Sand questions 11/11/08
Greetings from Singapore!
<Hello! Jessy here. Greetings from southern California!>
Got a quick question for u. I have a 11 month old 3ft, 60gal, FOWLR tank with some grade '0' sand(around 1" deep). Since my wavemaker pump keep pushing my sand away to the side(leaving a huge gap in the middle of my tank), I decided to add more grade '0' sand to make it deeper(around 4" deep). Will it be causing any problem to my Livestock/Tank?
<Adding new sand shouldn't cause any issues to your livestock, if it was new sand. You could possibly have a small ammonia spike if there was anything in the sand that would die off, but generally speaking you should be safe. As a precaution I'd keep an eye on your levels and water changes are always a great way to prevent any unforeseen disaster.>
Thanks,
Andrew Munday
<Regards, Jessy>

DSB question and more 6/16/08 Hi.. <Hello Mohamed!> Better to give you details on my reef aquarium.. I have a 90 gallon aquarium with a 25 gallon sump, OR1200 return pump, AquaC EV180 skimmer, 1 Tunze stream 6060, 2x 150w 14k Metal halides, 4x54w Aquamedic actinic T5 lamps and 2x54w T5 white 10k lamps. <Sounds like a great setup.> I have a 4.5inch DSB with no plenum. Is this okay??? <Yes, definitely.> Secondly, my sand bed is very dirty most of the time... what should I do to remedy this? Will more flow help?? <More flow is one of the primary tools to keep the sand from accumulating detritus. Small sand stirrers such as Nassarius snails can be helpful too. If your sand is dirty with algae or BGA, that is another issue.> How’s the algae free sure flow mod for the Maxijet 1200?? <It is great, I love them. I was part of the pack the last few years fabricating my own, the new drop in kits are lifesavers. Low power draw, quiet and tons of flow.> Furthermore, the sand I use is very fine... about 0.5mm or less. It is about 2 years old. Due to this, a lot of sand keeps blowing in my tank and it always goes on top of rocks and stuff no matter where I point the Tunze. I’m going insane trying to control it even without the Tunze. <It will take a bit of trial and error to get it right, but it can be done. You will likely find it easier to keep your sandbed in place throughout most of the tank with the addition of another powerhead (such as the MJ mod). Colliding the flow from the two can provide a greater, but more dissipated flow. With one the directional flow can be tough, digging troughs that other sand then falls into, continuing the cycle.> Note: Tunze is on the back top right corner of my 48"x24"x18" tank and is pointing straight to the other end (length wise). Should I use a coarser grain of sand to avoid this problem?(2-3mm).. If so, how do I do it in an established aquarium? <You can if you wish. I personally like the sugar fine sand. If you do want to switch you can siphon out the sand with your water changes over a period of a few weeks, then replace with the new. One word of warning: if your rocks are supported by the sand you will end up with a rockslide. If this is the case you may have to teardown the system to switch. Again, the fine stuff can work with some experimentation with flow.> Also, I got Caribsea Aragamilk and have been using it for 3 weeks and my calcium is still 300-320ppm.. I stopped using Kalk due to pH fluctuations. Also on your recommendation, I have purchased a Milwaukee ph controller and GEO 618 calcium reactor to remedy this but the shipment has not yet arrived (will do so in a week). Will the reactor be able to pull the calcium up to the 400s? <It can, but with an increase in alkalinity too. You will want your Ca and Alk in balance, then use the reactor to keep it that way.> Is there anything DIY I can do in the meantime? <For the amount of time you are looking at you will want to simply buy a small quantity of another Ca supplement or increase your water changes to get things in balance, assuming your salt has a higher level of Ca (it should). > Thanks a bunch and I hope you guys can help me make my tank look good... PS: how’s the blue background at the back of the tank? Should I change it? <Looks good if you like blue backgrounds ? A personal choice that will be covered in coralline with time!> Mohamed. <Welcome, thank you for writing, Scott V.>

RDSB Water Flow Questions 12/21/2007
WWM Crew,
I just finally finished reading the many pages of information on deep sand beds and nitrate reducing methods. I found it to be an excellent discussion and a wealth of information. However, I have a question that remains unanswered...
For background, I have a new 210G BB SPS dominated tank with a 60G sump, and I'm using a 75G AGA (48" x 18") for a RDSB with 6" of sugar size sand. The RDSB is not lighted. I have 150# of Tonga LR in the main display. I'm using a Reeflo 250 Orca as my skimmer and I typically run carbon passively in my sump. Flow through the entire system is high with detritus staying in suspension and being removed via a filter sock in the sump. My main focus/desire for the RDSB is for nitrate reduction followed by an increase in bio-diversity of the overall system.
I'm interested in opinions on both (1) overall flow through my RDSB as plumbed into my total system (currently I'm moving less than 200G/hour through the RDSB tank with the returns directed at the top of the tank)
<This sounds good to me. I'm sure opinions vary on this, but I think as long as your moving about as much water in an hour as you have in the main tank, you're probably good. Of course, to a point, more is probably better.>
and (2) flow within the RDSB, not only in volume, but with respect to how, where, and by what means (currently I have no additional flow other than the main returns).
<Water flow actually THROUGH the DSB is largely dependent on the benthic life of the sandbed. You want to have a lot of worms, micro-crustaceans, etc. living in the sand to turn the sand grains around. This is what moves water down and through the sand.>
Specifically, I'm interested in opinions on flow techniques at the sand/ water interface level.
<If you want to add more water flow above the sand bed, you can just add a powerhead. If you don't think you can do this without creating a sand storm, you could try piling some rocks in one corner and pointing the powerhead at the rocks from the other side of the tank.>
Thanks in advance and thanks for maintaining this excellent resource.
Tony
<De nada,
Sara M.>

