 1 1/2 in deep half in. Mex Beach grey-black pea gravel - beautiful.? Is it ok? <For?> Have had water in it for two months. Ultimately did the fish free cycle thing with 2-5 ppm ammonia (Ace Janitor Ammonia - comes @ 10% strength) 1 tbs at a time until nitrate spike. <Mmm, such exogenous ammonia can be made to be of use...> Took three weeks and worked great. Three ppm ammonia vanishes in two days now. Am planning to get all the fish together from the distributor in one visit, via the best LFS, (fish will never be in the LFS tanks, they recommended this - sounded good), and put them all in at one time, (after major water change).? Think this will work? <Mmm, possibly... hopefully no, little nitrogenous, other cycling issues... You're doing this to lessen the chances of agonistic behavior? To save time, money on freight? What re quarantine procedures?> ... so ... After six weeks of water, the side of an overflow cracked from the bottom outside corner, where the tank bottom meets the side, up 10 inches at a 45 degree angle, towards the center of the tank, across the whole width of the side of the overflow. The overflow trickle leaks into the overflow only, at the crack, when empty. There is no outside leak. This means if there is a power failure, the 29 in high homemade 1 1/2 in. Durso standpipe will drain the tank down about five inches from top, (to the bottom of the inverted trap/street L), overflowing the wet dry sump by maybe 20 gals. The Glasscages recommends drain, cut out the caulking ... silicone a glass patch to the inside or outside of the cracked pane, and re-caulk. <Yes... this is what I would do as well> They say this normally happens because of homeowner leveling/flattening problems. Wish I could find an angle off on this stuff so I could correct it and have more confidence.? <Mmm, floors under load are often different then when tanks are empty... a good idea to fashion something... at least a piece of plywood under all to even all out a bit... better to make a more standard support (two plus by...) and set the tank/stand on this... But, it may well be that an investment in a structural engineer is in your future here.... See your "Yellow Pages"...> Am hopeful it was just a glitch, like a pre-existing crack/chip, or glass measurements/tolerances off, or forgot/didn't put enough silicone under that piece - oops. Is this a coin flipper, or what do you guys think? <Glass Cages make good products in my estimation... Impossible to tell re all the work from here> Will wait for your wisdom before I do anything ... and ... I have a fish dream. <"Brothers and sisters"> Am starting them together as juvenile's. 5 veil angels, 8 boesemanni rainbows, 8 Congo's, 5 clown loaches, 3 Bala's(-or-3 tinfoil barbs), 1 gold Severum, 1 stripe headstander, 1 red hook silver dollar, and 3 Siamese algae eaters.? Is this a good load for my 175 net gals? How would you modify? <Mmm... well... I'd settle on either a more calm (centering on the Angels) or brisk (Tinfoils and Red hook) mix/theme here...> ... aanndd ... Am planning a battery back-up to run an air stone. Could you recommend a comparable/ better air pump than the super Luft 38 - 22w (also, to put in the cabinet to keep the moisture down, and run a stone with a one way check valve)? <There is no better choice IMO> ... Is there a comp/better heater than a won bro titanium pro? ... Is there a recommended battery air pump? ... Mucho Thanks for your help, Andy <I do like this heater... Bob Fenner>

Air Bubbles in MegaFlow Return - 12/08/06 Hello, <<Howdy>> You have a great website! <<Thank you>> Q:  I bought a 95-Wave Aquarium from All-Glass Aquarium.  The system came with the All-Glass Aquariums MegaFlow Overflow Accessory Kit.  After I start the system everything is working fine but I noticed that the system was pumping small air bubbles into the tank.  After a while I realize that the "3/4" elbow" has a little hole that is placed on purpose. <<To stop back-siphoning when the pump/power is off, yes>> This small hole is an anti-siphon feature in the event of a power outage. <<Ah...I should read ahead *grin*>> When I close (using my finger) the little hole the bubbles will stop. <<Try positioning the outlet pipe such that the "hole" is "just below" the surface of the water.  This should stop it from entraining air with the water stream>> I have seen these systems working in other aquariums and it seems to work fine, (no air bubbles). <<Likely the outflow pipe was positioned as I described>> Can you help me realize what is wrong with the ¾ elbow? <<Give my suggestion a try.  If it is not possible to position the "hole" below the water line, then block the hole and position the pipe outlet shallow enough that the sump can handle the transient water in the event of a power outage>> Best regards, Luis Miguel Ferrero <<Cheers mate, Eric Russell>>

Re: Air Bubbles in MegaFlow Return - 12/11/06 Howdy Eric, <<Hello Luis>> I did what you recommended me and everything is working fine. <<Ahh, very good to hear>> Thanks! <<You're quite welcome>> Nevertheless, the weekend I reviewed other systems that utilize the same Overflow and notice that although the water level did not cover the small orifice it wasn't throwing air bubbles into the tank. (?) <<Hmm...perhaps those systems are utilizing smaller pumps/less powerful flow...or maybe the holes were "plugged">> Rgds. Luis Miguel Ferrero <<Cheers, EricR>> A possible Solution to noisy Overflows... not likely a good trade-off   4/26/06 Hi There, <Howdy> Not a question but maybe a solution.  I frequently see queries relating to noisy overflows and having spent months trying to solve such a problem would like to share my solution.   <Good> My setup is 50 Gallon tank with a siphon overflow box.  I could not get any substantial flow rate without a lot of noise, gurgling and air.  I tried aspirating with airline which made a small difference.  I installed an aquasilencer which is basically a modification of a Durso standpipe for a siphon box, again with some reduction in noise.  However I was still not achieving the rate of flow I wanted. By decreasing pump output you will reach a point where almost all noise disappears but this will be at a less than desirable flow rate, particularly if you are trying to run a Miracle Mud sump for which Ecosystem recommend up to 15 times turnover.  Consider this flow rate the "quiet flow rate" My solution;  Increase output from the pump to as much as the overflow will deal with; ignore the noise and bubbles for now.  You now have the maximum flow rate the overflow can handle.   <...> Take a length of 3/8 or 1/2 inch tubing and run it from the overflow box to the sump and start a siphon.  This siphon is silent.  You may need a second piece or a wider bore tube.  Basically you want the tube to carry the difference between the "quiet flow rate" and "maximum flow rate".  If the tube blocks or loses siphon there is no risk of flooding as the main overflow can handle the total flow rate albeit noisily, and you'll know as soon as you enter the room that something is up. <... what if the pump quits for whatever reason? The siphon will drain the tank to the siphon intake depth... overflow the sump...> It may not be a conventional solution and I have not seen it recommended on WWM before but it turned a noisy intrusive marriage wrecker into a soothing trickle in the corner, so worth a go! David <... I'd think this over a bit... Bob Fenner>

Re: A possible Solution to noisy Overflows   4/26/06 Hi Bob, <David> No , the siphon tube cannot empty the tank as it is draining from the overflow box <Oh... thank you for this> so depending on the size of the box it can only move a few litres to the sump. In a "self-starting" style siphon overflow box ,if the end of the tube is kept above the level of the bottom of the primary siphon tube the unit will not "lose" it's ability to restart in the case of a power outage. <I see/understand. Mis-read> I have this up and running and cannot find a logical flaw in the process.. however there is always someone out there who will and I'd be happy to deal with it. David <Does seem/read as a worthwhile "work-around"... though it would be better to aspirate the existing drain line/s from the overflow or increase this... or add another... or drill the tank... Bob Fenner>