Exciting new question... same old DSB questions – 09/13/07
Hello.. (sorry for subject line, just trying to inject some excitement as i know you must get flooded with the same questions)
Compliments on a great site, so much information, and it seems, a complete information overload for my brain.
My husband and I have been in this hobby for 9 months and have fallen in love with it to such a degree that we have just upgraded from a 42 gallon (UK) to a 130 gallon. (30 gallon sump) inhabitants will be fish (yep!) LR, inverts. The old tank had 1/2 inch crushed coral sand this has now gone.
We fully intended to go with a DSB for this new tank as we were under the impression this is the best way to go, our LFS (bless them) said not to, as it can release sulphur back into the system which will kill all livestock?
<Ugh... this is just not true.>
Obviously we want to set this tank up right, from the start.
In your humble opinion, should we go for a DSB in the main tank (4 + inches of aragonite, live sand or normal?)
<Sand beds are great for keeping nitrates low and adding biodiversity to the tank. Fine aragonite is preferred, but pure silicate sand-box or masonry sand will do just fine. But whatever type of sand you end up getting, you'll need to "seed" it with live sand and live rock. Please start here: http://www.wetwebmedia.com/deepsandbeds.htm
and try here: http://www.reefkeeping.com/issues/2003-06/rs/feature/index.php
and do a search on WWM and/or Google for deep sand beds. There's a whole lot out there written on this topic.>
should we also have a DSB in the sump?
<If you have one in the display, you don't need one in the sump. But it's up to you.>
or shall we go with Miracle mud?
<Miracle mud is not necessarily any better than any other type of fine, live sand.>
I assume we would need sand sifters of some description as well.
<You need worms and other critters, but not sand sifter stars (or other such echinoderms which can actually destroy sand beds). Again... do some research. There's a lot out there to read.>
As there is so much information, pro's and con's, it can be confusing and I guess it's personal taste but any advice would be greatly received.
<Do a lot of reading. This is the only real advice I can give you here. Don't just go by what the LFS tells you (and that applies to just about everything).>
Thank you in advance,
Nicola
<De nada,
Sara M.>

New Tank Question: DSB and Water Movement    7/30/07
Hi James,
How is everything? Hope everything is well.
<Hi Jon, everything fine here.>
Before anything else, I am happy to tell you about the Fromia millepora (red sea star) that I have inquired about. I was so happy when I finally moved him from my quarantine tank to the display tank. He immediately went around and took some algae I left for him in the front of the glass. He's been all over the tank already and for two days now seems doing just fine. I love him and did add diversity in the tank.
<Good to hear.>
James, you have seen pictures of my tank and it is indeed very healthy as you have mentioned. I probably have over 50 baby snails by now crawling about the tank thanks the initial 10 Cerith snails that kept laying eggs. Moreover, just tonight, I believe I saw the eggs of my 2 clown fish. I feel it is their egg as they were protecting it unlike the eggs laid by my Cerith snails that they very much like to nip. Oh boy, it’s been truly a wonderful experience for me. Love every minute of it.
<Can be a rewarding hobby.>
The sponge that has grown at the back of my LR is now protruding upwards and has covered the top of this rock and is exposed to total light. It is quite interesting to note that the color on this one however is orange yellow. At its current growth rate, I may not have room for new corals at all.
As you know James, this is my 1st venture in having an aquarium and a SW tank at that. I really could have not done it with your help.
<Glad to be of assistance.>
Old tank questions (60 gal):
1st. I have been setting my eye on some Holothuria cucumbers (particularly the tiger tail). I prefer them over the sand sifting star (which I read devours everything in the sand).
<Anything dead, yes.>
The thing is for weeks now, since I last wrote you, I have wanted to add more diversity for my current tank. I am not satisfied yet with the research I have done on it so far. There is simply too much variability for me to make any realistic generalizations about the risk of this specific sea cucumber. The best generalization that I can make is that for most deposit-feeding sand cucumbers the risk of a tank wipe-out is quite low and considering the added benefit plus bio-diversity in my tank, I am beginning to feel it is worth a try. Am I right in thinking this? (My first question). Secondly, if I am to put it 1st in my quarantine tank for 1 month, how am I to feed it? Lastly, how do one properly acclimate this? Is it the same as your advice to me as the red sea star?
<Jon, I'd stay away from cukes, they can be more trouble than they are worth. Read here if you haven't already.
http://www.wetwebmedia.com/seacukes.htm The sand sifting starfish would be a much better choice. Keep in mind, these guys
should be fed unless you have a well established sand bed. I feed mine with a syringe (no needle attached). I take the syringe and
draw up a few bloodworms and inject them under the starfish. Has been working well so far. They will also eat dried Nori.>
2nd. I know Phosphate less 0.03 concentrations is a good value for reef aquaria. Last week, I purchased a Red Sea P04 test kit and for the 1st time have tested P04 concentration in my tank and found out that I have about 0.1 ppm PO4 level.
<More than likely you are just reading the low end of the scale and is not indicative of the actual level. Phosphates are generally
absorbed in the system very quickly.>
I am not having hair algae nor some red slime outbreak or anything but want to make sure I won’t have them at all (I do have some hair algae but is controlled in just one spot and comes and goes). I have a refugium with lots of Chaetomorpha algae that I trim from time to time which I believe helps (thanks to your advice early on). Does putting some ROWAphos or PhosBan in a poly filter bag and hang this by the sump do the trick? Or is it really necessary to get a Phosphate reactor as some other guys in other websites seems to strongly suggest for some fluidize action. I ask because everything seems fine…”Now” but I don’t know why I keep worrying about something that has not happened yet. Also I feel I don’t really want an absolute zero PO4
at all because my current tank seems to be thriving (I have maiden’s hair and shaving bush plants in the main display tank and some spaghetti algae in the refugium).
<I'd leave well enough alone, but if I decided to use a product, it would be Rowaphos.>
New Tank (2009 7’x3.5x2’ Upgrade tank)
1st question. Given the size of the tank, if you were me, how big/ proper ratio should the refugium be if I were to use DSB on it? How deep of a DSB would you go? Will you employ the use of a plenum (mix opinion on its usage - quite confusing)? Main tank will have at most 2 inch of live sand. I ask this because I read somewhere here or maybe Mr. Anthony Calfo's book (I can't remember) that a refugium size 20% of the display size is recommended for effective NNR. I also remember reading here a long time ago that a small amount of nitrates is beneficial or even necessary for keeping corals and to target 1-5ppm.
<Jon, do search/read on our site on DSB's and refugiums. There is too much info available for me to write here. Yes, small amounts of
nitrates are beneficial for plant/algae growth, and clams will also absorb it.>
2nd question. Again if you were me, what system would you use with regards to water circulation and proper water flow if you want to keep mostly SPS with a few LPS and soft corals? This tank is going to be in the center of the room viewable on all sides with pipes running to a room (about 15 feet away, piping under the floor boards) for the stuffs needed to keep the tank thriving. Obviously, the overflow is going to be in the center of the tank which is why I am having quite a fascinating imagination of how I am going to properly move the water. I want to eliminate as much as possible using powerheads attached to the glass.
<I'd bulkhead the water coming into the tank and use a couple of the SCWD' (Switching Current Water Director) in the system. Again,
this subject should be searched on our web site, too much info requiring too much time to do here. Go here. http://www.wetwebmedia.com/plumbingmarart.htm One thing to consider in planning is
the distance from tank to pump. Every foot of pipe used will lower the pressure/flow rate of the pump and the amount of water that
can be returned to the sump. Here is a link to some
useful information regarding this. http://www.reefcentral.com/calc/hlc2.php>
Lastly your thoughts on the best skimmer out there to blow waste off this upgrade tank. I was thinking of Precision Marine Bullet XL Model 2 protein skimmer. My second choice is a Deltec Protein skimmer but they are just way too expensive for me.
<Personally, I like the AquaC's. Virtually hassle free and very efficient.>
Thank you so much again James. It has been truly a joy writing you.
<Why thank you, Jon, and good luck in your new venture.>
Sincerely,
Jon G.

DSB, gen.   – 07/03/07
Morning crew! I've come to bother you for some more advice...
At current I have a 55g tank with roughly 45-50lbs of live rock and nothing filtration wise but a prefilter and a recirc skimmer in my sump. Being as I've had my old 30 gallon tank glaring at me for some time now, I though about adding in a refugium with a DSB for added filtration/denitrification and fauna production for my dragonet. Is it reasonable to try and add this after my tank has been setup?
<Sure>
My plan was adding about 6" of fine to medium grade sand and a few pieces of (cured from my show tank) live rock to get things started.
<And/or you should add about a measuring cup or two of your live sand from your established tank.>
Does a DSB have to be cycled and functioning before I plumb it into my system?
<That depends a bit on what type of sand you'll be using. Aragonite sand can leach stuff (like phosphates) when it's "new." So if you use aragonite sand, you might want to "cycle" it for a little bit before attaching it to the main tank. On the other hand, silica sand (masonry or classic sand box sand -- i.e. the kind that makes glass) should be good to go after a good rinsing with RO/DI water.>
Or would I be fine to set it up and turn it on with no ill effects?
<See above. :-)>
My second question is on what inverts I should populate my refugium with for adequate sand stirring? Unfortunately to date I've not found any information on the subject that actually recommends anything specifically, simply "add sand stirring inverts" but perhaps I've not looked hard enough?
<Well, if your current sand bed is well populated, then the answer is simple... just use your old sand to "seed" your new sand. If not, try looking for starter (or "seeder") live sand sold at a variety of places online (not the stuff sold in bags, the stuff kept and cultured in tanks). The "live sand" sold in bags is good stuff, but it's not likely to have much in the way of critters (probably mostly just bacteria and some other microbes). To get the good worms and everything, you'll need live sand that's been cultured in a tank. Or, you could just bum some off a fellow reefer with a well populated sand bed.>
Thanks for the help,
Mike
<De nada,
Sara M.>

Another DSB/Nitrate Reduction Question – 06/23/07
I have a 58gal tank + sump with approx 45lbs live rock, crushed coral substrate.
<<This last is likely a large contributor to your Nitrate issue>>
A Finger Leather, a few Mushrooms, Xenia, Zoanthids and some Yellow Polyps.
<<But for the Xenia, quite a noxious combination>>
All are small and well spread out.
<<But in a relatively “small” volume of water…do employ some purposeful chemical filtration (Poly-Filter/Carbon)>>
Livestock = Yellow Tang,
<<Tank is not big enough for this fish, mate>>
Maroon Clown, Royal Gramma and a Sixline Wrasse + Snails and Hermits.
<<Not that you should consider it now, but if things change, that Pseudocheilinus will make future fish additions problematic>>
Protein skimmer that makes about an 8-12oz of dark skimmate a week. My nitrates are consistently in the 20s.
<<Ah yes, this needs to come down. It’s hard to say for sure but, perhaps you need a better/more efficient skimmer>>
5-gal water change every 2 weeks with aged RO water.
<<Allowing the salt mix to “blend” for several days I hope>>
It’s understood that by increasing water changes, I will dilute the Nitrates, but I do not want to have to do this on a permanent basis.
<<Mmm, understand the mindset…but on this small volume this is an inexpensive and most healthful process. And doubling the volume to 10-gallons could make a very big difference here>>
Reduced feeding does not seem to help reduce the Nitrates.
<<Coming from somewhere else>>
It seems that I have a lot of debris in the crushed coral even after using a gravel vac.
<<Course substrates can be very problematic>>
I have taken some crushed coral out and cleaned it but I am afraid to do a lot at once for fear of shocking the tank.
<<Mmm…may not be much of an issue if the existing depth/volume is small>>
I think that a DSB is the way to go.
<<I am a strong proponent of this methodology>>
After the DSB is up to par I would add more live rock.
<<Don’t act too quickly re the rock…fishes need room to roam>>
At the present, 100lbs of pet store aragonite is not in my budget.
<<The retail side of the hobby IS proud of this stuff>>
I see 4 ways to get to my goal of having a DSB. 1) Remove all of the crushed coral at once and add a bag at a time of aragonite over several months until it reaches the 4-6 in. depth. 2) Add a 12x16x4 DSB in the sump inside a plastic container and then do the above. 3) Wait until I can get enough sand to do the change at one time. 4) Wildcard option, to use limestone play sand that I found in a local Home Depot (Chicago region).
It did pass the vinegar test, but it does not say where it is from. The pallet is in a slot marked Old Castle but I did not see Old Castle on the label, I can/will check again.
<<This is probably not Limestone but rather Aragonite sand…and most desirable/useful as such re our hobby>>
If these were your choices, what you would do?
<<Hmm, a combination of all these choices! I would purchase sand from Home Depot…add the DSB to the sump and wait a week…remove the crushed coral from the display and add the full depth of sugar-fine Aragonite to create the DSB… And do consider rinsing this sand before adding to the display. Some authors say this isn’t necessary…and on new systems it is less of an issue…but I speak from experience when I say you will not like the result if you merely dump this sand in to your existing display without rinsing away at least “some” of the “fines”>>
Until the nitrates are lower, I will not add anything and will have to increase the water changes.
<<Good>>
I consult the WWM regularly and am thankful to all of the crew for the comprehensive site.
<<The “Crew” is happy you find the site useful>>
I do not understand how you all have the time and patience to answer our repetitive questions.
<<Hee-hee! Can be trying at times for sure…but the greater good we “know” we are doing far outweighs the occasional inconvenience or thoughtless/selfish querier. And to be fair, the “Crew” has it easy compared to Bob who must “handle” all the queries we leave, as well as maintain the site/post all for the public’s edification>>
After reading your daily questions for a while, I have come to the conclusion that many of us who ask questions (myself included) are not ready to accept the hard truth; we want a magical cure to Ich and other problems, as in my case Nitrate reduction.
<<Ah yes! Tis true many write in looking for validation for something they know is wrong, and subsequently refuse to accept the “hard truth” as you say…but by far the majority of folks are just looking for some “personal” attention/guidance to their dilemmas. And as we often tout here…nobody should rely on a “single” source for their information anyway. Hobbyists should research/attempt to gain information from a variety of sources (books, NET chat forums, WWM, hobby clubs, etc.) and use their own good judgment to choose a course of action…WWM is just one cog on the wheel>>
Thank you!
<<Quite welcome…and “thank you” for this opportunity to rant [grin]. Eric Russell>>