Re: A possible Solution to noisy Overflows  - 04/26/06 Hi Bob, <David> Yes, I agree, drilling the tank would be the best option but not one available to me.  Of the MANY lessons I have learned from setting up this small tank, in advance of my "ideal" tank, one is that you cannot have enough overflows and in fact am looking at the possibility of incorporating a full length weir flowing directly into the sump in my next tank. <Neat> I have tried aspirating the overflow but the results are nowhere near as impressive as the additional siphon. <Thank you for this additional input> Keep up the good work. David <Am trying! BobF> 180 AGA with twin overflows question  - 05/19/2006 Hello WWM Crew, Love your site.  Your FAQs are always the first place I look when I have aquarium questions, and I couldn't seem to find the answer to the issue I am facing with my brand new 180gal (6'x2'x2') AGA with twin Mega-Flow overflows and an AGA Model 4 Sump.   The tank is built into the wall in my basement, on a DIY stand made from 4x4s, 2x4s, plywood, and carriage bolts.  The concrete basement floor is not level, but I purchased a 4' carpenter's level to help me with properly leveling the aquarium.  I spent the better part of an afternoon leveling, filling, draining, shimming, and re-leveling the aquarium until I've reached the point where I am satisfied that the tank is level.  The bubble is inside the lines no matter where I place the carpenter's level on top of the aquarium.     Here comes my problem, I fill the tank up and the water spills over the overflow boxes, but the left overflow box seems to fill up faster than the right overflow box.  Does this mean that my tank is still not level?  It took the right overflow box almost another full minute to fill to the point where the water drained down the Durso standpipe into the sump.   Could this be an issue with the way my tank was manufactured, as in maybe one overflow box was off by a few MMs when it was assembled/siliconed? Or is it more likely that my tank is still not "perfectly" level?  Is this something that I should be concerned about?  Will this reduce my flow significantly out of the right overflow box into the sump? Any thoughts you may have are greatly appreciated. Thanks, Dave <<Dave:  I have the same tank on a stand.  While I don't have stand pipes, my overflows seem to drain about the same.  It could also be the height of the teeth at the top is different or the number of teeth on one side versus the other.  If you are convinced that your tank is level (you might want a second opinion from someone else to make sure), then everything will probably be OK.  Another test of whether it is level or not might be performed by measuring the height of the water to the top of the tank with a ruler around various points.  If it's the same, you're probably level.  Best of luck,  Roy>>

Overflow Not Skimming - 07/04/06 Hey Crew- <<Hey Brenton!>> It's been a while so I guess that's a good thing!! <<Hee!>> I have a 100G reef and a 55G refugium tank going into a wet/dry box.  In my 100G the skimmer box/overflow works great, but the setup with the 55G tank's skimmer box/overflow doesn't work as well as it should. <<Hmm...perhaps due to decreased flow vs. the display?>> It seems that I can't get the water level inside the skimmer box low enough for the surface tension to be broken before going out through the U-tube. <<...?>> If I look at the surface of the water from underneath I can see what looks like an oil slick covering the entire surface, except for a little area where my return U-tube is located. <<But this "slick" is only in the skimmer box, not on the surface of the refugium, yes?  Little concern if so...is being mixed/drawn out>> The water level in my 55G is only 1/4" higher than the level in the skimmer box.  The difference in my 100G tank is almost 3". <<Differences in flow rates>> I have a Model 7 pump feeding the 100G (1" overflow tube) and a Model 3 (350 GPH) going to the 55G (1" and a 3/4" overflow tube, yes 2 tubes at once).  Without the 2 overflow tubes the skimmer box "floods", meaning the water level of the tank equals that of the skimmer box. <<Mmm...obviously the siphon on the display is much more efficient than those on the 'fuge.  Perhaps studying these will reveal the problem>> Is this pump too powerful for the amount of water in the tank? <<Has nothing to do with the size of the tank...my guess is it's a function of the position of the refugium (height above the sump) and the design efficiency of the plumbing...or lack thereof <grin> >> With the DSB I think I only added 25-30G of actual water. <<Shouldn't matter, the 1" pipe should be able to easily drain the input from the 350 gph pump>> When I bought the pump I didn't take the reduced volume of water into account, and now think I should have gone with the Model 2 (250 GPH).  Any ideas on how I can remedy this problem? <<Look to the plumbing, see if you're trapping air somewhere.  I really don't feel it's a matter of "pump" size>> Thanks as always. Brenton, San Francisco <<Always welcome, EricR...in MUGGY South Carolina

Water Noise vs. Flow Rates - 06/30/06 Hi! I am looking for a solution to eliminate noise from the overflow. <<A very common venture>> I tried everything and I started to believe a silent overflow is a myth. <<Hee! Indeed!  At least at the "higher" flow rates>> Now there is a way and it would be to dramatically reduce the flow rate. <<This is what I always advocate.  There are other things you can do to help...such as aspirating the return lines, submerging/adding ells to the termination ends, etc. ...but reducing flow probably makes the single largest difference.  Few hobbyists (if any) need to push 1500gph or more through their sump.  Much easier to deal with a sub- 1000gph flow rate here...employing other methods for increased flow in the display as/if necessary>> I have reached the point where it's either that or get rid of the sump and install an external skimmer. <<Mmm, let's work on quieting that overflow...>> Right now the skimmer is in the 1st chamber of the sump.  There is already good circulation in the display (15X per hour) from 2 Tunze Stream 6100 with a multicontroller. <<Excellent!  Reducing flow through the overflow/sump should not be an issue then>> I do a 5% weekly water change.  Most of the sump (25 gal) is in fact a fuge for plankton/pod production and macro-algae. <<All the more reason to keep it>> Display is 90 gal reef with 150lbs Fiji LR and sugar fine 5" DSB.  In these circumstances do you see any long term problems involved in having a flow rate from the return pump of only 6X per day instead of 6X per hour? <<Mmm...if I understand you, this would equate to just over 20gph (540gph divided by 24hrs).  This is slower than I like, but I think a flow rate of 200gph-300gph would be fine...and easily dealt with/made quiet>> If I may ask at the same time a bioload question. <<Sure>> I am thinking of some change and would like to know if this is too many fish. <<Okay>> Is this a heavy bioload with my set-up, would I be on the edge? : -2 Ocellaris -5 to 7 Chromis viridis -1 clown goby (Gobiodon histrio) -1 mandarin -1 Tailspot blenny (genus Ecsenius) -1 yellow tang (Z. flavescens) <<This would indeed fill you up.  I would like to suggest you forego the mandarin.  This tank isn't really large enough (refugium or not) in my opinion to be able to provide the necessary nutritional needs for this fish for the long term.  I would also suggest you keep the number of Chromis to 5, until you see what (if any) behavioral/environmental issues develop>> Lastly, would an Ecsenius blenny (like the Tailspot) be helpful to control Caulerpa growth in the display? <<I doubt it...the Combtooth blennies are more "filamentous" algae feeders.  The tang will probably be more useful for this purpose, though there's no guarantee of that either>> And what about a tuxedo blue urchin (Mespilia globulus) for that same purpose? <<A neat critter...and likely a worthwhile addition...but it too will probably go for your hair, and most assuredly your coralline, algae first.  You best bet re removal of the Caulerpa is manual extraction.  If you can manual reduce it enough, the tang might be able to keep it in check for you.  I guess you'll know better than to add this to your display next time, eh! <grin> >> Many many thanks! Dominique <<Quite welcome.  Regards, EricR>>

Re: Water Noise vs. Flow Rates    7/1/06 Thanks Eric! <<You're very welcome Dominique>> The Caulerpa I didn't add to the display and not even to the fuge as I am using Chaetomorpha and red Gracilaria instead. <<Ah yes, much better choices in my opinion.  I utilize Chaetomorpha in my refugium myself>> It just appeared there uninvited and in two species. <<Hate it when that happens...>> Regarding the mandarin I have to say I kept one for 7 months and it was still fat, but it jumped out of the tank. <<Hmm, I've never known/heard these fish to be jumpers.  Would make me think environmental conditions/tank mates were not suitable for it...possibly. Please don't misunderstand my tone here <grin>, but the vast majority of these fish "slowly" starve to death within twelve months.  There's always exceptions, and of course those few dedicated hobbyists (maybe you're one of these!) that strive to provide suitable care/environments for these fish...but for the majority of folks, Synchiropus species are best left in the ocean.  If you're determined/dedicated to keeping this fish, please research all you can re their care/husbandry on our site and the net in general>> This made me place a net in an anodized aluminum frame over the top of the tank so it won't ever happen again.  So to summarize your answer: bioload should be ok (I won't get more than 5 Chromis) and even thought it's not ideal I should not have problems with the 20gph flow rate. <<Indeed...a couple hundred gallons per hour at least.  If noise is still an issue, do write back and I'll gladly address this with you further>> Thanks again! Dominique <<Cheers my friend, EricR>>

Equipment...Tank Modification   8/19/06 Hey guys/gals... <Hello Dave> This may be my fastest question yet... <And, my fastest answer.> and I'm pretty sure you don't have anything posted on your resources. I have a pretty standard 90 gallon that's been running for 4yrs.  I want to start getting into corals and am taking the necessary steps to accommodate them.  I bought a Tunze Wavebox thinking that the massive yet gentle flow back and forth would be great for the corals... <Is> however, my corner overflow in the tank was built a touch too high.  I have about 2cm of room between the water top and the lip of the top border around the tank.  Tunze recommends a MINIMUM of 5cm.  I don't want to drain the tank and have the overflow ripped out.  The plastic (or whatever it is) border on the top that includes the lip for which to place the glass covers (do u <you> know what I am talking about?)... <Yes> from what I've seen, most tanks have them.   Can this be easily knocked off the top or removed?? <If you are talking about the black/oak trim on the top of the tank, <<Is not... is talking re the inside structure for the tank's overflow... if plastic of some sort this can be cut, though not easily... I would drain the tank to do this... many bits of plastic otherwise... RMF>>  (glass tank I presume??) this small lip that supports the glass can be removed to accommodate the space the wavemaker needs. Is this is what you have in mind?  Have you ever heard of anyone building more height onto their tank? <No, not safely.> I'd like another inch or inch and a half.  Note, the water level would never be higher than the original sturdy glass... the extra inch or so of glass would merely serve as to accommodate the little 5cm water movement from the wave.  Any suggestions, comments, advice?? <I'd contact Tunze with the above question, get some input from them.   http://www.tunze.com/117.html?C=US&L=1> If not... would a Tunze Wavebox have any outstanding benefit in a fish only predator tank of 200 gallons? <Yes, very beneficial.  Will help keep detritus/waste suspended for more efficient removal from the tank.  Also has a cleansing effect on the rocks, corals, etc.  James (Salty Dog)> Dave