DSB Size/Depth - 08/29/06
Hi again,
<<Hello>>
I am trying to add a DSB for my 125 FOWLR due to a persistent nitrate problem.
<<Ok>>
I do have sand in the main display at present but due to the home improvements done by my fish on a regular basis the SB is 2-3" in some spots and much less in most others. (Apparently they don't understand the benefits and keep moving it around when I try to fix it.)
<<Ha!...indeed>>
Be that as it may, how big of a sump/refugium and how deep of a SB would be an appropriate remote DSB?
<<In my opinion...As large a vessel as you can practically employ, with a "minimum" 6-inches of sugar-fine aragonite>>
I also have close to 200lbs of LR in the system.  Thanks again for all your help.
Mordy
<<Regards, EricR>>

DSB/Wet-Dry/Nitrates - 08/28/06
Hi there!
<<Hello!>>
How are you all today!
<<Don't know about the rest, but I'm doing fine, thank you>>
I hope I am not bugging you with a repeat question.
<<No worries my friend>>
I have read thru all your FAQs on sand beds and am getting confused.
<<Oh?>>
There seems to be many contradictions and I really want to get it right.
<<Indeed...differing methodologies/opinions...>>
I have a 220 gallon setup that is about 8 months old.  I used 220 lbs of live rock to set it up as well as about 120 pounds of CaribSea live sand.  That gave about an inch of sand on the bottom.
<<Ok>>
I also have a wet-dry running and am not sure if this is necessary and will contribute to higher nitrates.
<<The wet-dry filter is not necessary, or even desirous, if this is a reef system...but can be beneficial to a FOWLR, though these days my preference when additional bio-filtration is needed is to turn to a fluidized-bed filter>>
My nitrates are around 50.
<<Mmm, you have a problem then, in my opinion.  Nitrates should be <5ppm for a reef and <20ppm for a FOWLR>>
I have an ASM G3 protein skimmer and a Blueline 40HDX pump.  After the first few months of losing several fish, my tank seems to be settled and I have had luck with my fish for the last 4 months without any casualties.
<<Won't last with nitrate readings this high.  Though maybe not immediately evident, the high nitrate level will have/is having an effect on the fish and will cause problems/deaths in the long-term>>
I'd like to get my nitrates to 0 and am wondering if I should increase the sand bed to at least 4 inches and get rid of the bio-balls.
<<One approach>>
I could also add some more live rock.
<<Sounds like you have a lot of rock in there already>>
Would you advise this or should I stick with my 1/2-1 inch sand bed (I lose some sand every week when I vacuum as it's fine sand)?
<<I'm a fan of DSBs...I would try increasing the depth of the sand bed...and stop the weekly vacuuming as this will be counterproductive to the DSB.  If detritus accumulation is a concern, then increase water flow in the tank>>
If I made it a DSB, how would I go about it with all the fish and live rock in there?
<<Considering the current depth/weekly vacuuming, simply add the sand until you reach the new desired depth.  Pre-rinsing will help to reduce the associated cloudiness>>
Can I purchase a different kind and put it on top?
<<You can>>
I would like to add some pink.
<<Won't stay "pink"...I recommend a sugar-fine substrate, though you can go a bit larger if you wish (1mm-2mm)...or even go with a mix of these>>
Also, would the LR need to be removed if I was adding 3 or 4 more inches?
<<Nope...in fact, I prefer to place my live rock on the tank bottom and fill around it with the sand for better stability>>
What about the fish?
<<If you go to the trouble to pre-rinse the sand to reduce the "fines" suspended in the water column they should be fine.  If you wish, you could even add the sand in stages (a day or two apart)>>
I really have no where else for them to go as it's a 220.  Maybe knowing my fish would help determine what sand bed is best for my tank.  I have a Bluefaced angel, a maroon clown, a purple and sailfin tang, a fairy wrasse, a Twinspot wrasse, a zebra moray and a few gobies.  Also 2 anemones and a couple starfish and hermit crabs.
<<Yikes!  Anemones and 50ppm nitrates?  Maybe you should try testing with another brand of test kit (Salifert, Seachem) to validate this reading>>
I have had a little trouble with red Cyanobacteria and have been physically suctioning it out every week as well as weekly water changes.  I can't get it all off the rock but do blow some of it off with a bulb syringe.  I was wondering if increasing the sand bed would help get rid of that as well as hair algae which I have a little of?
<<The DSB will provide numerous benefits, one of which will be the reduction of nitrogenous compounds (algae fuels), but an increase in water circulation will also help with the Cyano>>
Any help in resolving the sand bed issue once and for all for my setup would be greatly appreciated.
<<I think a 4"-6" sugar-fine DSB to be a worthwhile addition.  As for the wet-dry, you might try replacing the bio-balls with fist-sized pieces of live rock and see if that helps with your nitrate.  Adding some carbon/Poly-Filter somewhere in the filter path will also prove beneficial>>
I want to do the best I can for my fish and make it as healthy in there as I can for them.
<<Then address/determine the source of nitrate and bring that reading down.  Do have a look here and among the links in blue at the top of the page:  http://www.wetwebmedia.com/nitratesmar.htm >>
You have such an awesome website and I read it often.
<<Were pleased you find it of use>>
Thanks so much for all your help.
Heather
<<Happy to assist.  Regards, EricR>>