Overflow Noise/Glass Scratches - 08/15/06 Hi, <<Hello!>> I have a 54G RR Corner tank with a 1" drain and a 3/4" return. <<Sadly undersized throughputs...even on this volume of water>> I bought the whole reef set up used, but I can't imagine how the previous owner tolerated the noise! <<Mmm, indeed...you can't really put much water through a 1" drain before it becomes problematic>> I installed a 1.25" Durso standpipe (1" did not work, now I follow directions, doh!).  I have a 1/8" drilled hole in the top of the T of the Durso.  It was fascinating to watch the relationship between the air hole size, the drain line position relative to the sump water level, and the gurgling and flushing effect. <<Ah yes, you are finding out just how "fiddly" it can be.  I would like to suggest you try enlarging the hole just enough to push some airline tubing through and down in to the standpipe.  This will help with aspirating/releasing air from the drain line and often eases the gurgling sounds.  It will take some experimentation to determine the best length/diameter tubing to insert>> As I slowly increased the air hole from a pinhole up to 1/8", I observed the step by step decrease in flushing effect amplitude.   <<Yes...allowing that air I mentioned to escape more readily>> It started at about a 3-inch oscillation, at 1/8, it was gone completely.  Adjusting the drain pipe position also impacted the flushing effect and required small changes in the air hole.   <<Pretty much all comes down to eliminating the obstructions (air bubbles) to the water flow>>    OK, on to my questions:  I have extensive bubbling/gurgling noise in the sump from the drain. <<From air that is "carried" down the line by the water>> I have read on WWM two things to try: A "T" or "Y" fitting on the drain line, and aspirating the drain line from the top with air line tubing. <<Yes indeedy...though I prefer a 45- or 90-degree ell fitting on the end of the drain line>> I am confused about the specifics of both of these.  For the T or Y fitting, how is it positioned? <<Is of little consequence...just position to direct flow in the direction you desire>> I am guessing that it goes at the bottom of the drain line, with one leg submerged and one leg above the sump water level? <<Mmm, okay...I think I'm with you now.  The purpose of the fitting on the end of the drain line is to "slow" the rush of water a bit.  So...experiment with the position to determine which gives you best results.  Either way you position it, I find that having the end of the drain line completely submerged usually works best.  And do be aware, it is usually not practical to expect a 1" drain to flow more than about 300/350 gph without much hassle and noise, as you seem to be experiencing>> For the aspiration tubing, is the tube supposed to have its own hole separate from the existing air line in the Durso T cap? <<Refer to my earlier comments re>> Or does it simply go down the same hole? <<Yup!>> It also seems to me that the bubble/gurgle would be reduced if I had the water break on some live rock rubble or other irregular surface. <<Can give it a try>> I think I have seen reference to using filter pad material. <<A detritus trap>>   Next question: Even though I only have about a 2-inch drop from the overflow wall to the top of the water behind it, it still makes an annoying, trickle noise that induces the need to visit the bathroom at night (tank is in the bedroom). <<Hee!>> I am thinking of installing some kind of stepladder down to the surface.  Or perhaps a piece of filter pad would also suffice.  How have you seen this done? <<Raise the height of the standpipe to raise the surface of the water in the overflow...it only needs to "fall" a fraction of an inch or so>>    Last, the tank is used, and has a good number of extremely fine scratches that are visible depending on angle and lighting.  I have read that you generally shy away from glass polishing/buffing, but that usually seemed to be because the e-mailer was asking about significant/deep scratches.  What do you think about using a commercial buffer on an orbital drill pad, and follow with a thorough cleaning? <<I think you'll do one of two things...nothing at all...or make it worse.  Scratches in glass "can" be repaired/removed, but unless you really know what you're doing/have done this before, I recommend you refer to a professional for advice/consultation.  You may find it is easier/cheaper to replace the tank...or learn to ignore/accept the scratches>> Jack <<Regards, EricR>> Refugium Size/Overflow Surge/Skimmer Adjustment - 08/25/06 Hi Everyone, <<Hello Diana!>> I just installed a Refugium (it is 36"x18"x13" with the refugium being 15"x13" does that seem big enough for my tank?) on my 150 Gallon reef tank. <<Whether this is "big enough" is a question that can't really be answered...bigger the better as you are probably aware.  But the fact it is there "will" provide benefit to your system>> I have two pumps in my return (one for returning water straight back to the tank the other goes thru the chiller and UV light). Now here is my problem.......When I have both pumps running the overflow on one side of the tank is putting out air thru the hose back into the skimmer area. <<Is having problems handling the volume...efficiently>> It seems like the overflow pipe is filling up to fast with water and the air hole in the overflow pipe can't keep up so it creates suction.  Does this make sense? <<Sorta <grin>.  What's happening is the volume of water traveling through the pipe with both pumps running is trapping/preventing the air in the pipe from escaping efficiently.  This are is then pushed to the sump (the bubbles you see being created there) and/or building to the point that it surges back up the overflow pipe (intermittent rushing/flushing sounds)>> My question is how it comes that it only does it on one side and when both pumps are running (I guess I answered that one already since it is putting more water into the tank with both pumps on). <<Indeed>> Now my main question would be how I can fix this problem?  Any help would be appreciated as I would like to get my water flow going again and make my fishies and corals happy. <<The easiest solution would be to install gate-valves on the "output" side of the pumps and temper the flow down to what the overflow can quietly and efficiently handle.  Another approach is to "aspirate" the return line by inserting a length of small diameter tubing (exact diameter and length of insertion will require experimentation do determine optimum performance) to help with the escape of entrained air from the line.  This method will usually yield some improvement to water flow but is no panacea on its own and will probably work best if employed with the addition of the gate-valves as mentioned previously>> One other quick question, if you don't mind. <<Not at all...>> I just hooked up an ASM G2 Skimmer in my refugium and I was wondering if there is any hints on how to get it working just right (as of now I'm only getting greenish water)? <<Simple adjustment of the riser-pipe will change the concentration of the skimmate.  If the skimmate is too thin for your liking, adjusting the riser-pipe "down" will lower the water level in the skimmer body yielding a thicker skimmate... you will likely have to "play" with the adjustment a bit to find the desired height/skimmate production>> Thank You, Diana <<Quite welcome.  EricR>>

Overflow box problems  - 09/03/06 Help I have a 75 gallon vertical tank, octagon shaped.  I have a wet dry filtration system with a typical overflow box.  Every time I stick my hand into the tank to try and clean or feed my animals the overflow box stops working. <Too touchy for my comfort...> I know my hand and arm displace water but it is very frustrating to go through to process of restarting the wet dry circulation every time I put my arm in the tank. Any recommendations? Frustrated. <Yes... I'd add another overflow... Please read here: http://www.wetwebmedia.com/overfloboxfaqs.htm and the linked files above. Bob Fenner>

Overflow, flow, noise...  9/2/05 With a standard (AGA/Oceanic) one inch overflow (on a 90 gallon tank), would it be correct that about 300 gph is all that can be run through that (via a Durso) without the up/down flushing effect? <This is about it> I've found my Panworld 50PX (590 gph max) has to be ball-valved back probably about 50% to keep it quiet.  Wider diameter pipe before and after the hole really can't do much here, right (the Oceanic Durso is already upsized)? <Correct> The only answer I assume would be to have a larger hole which isn't going to be an option for me.  Still, heavy in-tank circulation can compensate for this low flow I presume.  Frankly, I'm not sure I'd want a heck of a lot more flow going through the sump.  I appears I'm going to have a hard enough time quieting the water noise from water crashing into the sump? <Possibly... there are a few approaches here: http://www.wetwebmedia.com/pbnoisefaqs.htm> Any clever ways to quiet the water flowing and crashing in the sump, other than say sinking the drain line and perhaps having a "T" below the water line in the sump to both smooth out the flow and break the one flow into many?  Like most folks, I'd like to make things as quite as humanly possible.    <I understand... Please see the link above. Bob Fenner>   

Overflow Covers?   3/3/06 Hello, I have a custom made Oceanic glass tank.  Approximate dimensions are 63"L x 28"W x 50"H. <! Wowzah... four plus feet tall? Mmm, maybe the stated W and H are mixed...> Do you know are there any companies or products out there that make covers for the overflow box. <I would check with the manufacturer here... or resolve to make these yourself (not hard to do...> In a tank this large I am having a hard time adequately covering or hiding the box.  Any suggestions? <Mmm, large stacked piles of rock decor... fashioning faux material to fit over/around... is this a marine system?> Do you recommend gluing any live rock to the box? <Good question, and no...> I really don't know where to go for ideas.  Thanks again for a great site and all of the great info.  You guys rock!!! Thanks, Skip <Check with Oceanic here for their suggestions, and please relate what they state back to us for sharing. Thank you, Bob Fenner>

Re: Overflow Covers?   3/4/06 Bob, Thanks for the reply.  The dimensions of the tank are correct.  It is closer to a square if you can imagines that look. <Ooof, I can. Glad I wasn't there for moving day!>   Anyway, I contacted Oceanic who recommended using epoxy to attach the rock to the cover. Why don't you like this idea?  I have been given this suggestion by several dealers now and am always curious to hear the other argument. <Mainly the lack of ease of changing this... not easy, practical to "bust off" later> Oceanic did give me the name of an individual in the Dallas area that does them (but it is quite pricey).  They also recommended that I call a company called Aquarium Design Group in the Houston area.  After some more searching on the web I did find that brand new this month, Living Color www.livingcolor.com, launched a new line of pre-formed overflow covers. <Oh?> 5 different styles to match your setup.  Actually pretty cool. <Sounds very good> I did speak with them and they can make customized versions, although the price was definitely getting up there.  I think I would rather put the money into other things for the tank.  Anyway hopes this helps. Will be interested to hear your answer on epoxy use on the overflow. Thanks again for all of the info. Take Care, Skip <Though it's a bunch of stacking... am still a fan of piled rock. Cheers, Bob Fenner> - Tank Modifications - Good evening/morning folks! <Morning here...> Have a quick one for you.  <Promise?>  I am buying a 200 GAL Glass tank with corner overflows. Unfortunately, as we all know, the pre-drilled overflows are too small (1" Overflow (2X) and 3/4" Return (2X)) drilled in the bottom corners in an overflow box.  I was wondering if it would be possible/feasible/advisable to cut a piece of glass to size, silicone the heck out of it and cover the holes and re-drill larger holes in the back wall at the water line.  Do you think this would hold?  <Yes.>  Or is it a good place for a leak to form?  <Should work fine... method has been used to repair tanks of all types. Don't be stingy with the silicone.> Was thinking about drilling (2X) 2" holes for Overflow for corner boxes and (2X) 1.5" holes for the return in the center back (am planning on also adding a manifold around the perimeter for extra flow/turbulence).  As always, you folks are the best! Don't know what we'd do without you! Tom (The Tool Man) <Cheers, J -- > 