Re: DSB/Wet-Dry/Nitrates - 09/01/06
Hi Eric!
<<Hello Heather!>>
I think I'm becoming your groupie.
<<Hee-hee!  Cool, I think you're my first!>>
Thanks so much for your speedy reply. I was shocked how fast you wrote back.
<<A matter of timing/luck for the most part>>
And it's nice to converse with someone who cares about this hobby and doesn't roll their eyes at me when I ask too many questions.
<<Mmm, indeed...too bad your LFS doesn't see the value in education/keeping their customers in the hobby...or maybe they just don't have the capacity re>>
(Well maybe you are but I can't see it at least like at my LFS)
<<Ha!  I'll never tell! (and spoil my image <grin>)>>
I've been reading and am considering the Tunze Turbelle Stream pump.
<<An excellent choice...I use these for water movement in my own system>>
It's around $190.
<<Not cheap, but excellent quality/engineering/performance>>
Is it all inclusive or do I need to buy anything else with it?
<<Based on the price I'm guessing you're looking at the model 6080?  This is a synchronous-motor pump (does not run on a controller/wavemaker) and is ready to go out of the box.  But, depending on your tank design/bracing, you may need one of the holding device extensions (3000.244 or 3000.260).  These should be available on the site where you purchase the pump (if not, they can be found at MarineDepot.com), just review the information on each and determine which is needed (if any) for your tank>>
The internet stores don't really say much but they talked about timers and wave controllers.  Is any of that necessary?
<<No...and not possible with some pumps/powerheads>>
Where is the best place to put it in the aquarium?
<<Hmm...distal from the sump return line...and positioned toward same for creation of a random turbulent flow pattern>>
Would one be good since it says it pumps about 2250 gph on top of my 1200 gph I'm already getting?
<<If this creates enough water movement to keep detritus in suspension/eliminate dead spots, yes...will likely take a bit of experimentation to determine the optimum position (or number of powerheads required)>>
I have a feeling that more gph would definitely help with the Cyano.
<<Me too, though other factors to consider as well.  Have you read our articles/FAQs on blue-green alga?  Here's a good place to start: http://www.wetwebmedia.com/bluegralgae.htm>>
I always worried 5X wasn't enough flow but again my LFS disagreed with me.
<<You must evaluate the needs/requirements of the livestock, but it is likely an increase in flow will be appreciated...even "enjoyed">>
I'm trying to find another LFS but I live in Melbourne Beach Florida and unless I want to drive 90 minutes there are only 2 close by.  I'm not too happy with either.
<<I see...best to arm yourself with "your own" knowledge/research>>
You were right about the 300 ppm nitrates hurting fish.  When I sat down and worked out where all my fish losses were from, they were all from that store.
<<Indeed...as if the stresses of capture/transport weren't enough already...>>
I think I lost 8 out of 10 of the fish purchased there for a loss of about $500.
<<a pity>>
All my other fish purchased elsewhere have done fine.
<<Hardly a scientific analysis...but does seem rather telling>>
I guess they only care about the bottom line.
<<Unfortunately there are stores out there with kind of short-sightedness>>
Neither store carries live rock and the store that did and had a conscientious owner (shocking), went out of business.
<<...why does it always have to be the good one's...?>>
Do you recommend any internet sites for quality cured rock?
<<Some of the members of my local reef club have been raving lately about the rock offered at Reefermadness.us >>
I guess that is it for now.  I'd like to purchase a quality pump that gives good gph and add some more LR and see how that goes.
<<Sounds fine>>
I read the links you sent me as well as Anthony's report on pumps and like the Tunze like you suggested.
<<You won't be disappointed>>
Thanks so much! Heather
<<Cheers my friend, Eric Russell>>

DSBs...Bed Size/Sand Type/Depth   8/12/06
What's happening?
<<Good Morning!>>
I just got my brand new 135 gallon (72x18X25) glass aquarium the other day (got a good deal at Glasscages.com, in case some one
needs a recommendation on an inexpensive source) and am planning on setting up a new reef.
<<Cool!>>
I want to use my old 55 gallon that I have now for the refugium.
<<A great idea>>
I have been doing a bit of reading about the proper depth of the sand bed and came to the conclusion that is should be 1/2 inch and no more or 4-6 inches and no less.
<<Depending on what you want from it/what you want it to do, yes...a good "generalization">>
I wanted to run my plan by you guys (and ladies) and get an expert's opinion.
<<Have never considered myself an "expert", but I'll be glad to share my opinions/experiences>>
Because I don't care for the looks of 6-inches of substrate and aren't looking forward to spending hundreds on sand, I plan on only using 1/2 inch of sugar fine aragonite in the display and packing the 55 gallon refugium with 6+ -inches of slightly coarser aragonite to get the benefit of the DSB.  What do you think?
<<This sounds fine and is a quite acceptable alternative to placing the DSB in the display tank...though the total surface area will be quite less, as your are aware I'm sure>>
I'm assuming once I install the baffles I will have about 30" of the original 48" of space in the refugium to cover with the substrate.  Will this be substantially large enough to do the job, or is the 6-inches in the display needed as well?
<<All relative...the DSB in the refugium will be effective...just not as effective as a larger DSB in the display.  Whether or not it is effective enough will depend largely on the stocking density of the display and your aquarium maintenance habits/husbandry skills>>
Will adding more than 6-inches in the refugium be even more
beneficial or would it be overkill?
<<Depending on the coarseness of the substrate you use, a few additional inches could be beneficial>>
From what I read it sounds like DSBs need more flow to keep nutrients from building up.
<<A healthy flow rate does help, yes>>
Would you recommend an under gravel filter with some powerheads, or just a strong pump circulating the water from the refugium to the display?
<<Definitely the latter>>
I also wanted to ask what you thought about oolitic sand?
<<Is ideal for marine sand beds/DSBs>>
I saw an ad on EBay with decent prices.  All it says is that it is oolitic, .4mm-1.6mm, consists of aragonite, dolomite, calcite, crushed coral, and shells.  And it comes straight from the ocean
here in the US.  Doesn't really specify where and therefore I'm being a bit cautious.
<<Mmm, might be wise.  I believe there's only a few places where "aragonite" sand is collected...haven't ever heard any were off our own shores, but I'm not an authority re.  You might want to try/order a small amount and give it the old "vinegar test" to see how much of/whether it is truly aragonite>>
Thanks for all your help.
Jon
<<Happy to assist.  Regards, EricR>>