Circulation Problems in a Reef Tank, Needs to Visit Conjunction/Punctuation Junction, too I am having a problem balancing the water flow [going] from [the] main tank to sump, [then] from sump to refuge [that is] above main tank, and [then back] from sump to main.  I have a 58 gallon tank. <Oh oh...> I drilled the back glass. I have 2-1" bulkheads about 4" up from bottom of tank in the center for drains. <Where?...!> I also have 2 -1" bulkheads drilled on the ends of the back glass. 1-about 4" from top of tank and the other about 6" up from the bottom of tank on both sides. <?!> I have a 5 gallon refuge which sits right at the top of the tank. On the refuge I have a 3/4 bulkhead for water return from sump. Then [I have] a 1" bulkhead for drain into main tank. I have a Euro- fill 180 30 gallon sump that set[s] under main tank. Inside main tank I have an overflow box 19" tall by 8' across 6" from front to back covering the 2 1' bulkheads. I have two Durso stand pipes connected to the 1" drains, going with 1 "1/4 pipe for the stand pipes. In the sump I have an ASM G1-X skimmer. For return pumps I have 2 Rio Hyper Flow 14 HF power heads; these pumps are rated at 840 gal [gph] at 1', 660 [gph] at 4'.  I have a 3/4 PVC pipe running up to the two discharges into main tank. The other pump is hard plumbed to the 3/4 bulkhead in [the] refuge. I also have a standpipe in refuge to drain back into main with a baffle where the discharge comes from sump. I tried this, but the force from the pump was really strong, causing a lot of bubbles in refuge and main tank, a lot of micro bubbles in main tank. Over all circulation was good, levels stayed even in all tanks, just a lot of micro bubbles.  I tried to split the return from pump in sump to refuge and have 1 discharge go to refuge, 1 to main tank, but because discharge is higher on refuge than [the] 1 going directly to main tank that water would go to [the] lowest discharge and would not then go to refuge also. I then tried using valves to regulate water flow between the 2 discharges, but when I did this my overflow box began the flushing effect, [the] system would not balance out. Still had micro bubbles in main tank. Went back to 1 discharge to refuge, cut the flow back with valve, still had flushing with drains plus strain on pump. [I] did see a reduction in micro bubbles in main tank. I tried using 1 pump from sump, micro bubbles almost gone but barely have any overflow, not sure if this is enough circulation for corals hard and soft.  For the 2 bulkheads on each side of [the] drains I made a close[d] loop on each one these, have a Mag 9.5 hook[ed] to a SCWD - one for surface, one SCWD for lower jet bulkheads. I do not know how to get rid of the micro bubbles [and] keep the same flow with the 2 Rio pumps, or if I need to for circulation [and] supply the refuge [to] keep it balanced with out the flushing and micro bubbles. I added a another baffle in sump right after [the] drain, before [the] skimmer, with 2 baffles after skimmer.  I really did not want to use sponges or filter socks. Any Help would be greatly thankful. Thanks Jeff. <Well, you have two issues... the circulation can be fixed only by re-drilling larger through-puts... unless you want to greatly reduce water flow... I would NOT have holes drilled near the bottom of tanks... as the consequences of power outage or pump failure from below will prove disastrous... Therefore I would silicone covers over these... The bubbles can be addressed by a few means... likely the best for you here is the use of Dacron "socks" over the discharge lines (below)... and baffles to provide air-free water to your pumps. Bob Fenner> 

Water Level Fluctuation in Overflow Dear Crew: <Paul> The water level in my overflow fluctuates by about an inch every 10 seconds. <... not large enough, water level/s too low... pump/s too large flow rate/s...> If the water level drops close to the opening of the Durso-type standpipe, an irritating suction sound is generated. <Yep> What can be causing this periodic fluctuation in water level? <See above> Why is the flow through the standpipe not constant? <Transit volume issue. Your water is "oscillating" twixt your system above and below... due to insufficient plumbing, and/or pumping flow> I have an Oceanic 75-gallon tank with a "Mega-Flow" overflow and an Oceanic standpipe that is similar in design to a Durso standpipe. The overflow empties into a 29-gallon refugium with an Iwaki MD-30RXT pump. I had replaced the Oceanic bulkheads with PVC connectors to increase the size of the openings by 1/4" and to increase the water flow. <Good move. You may still need to add water (take care to measure... with the power turned off... so as to avoid flooding) to the sump... reduce the flow rate of the pump... Bob Fenner>

Modify Reef Ready I have a 75 AGA reef ready tank, it currently has a 1" drain and a 3/4" return. <Dismally small fittings> I'm wanting to increase flow into my sump so I can use a Mag 24 (36 would be great but probably not possible.) to power a manifold with 7 tees. Thought I could use the 3/4" return as another drain to the sump with a Durso standpipe, so I would have a 3/4" and 1" drain. <Still way too insufficient... you need two- two inch drain lines... minimum here> Now, what can I do/needs to be done to maximize my reef ready overflow to max out my bulkhead drains (have been reading that the overflows don't work the best). I'll use the Mag in the sump. Currently have a velocity T4 external plumbed. Reason for the modify is I want to increase flow quite a bit but want to remove my powerheads and not add more... already been established for a few years so drilling for closed loop is out of question. Thought of using my return as a manifold. <... you need to rethink all this... either go with hang-on overflow boxes, or bite the proverbial bullet... drain the tank, have it re-drilled. You can read on WWM re... Bob Fenner> 

Re: Modify Reef Ready Turnover Hi Bob: <May the Force be with ye!> Thanks for the quick reply!! In keeping with all the hoopla...I'm having a Star Wars moment. Actually speaking with the Yoda of the hobby!! <Geez, and I can't get Di (wife) out to see Lucas' sixth and supposedly last in the series... And hey, I'm taller than two feet, and not quite as green I be> I think that I was unclear or I am misinterpreting your answer. I'll give it another try.... When I said the tank has 2 x 1" overflows, I was only referring to the lines to the sump. The tank has two separate corner overflows, each with 1" overflow and 1" return. <Ahh!> I'm not sure whether that was clear. Does this affect your response? <Indeed it does> I get the sense that you were saying that I may be able to get the flow close with the four holes, but re-drilling would be better. <Yes> Thanks again for the help. Take care, Greg. <Will endeavor to do I will. BobdaF> 

- Fish Overboard, Or At Least into the Overflow - There are postings in WWM about fish jumping into the overflow filter, but I have not found suggestions for how to get them out (without taking down the whole system). I have an Oceanic overflow trickle filter in an Oceanic 72 gallon fish/reef tank.  There is an extremely small gap between the cover glass and the rim of the overflow filter, too thin I would think for anything to jump through. However, I do remove the cover glass to clean it once in a while. Perhaps during one of those cleanings a Percula Clown made the leap into the overflow box. <I had a clownfish that would end up in the overflow of my 180 Oceanic all the time - once a day.> He is surviving (the last time I looked), apparently feeding off food that comes in through the three rows of drain holes at the top, middle, and near the bottom of the tank. The box has plumbing inside it, and the clever Clown hides beneath the plumbing whenever I look down the box with a flashlight.  I only catch glimpses of him.  Without the plumbing, I could use a long handled net and return him to the main tank.  However, even if he did not hide, I have difficulty moving a net in the free space.  Any suggestions short of taking the whole thing apart? <I actually used to catch mine with my bare hand as it was easier to do and almost impossible with a net. Move slow and be patient. After a while, my clownfish got used to it and when I reached my hand in there, would just stop swimming and let me catch it. Anyway, breaking down the overflow plumbing would be a pain... would do that as a last resort.> I've learned about plastic gutter guard and egg crate and will be installing that to prevent this from occurring again.  Also, I lost a Nudibranch to suction through the drain holes and am hoping that the gutter guard will prevent that from reoccurring.  Any pointers on where to find a design for installing the gutter guard and egg crate? <Probably just use nylon wire-ties... affix over the overflow.> I understand one is in BOCP1 but can't find it there. <Cheers, J -- >

- Fish Overboard, Or At Least into the Overflow, Follow-up - Thanks. <My pleasure.> It makes sense that it would be easier to catch it with the hand than with the net. Glad to know that others have had this problem; at least, I know that it is solvable. <Well... both: a rather common problem and also easily solved. Good luck catching your fish. Cheers, J -- >

Bulkhead - 07/01/05 actually transit volume in tank/sump... mis-matched Good day, <<Hello!>> Once again I have only one place to turn to for help. (Thanks again for all your support and advice). <<Our pleasure.>> I have been struggling with this for days, read a multitude of FAQ's and still can't figure out what I'm missing.  I'm busy setting up my new 150 gallon tank and I just can't figure out how to make the bulkhead overflows work properly. <<Okay?>> I have 2 x 1.5" (or 40mm) bulkhead fittings high up in the back wall of the tank.  On the inside of the tank nothing is connected (its just 2 holes with "tank connectors) <<Intake screens?>> and on the outside it's connected to 90-degree elbows which connect to the pipes going down to the sump. <<Sounds fine so far.>> <T's with their open ends open to the air would be better. RMF> The inside diameter of the bulkheads and all pipes is 40mm (or 1.5"). <<Good to hear...bigger the better.>> I was under the impression that these 2 simple holes in the tank will easily drain 1000gph, so for the return pump in my sump I bought something that pumps at 1000gph. <<Yes, I too would expect the pair to handle 1000gph.>> Now, when I switch on my pump in the sump, the following happens - as the water level rises, it starts flowing into the two drain holes an down into the sump. However, the draining starts slowly at first and only increases in tempo as the water level rises. <<Yes...takes some water pressure to overcome the air pressure in the lines.>> When the water level becomes high enough so that the overflow holes are about halfway submerged, the overflow starts matching the rate of the inflow from the pump.  The problem is, by this time the return chamber in my sump is empty and the pump starts sucking in air. <<Simple matter of your sump not being large enough my friend.  The sump should be big enough to hold a "working" level/quantity of water IN ADDITION TO the "drain-off" from the tank when the pump is off.>> Now unless I'm making a really stupid mistake somewhere it seems that with these bulkhead overflows you have to push quite a lot of water into the tank first before the overflow "kicks in". <<Laws of physics at work here.  You might ease/help things a bit by aspirating your return lines.>> Can you perhaps give some advice here ? How do you normally set up these bulkhead overflows?  I believe that the inside of the bulkhead is sometimes connected to an elbow that bends up, but unfortunately this is not an option for me (because the holes are quite high up on the tank wall).   <<A bottom drilled tank with overflow box "might" require less water volume to get things going due to rapid build up of water height (weight) in the overflow box...but you haven't done anything wrong here, you simply need a larger sump volume of water.>> Am I just missing some simple concept here or do I just need a much larger sump to cater for the initial "kick off" of the overflow (Really didn't think my sump was too small)? <<I think for this application your sump is too small.>> Your help will be very much appreciated. Thanks Chris <<Regards, Eric R.>>

Re: Bulkhead - 07/02/05 Thanks a lot Eric, I don't know where some of us would be without your help. <<Always a pleasure to assist <G>.>> Have a good weekend. <<And you too.>> Chris <<Eric R.>> Plumbing suggestions? 7/21/05 Greetings Bob and crew... <Sam> Suffice it to say that you guys have been quite helpful in the past, and continue to provide an incredibly valuable service to the hobby.  Thank you. <Welcome> I'm getting really tantalizingly close to being ready for live rock (happy dreams of LR critters poking around), and just have this one, last plumbing issue before all of my ducks are in a row.  Would like to see if I'm on the right track. <Sure> Here's what I've got.  125 gal tank.  1" drain, <Only one?> with a Durso standpipe.  The drain hits a T which routes water to the sump for processing, and also splits water to the refugium, which gravity feeds back into the sump. Return water is pushed back to the tank via an Iwaki 30RLT, which is linked to a SCWD, returning water alternately to two 3/4 inch returns.  All plumbing via vinyl tubing.  Limiting factors as I see them are the 1" bulkhead on the drain, and the 3/4 inch connections on the SCWD, necessitating 3/4 inch returns.  Additional current via a PanWorld 50 PX-X (1100gph) feeding a closed loop.   <I do wish... you had two 1 1/2" drains, two 1" returns...> Here's what's happening.  With about four extra inches of water in the sump to prime the system, I'm able to raise the water level enough that water is returning via the drain.  However, even as the water is returning from the tank, the pump is pulling enough water that the sump level is falling below the pump intake, resulting in lots of cavitation. <Trouble... drain lines too small, sump too little water for transit volume>   Looking at the 1" drain tubing, its not draining at the full capacity of the tubing, which is the same diameter as the opening in the bulkhead. <... a common misperception... the line doesn't "suck" water out of the tank... water has to "pile up" higher... drain> My first thought was that the pump was pushing more water than the drain was capable of handling. <In a manner of speaking, yes> I now am not convinced that this is the case. Considering the SCWD, the 90-degree fitting on the openings of the 3/4 inch returns (and the spring activated check valve) I've got something like 9 feet of head according to Reef Central. <The model there is necessarily a simplification>   Looking at the spec.s on the 30RLT, with that much head pressure, I shouldn't even be approaching 600gph, which I believe is somewhere in the area of the max capacity of the 1' bulkhead. <Uh... no... there are a few very important (co)factors involved... the vinyl tubing has some induced drag, the extent of the horizontal run from the bulkhead...> I'd considered slipping a gate/ball valve on the output of the return pump, but really don't think that's the answer. <It is not>   Perhaps I need a slightly larger hole in the cap of the standpipe?  Or perhaps just adding a few more gallons of water in the sump for the pump to prime the system? <No my friend... the root of the problem here is really the lack of size, number of through-puts... you won't be able to get enough water through what you have> This is my first foray into plumbing an admittedly rather intricate system, and as such, would be interested in any suggestions you could provide.  Am also curious if there might have been value in hard plumbing the system, <Yes... in some cases, some flexible is a good idea... but in most... rigid is preferable... for how many reasons?> as it seems like there might not have been as many issues utilizing straight lines and angles.  I assume that that the other side of that sword is that with the vinyl tubing, I likely have less head pressure than a similar set up using elbows. Thanks in advance, Sam King <Sam, do read over the Plumbing materials we have archived on WWM... there's a bunch. And do have some other folks with similar systems chat with you re yours... I would have the tank drilled for two 1 1/2" bulkheads (two inch diameter) and use the existing through-puts for returns. Bob Fenner... who has "been t/here, done this... many, many times>