DSB..., Denitrator, Substrate Type/Adding Snails - 08/10/06
I have decided to install a DSB in a large bucket after trying for months to set up an AquaMedic NiTRATE reductor 400, without success.  It would either produce sulphur or nitrate because the turn flow valve was very difficult to adjust, making it difficult to get the correct flow rate, the drips were either too fast or too slow, it was a right pain.
<<Indeed...manufactured nitrate reduction equipment always seems too "fiddly" to me, no matter which design you choose.  I think you will have better luck with the DSB>>
During my visits to various aquatic shops in the area, I am getting many different reasons for and against the use of DSB's, also the use of various different types of media.
<<Not surprised...some folks love'em, some folks hate'em...and even among those who employ a DSB opinions will vary on application.  But the basics are the same...a deep enough bed for the size granulate chosen to permit adequate stratification of the different bacterial zones>>
One that has been proposed is the use of PLAY PIT SAND; have you any thoughts on this?
<<I do...the "play" sand is quite suitable for nitrification purposes and will perform this function as well as aragonite sand of the same grain size...but...the play sand will not provide any buffering capacity and it is decidedly "sharper" than aragonite which "might" be rough on some of the critters which will inhabit the sand bed.  The play sand will work fine, but my preference is sugar-fine aragonite sand...or even a "mixture" of the two if obtaining enough aragonite is an issue>>
I was also thinking of using sand snails to help with the movement of the upper layers of sand within the DSB.
<<You can do this (Nassarius and/or Cerith species), though it is not necessary.  Sand dwelling/stirring critters will find their way to the DSB in time>>
Will they require feeding or will they manage to survive on their own?
<<Possibly...best to let the DSB mature for several months before adding>>  
Any feed back on this would be gratefully appreciated.
<<You have mine>>
Phil Bowen
England
<<Regards, Eric Russell...South Carolina>>

Small Refugium DSB - 07/26/06
I made a 5 gallon refugium that sits behind my main tank, a ten gallon, with the goals of nutrient export, pod production, pH stability and increased water volume.
<<Excellent>>
I was planning on putting Chaetomorpha, live rock rubble, and some sand in this refugium and running it on a reverse photoperiod.
<<Okay>>
My question is would I see any benefits from a deep sand bed in this size refugium (the sand area's footprint would be 5"X15") or would I be better of with a shallow sand bed and more water volume?
<<Everything is relative my friend...considering the small size of the display, this particular DSB could indeed provide some benefit>>
Thanks a lot for any help you can give me.
Eli
<<Is my pleasure to assist.  Regards, EricR>>

DSB Canister Filter? - 07/24/06
Hello,
<<Howdy>>
I just started the fish keeping hobby and I established a 90 gallon reef tank in my living room.
<<neat!>>
While doing research I came across the process of denitrification.
<<Okay>>
I came to understand that Nitrate filters are not reliable.
<<Mmm, probably not so much "not reliable" as "fiddly"...requiring constant attention/adjustment to optimize their usage>>
Instead, I read that a DSB could be very effective at reducing Nitrates.
<<Indeed>>
Well the thing is, I don't want to add a deep layer of sand in my display tank, and since I can't get a sump (there's no space under the tank) I came up with an idea that might seem weird: Could I apply a thick layer of sand in an empty canister filter to act as a DSB filter?
<<Mmm, no...aside from not being a large enough volume to be of benefit, pressurizing/running the filter will cause the water to be "forced" through the entire volume of sand. This will defeat the denitrification process as there will be no "stratification" of the sand bed with the varying levels of oxygen allowing the different classes of bacteria to form/populate...all of which are part of/necessary to the process of denitrification>>
I imagine it will fulfill the role of a sump.
<<Not in my opinion>>
Please correct me if I'm wrong.
<<Since a sump is out of the question, you might wish to look in to the addition of a "hang-on" style refugium in which to place the sand bed.  Another option would be if you have room "over" the tank to place a large (salt) bucket half-full of sand with water pumped up to the bucket and allowed to gravity drain back to the tank from a bulkhead fitting placed just below the lip of the bucket>>
Also, I live next to the sea, where the sand in the coastal areas is extra-fine (which I read is preferable for DBS).  Could I use this sand? or is it a bad idea?
<<Best not to use it due to the possibility of introducing pollutants/pests>>
One last question.  Concerning macroalgae, how effective are they at denitrification?
<<Not so much "denitrification...is a different type of host/environment, performs a different function from the deep sand bed...yet still useful through regular harvesting for removal of organic compounds (including nitrate) as part of their nutrient uptake>>
Also is there a problem to add those in my display tank (I'm particularly interested in red macroalgae)?
<<Can be done, though some species can be very invasive (e.g. - Caulerpa sp.) while others might be quickly consumed (e.g. - Gracilaria) by some fish species (e.g. - Tangs/Rabbitfish)
Sorry for the long read.
<<No worries mate>>
Any help will be greatly appreciated.
<<I hope I have>>
Thank you.
Mohammad
<<Regards, EricR>>

Protein Skimming Power/Phosphate/DSB removal  7/15/06
Hello,
Thanks for running such a great site.  I've learned so much from reading your Q&A's.
< Bob and the others do a wonderful job! >
I have a 55g reef tank with about 50 lbs of live rock and a 4" deep sand bed.  It's about 15 months old and so far everything has been working very well, except for a recent, steep phosphate spike.  Is that typical for a DSB?
< No, that is not typical at all. >
  (I don't believe it is from overfeeding.)
< Are you feeding frozen foods? If you are not rinsing the foods well, the phosphate from the juices could be encouraging the spike. Another thing to consider, if the prepared foods have fish meal in the first five ingredients, the phosphates could be coming from that! >
  Is an extremely high level of phosphate a possible cause for my losing a number of fish recently, a day or two after acclimation (which I normally do gradually over about 1-1/2 hours)? (It's not due to a mantis shrimp;  there is no clicking, and no sightings at night.)
< I seriously doubt the phosphates would cause that kind of reaction. I would look more at temperature fluctuations, or the possibility of airborne pollutants. >
After talking to a couple of LFS, I'm becoming convinced that the DSB will eventually crash, and I am planning to remove it soon.  How gradually do I have to do that?
< A four inch sand bed is not deep enough to really cause a serious problem, but if you must remove some, only remove an inch or so. Remember, the sand under the first inch layer is horribly toxic. Don't stir up too much! >
My main question has to do with skimming.  I have an Aqua C Remora (not Pro) with the Maxijet 1200 powerhead and overflow box (I have no room for a sump).  One LFS is saying that that is not enough skimming capacity for a 55 g tank.  Currently I have four small fish, a cleanup crew of 20 hermit crabs and 15 snails, four small colonies of mushroom polyps and two small frogspawns, but I hope to add a few more fish and many more corals.  How
much skimming power do I really need with this setup, once the DSB is gone?
< That is directly related to the amount of food you feed, and the frequency of partial water changes. To place exacting limitations, or requirements on such is difficult. >
< Yet another thing to consider is the possibility of your source water or supplements containing phosphates. Be careful when adding anything to buffer the pH, for nearly all related products use phosphate buffering agents! >
Many thanks for all your help
< I hope I was indeed helpful! >
Bob
< RichardB >
"Sponges grow in the ocean. I wonder how much deeper the ocean would be if that didn't happen." ~Steven Wright

DSB's...Adding More Substrate  6/26/06
Hi Crew!
<Hello Brett>
I've decided to beef up my substrate by adding another inch or so to my DSB.
Right now it's about 2-3 inches and am planning to add another inch or so of Arag-Alive Fiji Pink.  Will I be safe adding it all at once, or should I
gradually add the sand over a few days?  
<Should be no problem adding all at once.>
Thanks for any help!
<You're welcome.  James (Salty Dog)>
Brett

DSB   6/9/06
Hey Crew!
Thank you for the great service you provide, don't know what we would do without you all!
I am becoming more confused by the minute.  I spent quite some time researching & thought I had covered all my bases.  I have DSB of 7 inches.  I decided to go w/ depth for a few reasons (filtering, maintenance, & wanting to keep a jawfish).  I read that you were not supposed to disturb a DSB, as it might "crash" the tank.  Now, I am reading that I should "poke" or "stir" the DSB to prevent a "crash".
Can I get your thought on this?  If it does require "poking/stirring", how should this be done and how often?
Again, thank you for the site & any help I can get on this matter.
Take care, Wendy
<<Wendy:  Intentionally stirring up the DSB ruins the whole point of the DSB; namely that you need higher and lower oxygen areas in the DSB to realize the benefits of the DSB.  Best of luck, Roy>>

Re: QT screw up, oh and DSB sand  - 05/13/2006
Thanks again for your reply Bob. The weirdest thing has happened - the ich (or at least what I thought was ich) disappeared from Regal tang
in less than a day. Is that possible?
<Umm, yes... is not really gone... is/has cycled off... your system is infested... and like that not-so-popular ex-Austrian Gov of the Sunshine State, it'll be "baaaaack">
- I guess it could have been micro bubbles but I don't think so  since all I have is small hang on filter and power head as filtration- maybe some sand particles in the QT ( there is no sand bed in the QT)?.
<I suspect you're right here. This was Crypt>
In my other QT, my yellow eye tang has regained its color and the fish seem happy. I am doing a 10% water change in QT every 2-3 days to help the stress levels. Can a FW dip with methylene blue remove ich immediately?
<Not generally...>
That's all I did!! Any ideas ?- Oh well.
On an unrelated matter I have a refugium with a DSB that I had taken offline for a couple of months. I have decided to give more space to the Chaeto so I began to remove my 7 inch sugar fine sand  (to use in my new system) when I noticed some black streaks in the sand and smelled an odor . Can I still reuse the sand and if so do I need to rinse or recycle  it with salt water?
<Best to give this a vigorous rinse at least... the hydrogen sulfide smell should be "all gone" before re-using... though the black stain may well persist. Bob Fenner>
Many thanks again

Deep Sand Bed - 05/11/06
HI, I was wondering if you could tell me the proper way to manage a 5-inch deep sand bed?
THANKS.
<<A rather nebulous question my friend.  Do start reading here (http://www.wetwebmedia.com/deepsandbeds.htm) being sure to follow/read among the links in blue at the top of the page...and feel free to come back with more specific questions if need be.  Regards, EricR>>

Nano DSB  - 04/26/06
I am a huge fan of the DSB and have had great success with it in my 75 gallon reef tank at home (thanks to the info on wetwebmedia.com). I have now started a 24 gallon AquaPod at work so I can enjoy my reef all day.
<Very cool!  I want one at work too!  But just remember – you’re working with a whole different animal here now that you limited your water volume to such a small amount.>
I employed a 4 1/4" oolitic sandbed with 25-30 lbs of LR.
<Sounds nice – however severely limits your volume once again, you will have to be much more careful here, won’t be as forgiving as your 75g>
I also threw in a couple scoops of sand from my DSB at home to seed it with some pods and worms. The tank is stocked with 2 small Chromis, a very small ocellaris and the usual assortment of janitors.
<Just fine amount of bioload here.>
Corals include a pom pom xenia, star polyps, Fungia sp, assorted zoo's, 2 Ricordea yuma, and other various mushrooms. The Nitrate has steadily risen in the AquaPod (unlike my tank at home that has had undetectable levels for almost 2 years) it's currently around 50ppm after 2 months.
<Ouch, much too high here – especially stressful for your inverts.  You have much too much in this tank given its only 2 months old.>
Is the DSB just not deep enough for a volume this small, maybe it needs more time?
<I wouldn’t add anymore sand here, you already have little water.>
I don't think the bioload is anywhere near "too much" fish wise and I feed very sparingly.
<Bioload is fine.>
I run a micron filter pad, changed daily and use RO for top off. I'm planning on buying a little skimmer for it, but don't have great confidence in the cheap ones that can fit in an aquarium like this (current's fission skimmer).
<Absolutely must have a skimmer here.  Personally I’ve found that the fission doesn’t do much.  Adding a sump/refugium with a better skimmer like the Remora, would be the best option.>
Would it be worth slowly adding another inch or so of sand?
<I wouldn’t, no.>
Any ideas are appreciated. For now I'm just going to go back to weekly water changes until I get things figured out.
<Keep up your water changes, it is possible that you haven’t quite cycled completely though.  You’re really high and you have enough in there to add to it daily.  Next time, with a volume so small, I would wait a little longer than you did before adding inverts precisely for this reason.  Good luck, Jen S.>
Thanks so much, Jeremy

Re: nano DSB For Jen S.  4/27/06
Thanks for your reply Jen.
<No problem Jeremy!>
Your right, that is a lot of coral for a 2 month old tank. They have all been frags from my big tank so pretty much free
(it's hard to resist bringing them with me to work!).
<I get you here!>
Anyways, I  just wanted to let you know that if you really do want a nano for work, fostersmith is selling these 24 aquapods on special for only $169(shipping was $13 so its like 25% cheaper than I've seen anywhere) for the next week or 2.
<Thanks for the info – I ALWAYS order from them, but I don’t believe I’ll ever go nano reef tank again (I have a 12gal up and running among others.)  There are just too many mod.s to make to these already built systems.>
They do run a bit hot and we had to mod them with some additional fans in the light cavity and some breathing ports on the outer shell to evaporate the condensation.
<Great mod.s, you should have seen me adding proper lighting to an eclipse hood!>
All and all I am pretty happy with them so far. I'm going to try and shave 1/4 off of a Berlin airlift 60 skimmer nice and quite plus no extra wattage in the tank) crossing my fingers....it should fit in the back chamber.
<Great luck!  I just added a sump/refugium to add the skimmer into, among the many other benefits.  Thanks again for the info!  Jen S.>
Thanks again!
Jeremy