Overflow Box 7/25/05 I am very new to this and I just decided to switch from a canister filter to a sump since my tank is not drilled I purchased an over flow box now I cannot make it work can you help me?? Bobbie Jo <Bobbie Jo, don't know what you are having trouble with.  I'm guessing you can't get the siphon started.  Need to fill the overflow box with water, put a flexible airline tube into the siphon at the very top of the curve, then suck the air out of the siphon tube and remove the air line.  Siphon should start working.  Also try and contact the manufacturer for help.  James (Salty Dog)>

Overflow Box 7/25/05 Thank you for the help I don't know why they don't send directions thanks again. <You're welcome. James (Salty Dog)> Bobbie Jo Overflow murders Perhaps you can help me out. I have a 125 Gallon salt water tank and just upgraded to an Amiracle sump filter but the overflow is sucking my smaller fish along with shrimp etc. Is there any method to prevent this? I've been to a couple of per shop in the local Jersey area but they don't offer any good suggestions. What can I do. Thanks very much.... Peter <if the overflow is an internal skimmer box then simply fill it with submerged bioballs. This will not impede water flow but will prevent air bubbles and fish from making it through. Kindly, Anthony>

U-tube overflow modification Hello, I use an overflow box with a u-tube. Every week it seems that I must re-siphon the u-tube, otherwise air enters the tube and tends to decrease water movement to the sump and increase the water inside the overflow box, causing less flow and less water movement. Is there any fix to prevent this? Thanks, Rob <the best solution is to not use an overflow at all... they hold you hostage in fear of the inevitable overflow from a siphon break... even the best designed ones can fail. Do have the tank drilled for a gravity overflow when you can. In the meantime, there are many DIY solutions on the net to help with this... simply do a keyword search with the pertinent terms. Also look on the DIY link at www.ozreef.org... I think a saw plans there for a better mousetrap. Essentially, what you need to do is drill a small hole at the top of the tube, glue a rigid airline stem in place and hook it up with the Venturi of a nearby powerhead. This Venturi will constantly siphon air bubbles that collect (with water) and prevent the siphon from breaking. Best regards, Anthony> Rob Cook

My crazy clowns (and overflow boxes) Mr. Fenner, I just wanted to give you an update about my 2 true clowns. I wrote to you about a week ago asking for advice about my clowns fighting their reflection in the glass. I am happy to say that they have given up this behavior and have adopted my Green Frogspawn. :) <Ah, good> I have a question if you have the time to look over the attachment I've sent. I have a Del-Ray sump that came with an over flow. It is the box kind that is attached with suction cups and uses a J tube to go down to the sump. I am having problems with it staying attached (the box inside of the tank that is.) <Yes... a poor design> My LFS does not sell these sumps anymore and does not know where I could find out the information about the suction cups used. On a totally different subject I want to purchase another overflow (so I can have one for each corner) and now I cannot find the manufacture (looked on the net and could not find it. I am not a surfer.) Could you please take a look at the picture I have attached and tell me if you know this sort of overflow. and where I might be able to find on like it? <See it... and not made by any extant company as far as I'm aware. Do look at the CPR units... Link on WetWebMedia.com> Also I thought that since I am moving and I will have to take my tank apart, could I use aquarium sealant and glue the box to the wall of the aquarium? <Absolutely... this is what I would do if satisfied with the unit... if not cut, drill the tank otherwise...> I don't ever intend to have them removed, so this seemed like a good idea. What do you think? I haven't found anyone who has done it so I am weary. Have a great afternoon and thank you for your time. ((sorry for the first picture being so blurry)) <No worries... have many more that are much blurrier. Bob Fenner>

Re: My crazy clowns (and overflow boxes) Hello again Mr. Fenner, Sorry to give you two emails in one day but I did want to thank you (yet again) for you help. About the overflows, I would like to ask another question. I have heard very bad experiences with the CPR overflows, losing there siphon and other scary things. <Mmm, actually, these makes/models are about as trouble-free as available, and reliable IMO> I have not had a problem with the one I am using now. I would keep using it because I thought drilling a glass aquarium when it has already been assembled is a disaster waiting to happen. <Can be... I wouldn't do it yourself... check around with the glass shops in your area for their opinion) I have heard it has a greater chance of cracking while being drilled and that it could loose structural integrity. <Crack, yes... a possibility. Loss of structural integrity? No, not if done correctly.> The tank I have now is 1 year old and does have a center brace at it's top. Do you think it is possible to drill for overflows and not have problems?. <Yes... this is a "stock procedure" in aquarium manufacture...> I will read over your web site and see if I can find anyone who has done this. I am just very weary at the idea of drilling glass. Best wishes <And leery. Bob Fenner>

Overflow Question Greetings, I have been experimenting with different ways of quieting my overflow before I complete the setup of my pre-drilled, 72 gallon, bow-front All-glass fish & live rock aquarium. I purchased a magnum 950 pump (following your advice -Steve) as my return pump. I tested the flow rate and this pump is pushing 540 gal/hr in my aquarium which I am very happy about (I collected the return water in a bucket and measured it out). After reading many posts regarding insufficient drain rates, I modified the All-Glass overflow kit to allow a 1.25" ID tube to drain into my sump. Needless to say my tank sounded like a flushing toilet and washing machine all in one. I was experiencing a huge siphon noise, a noisy waterfall effect in my overflow, and a very noise sump with lots of air bubbles. I also cannot increase the diameter of the drain hole or add another one because the bottom of the tank is tempered glass. After reading through hundreds of posts I came across someone who put a gate valve in the drain line and closed it just enough to exactly match the return pump's flow rate. I decided to duplicate this today (but with a ball valve for now) and the results have been terrific. The siphon noise is gone because the water level is far above the PVC drain pipe (I stopped using the all-glass float), the waterfall noise is gone because the overflow water level is only a few inches below the overflow lip, and the sump is very quiet because very little air is siphoned into the sump (also few air bubbles). I have read numerous times that you guys don't recommend any type of valve controlling the gravity overflow. <Yes> I don't understand this reasoning though, besides it being very difficult to exactly match the drain rate to the pump rate. Are there any other drawbacks by restricting the drain rate to match the pump rate that I can't think of? <There is a possibility of clogging the valve and causing the water level in the tank to rise to the point that you have a flood.> This seems to good to be true. I have been agonizing over my setup for 2 months now and desperately want to get the tank running. Your advice in the past and this website as a whole has been indispensable. <I think you would be safer with a Durso-style overflow modification. See his webpage here http://www.rl180reef.com/> Thanks, Jeff <You are welcome. -Steven Pro>

Overflows & FYI I have a 100 gallon acrylic tank with two overflows; opposite each other, on the right and left side of the tank. Since I bought the tank, one of the overflows has never really worked. I've had the tank for a year but recently I've been redoing a few things and the "dead" overflow is bugging me. I've tried all of the usual things. . .bled the return lines checking for clogs, etc. No success. As a side note, I'll also mention that the return line is not equal distance from the overflows. Picture this: the tank and stand are 60" long. The sump stretches across half of the sixty inches. The pump plus the exit line from the sump covers most of the remaining thirty inches. Naturally, the overflow on the right side of the tank is closer to the pump than the left side.  <should be of little matter on a level tank> However, oddly enough, it is obvious to me there is more water coming out of the left return line than the right. But it's the right overflow that works the best! Are you confused yet?  <yep> It appears to me that the left hand return is shooting water through the right overflow. This is not happening in the reverse. <er...OK> I though that overflows worked on the principle that the water level of the tank was supposed increase thereby gently spilling water into the overflow.  <again... on a level tank... the drop should be relatively even if the run is also similar enough (which it is likely to be from the bottom of each overflow. You don't have either (especially the slow one) releasing into the sump below the sump water level? Impedance> The tank has way too much surface agitation for the water to gently overflow. Any suggestions (short of draining the tank, etc.) to solve this problem? Oh, the system pump is rated at 1500 gph but it's going through a 3/4'' line and changes to 1/2'' line as the water enters the tank.  <restricted indeed! Do you need to? why not more flow (larger supply line)?> This tank was a Clear View aquarium design. I would never have had lines that small. <perhaps re-route the return with a simply flexible line off the pump and a u-tube over the top of the tank... even if only as an experiment> On another note. . . In the past, I have read many questions from people that own the Turboflotor 1000 skimmer. I have always been unhappy with mine (almost a year) until this week.  <if you aren't feeding this skimmer from a skimmer box in the sump with a static water level, then that has been most of the problem> Let me give a little advice: 1) Use a skimmer box to keep the water level around the skimmer between 10 and 15 centimeters, no more no less;  <ah-ha!> 2) if you've been using the skimmer, check for a clogged venturi, clogged feeder pump, or problem with the Rio 2600. <good advice.... thank you> I assure you, those two items alone will make a world of difference in the skimmer's performance, especially the skimmer box. <agreed... critical for all skimmers. A skimmer getting water from a pump/sump with a fluctuating water level is a great impediment!> Keep up the good work and thanks for your help! David D. <thanks kindly, Anthony>

Re: Overflows & FYI <<You don't have the drains releasing into the sump below the sump water level do you? Impedance>> ++++I'm not sure I follow. The sump is a homemade Rubbermaid. The overflow lines empty into the skimmer box about a 1/2'' below the water level. The lines simply rest slightly below the surface of the water.  <exactly as stated/feared above... in doing so air gets trapped and backed up. Overflow drains should never be even slightly under water. Release a whisker just above the water if you must be close but let the air escape... else it backs up flow> Are you suggesting an improvement? I'm game if it might help the problem. <as per above> <<perhaps re-route the return with a simply flexible line off the pump and a u-tube over the top of the tank... even if only as an experiment>> ++++Might be worth a try. But if the u-tube were to get loose. . . <sheesh... a hard U-tube bud clipped or clamped to the top... its just an experiment :) Be resourceful, my friend> I might also mention that I get a suction noise from the left return from inside the tank. This is not the flushing toilet sound that one gets from the overflow. I built a Durso style silencer when I first got the tank and it's been wonderful. The sound only happens maybe every twenty or thirty minutes. It looks like a little cyclone is forming right where the water leaves the flared nozzle and enters the tank. I have helped the problem immensely by turning the return nozzle clockwise. I just thought this might help give you another clue as to what the problem is. Maybe I should just leave well enough alone and continue using those powerheads. I appreciate your thoughts and efforts. Thanks again. <the flushing toilet noise is often trapped air... the cyclone is usually an undersized overflow drain or and oversized pump. Undersized commercial overflows are a dreadfully common problem. Few can ever handle reef sized pumps. Best regards, Anthony>

Sand Box - Overflow... Sand Box over-no 2/9/05 Hello again. <"...hello... just called, to saaaaay, hello."> I have a question that is specific to my setup. I've read through as much as I could find on your site about the topic, but have not been able to reach a conclusion and would like some input concerning a minor tank modification. My tank has overflow boxes in the corners. Each box stands the full height of the tank. Inside each box is the drain that sends water to the sump...The drains have PVC pipe inserted in them, that stand about 18 inches inside the boxes, topped by a strainer covered with a sponge pre-filter... <The norm... yes> This creates a bunch of open space under my prefilter that is inside my overflow box, always full of fast moving water, and unused space.  <Yikes! pull the prefilter completely. Unless you rinse this almost daily, it is severely handicapping your skimmate (total) potential and degrading water quality over time> The space also collects debris, shrimp, snails, etc.. <The weir edge of the overflow needs modified with a barrier like simple plastic gutter-guard (for rain gutters)> I think the boxes have about 5 gallons of water in them at all times. The boxes are about 8"x6"...My question is this: I was thinking of filling the boxes up to the prefilters with aragonite sand.  <yikes!> This would prevent stuff from collecting under my prefilter, inside the box, which is my primary goal.  <Best not to> But, I am also hoping as the water from the tank "waterfalls" into the overflow boxes, the turbulence will help dissolve the sand, adding calcium and minerals to the water. Do you think I will see that benefit?  <I don't think you'll see anything my friend... your tank will be as cloudy as milk from this turbulence> Would an 18" deep sandbed inside of an 8"x6" space be detrimental to the tank? Could it create problems? Would I enjoy any of the filtration benefits of a DSB?  <Yes, yes, and no> Thanks for your thoughts, and the great website. Scott <Thanks kindly, Scott :) Sorry for the quickie :p Anthony> 

Re: Overflow prefilters 2/10/05 Geez...I'm glad I asked first, I was way off base. Thanks. I am wondering about the prefilter comment though. If I remove the prefilter, where will my mechanical filtration occur?  <Hmmm... not really needed if the skimmer is aggressive enough, but if not... then in the final stage before the return pump (presuming there's no pod refugium inline)> Do I even need the mechanical aspect of the filtration?  <Not really. Do you at least get several cups of skimmate daily from your unit? If not, see the archives here as well as the sticky post on "skimmer production" at the top of my forum at reefcentral.com> Will not having the prefilter send my skimmer into overdrive? <I hope so :)> I'll do some searches for info about pre-filters on your site too.  Thanks again, Scott  <Best regards, Anthony>

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