DSB and Confusion(s)  - 04/19/06
Hello to the WWM person of the day!
<Guess that is me, Adam J with you today…..’err tonight.>
  I have a 100gl tank which I purchased recently and when it was moved I saved half the water, as well as most of the sand.
<Okay.>
I set it up as a reef, with 4" DSB, but kept having algae blooms because one powerhead blasted a corner and stirred up the sand too much.
<Common problem with DSB’s.>
At this point I decided to remove a pesky tang and Anthias, which came with the purchase, so having to basically break down the tank to catch them, I moved all the LR to my 40gl tank with no sand bed.
<Okay.>
OK, here's where things get fuzzy...I decided I would like to keep the smaller tank as the reef tank instead.
<All right.>
It has plenty of pods and critters and I want to set it up as a Seahorse exhibit.
<Be sure to research the needs of these creatures, not an endeavour I recommend to just casual aquarists.>
Now for the 100gl...It has been sitting for 3 months with old water, no light, no heat, etc.
<What about flow, was it stagnant.>
I drained nearly all the water, and to my surprise, a few snails (who got left behind), were still moving along in there. With the tank sitting so long with out any attention, is the sand still viable?
<Sure.>
I am planning a FOWLR, so I need to decide what to do with this sand.
<Keep if you want, but once the tank is in “working” order again I would allow a minimum of 30 days to let it stabilize.>
Do I clean the sand entirely with saltwater, remove it completely or just the top layer?
<I would vacuumed any detritus out of it, stirring if necessary since there is no livestock in the tank.>
Would it be usable for the 40gl tank?
<You could, but moving it will disturb the anaerobic pockets, it will cause the “levels” in the 40 gallon to go array…this is fine if their isn’t any livestock in there yet.>
If I want to add sand to make it deeper, would I want to add sand a little at a time or could I put in another inch all across and stir it up a bit? I assume curing any new LR might be done simultaneously.
<That’s what I would do.>
This would all take place before any inhabitants move in,
<Great, that’s what I was concerned about.>
of course. Trying to juggle setting up two DSB's at once is giving me a real headache. Please help me stop the "spinning room" syndrome! Thanks!
<Adam J.>

Re: reusing an old sand bed    4/25/06
Thanks for clearing the confusion Adam.
<He seems to have skipped town...>
No, there is no water flow in the big tank. I'll do as you recommended and simply siphon off the sediment along with stirring up the top layer of sand. As for the 40gl, it does have a couple of fish (a fire fish, plus a small clown who will be returned to the 100gl ), also Xenia, hammer, GS polyps, a feather duster, along with a couple of turbo and Ceriths, hermits and a Choc. chip star (which will go back in the 100gl when its livable). I do have some experience, along with all the research I'm doing, to feel confident making the reef ready for horses. Here's my next question... should I retrofit a DSB with new sand into the 40gl?
<Could... as you'll see/find, I am a big/ger fan of remoting such in separate tied-in sumps/refugiums... much easier to maintain, manipulate>
As mentioned earlier, all the rock and inhabitants were originally placed in there as a holding tank with out any sand bed. I do have plenty of pods and such living in a few clumps of Chaetomorpha (Brillo pad) algae and I've see nano tanks kept without one, but I wouldn't be able to put a fuge on the back.
On a scale of 1-10, which would you opt for? Also, I plan on returning the bio-balls to the big tank's sump, in addition to keeping the DSB. Any concerns?
  Thanks again
<Sorry, don't understand your stated options clearly... I would choose the largest/r 'fuge... place the DSB there. Please read here: http://wetwebmedia.com/marsetupindex2.htm
see the area about four "paragraphs" down on Refugiums? Bob Fenner>

DSB For A Large Tank - 04/09/06
Dear Bob,
<<EricR here this morning...I think Bob is still asleep/recovering from his Lavaman ordeal <grin>.>>
I currently have an 8ft tank and would like to add a deep sand bed to assist in denitrification and to provide more comfort for my stingray.
<<A very good idea in my opinion.  I too have a 8ft tank, with a 6" DSB...but no stingray (is a reef display).>>
I have read the article on the website, and am aware that 3" depth is a minimum.
<<Mmm...can depend on 'grain-size' of the substrate, with larger grain-sizes meaning deeper beds.  But even when using sugar-fine sand my preference is for a 4-inch minimum.>>
There is 40kg of fine coral sand, 12 kg of fine grade aragonite currently in the tank which makes up an average depth of between 1-2 inches.  I will create the DSB by adding sugar fine sand, although I would like your opinion as to how deep I should go?
<<Were it me, with this mix of sand, I would shoot for an absolute minimum depth of 4 inches...even 5 or 6 inches if your not opposed to the look/loss of depth to the open water column.
I know that bigger tanks require deeper sand beds.
<<Not sure I agree with this.  All things equal, the sand bed will be proportionately larger in the larger tank.  As far as I'm concerned, 'minimum' bed depths would apply equally to all tank sizes.>>
Current inhabitants included a small masked-stingray, 3 snowflakes.
<<Sounds like a very nice display.  This ray (Dasyatis kuhlii) seems to be one of the better choices for aquariums (not to be confused with Taeniura lymna...another/different 'blue-spotted' ray with a very poor survival record) and will definitely appreciate a 'fine' sand bed.>>
Also, I have attached a spare 10g tank as a refugium (which I know is small, but at least it puts the tank to good use) and would also like to know if creating a deep sand bed in there, without having a DSB in the main display, would have any sort of effect on denitrification?
<<Probably not a noticeable effect...considering the size/stock list of the display.  I think putting the DSB in the display is your best option.>>
I'm just trying to get my head around the proportionate area of DSB and its correlation to the degree of denitrification.
<<Please have a look here:  http://www.wetwebmedia.com/deepsandbeds.htm >>
Thanks in advance,
Joe
<<Quite welcome.  Regards, EricR>>