FAQs on Freshwater Aquarium Filtration Involving Sumps, Refugiums

FAQs on Freshwater Aquarium Filtration Involving Sumps, Refugiums

Ammonia, Nitrite & Nitrate Units of Measure 4/10/18
Hello Crew,
<Hey Ray>
I have a 210g, probably considered overstocked, mixed Malawi tank. The tank is filtered by a submerged media sump with a six times turnover. I use Hanna meters for my chemistry checks. The ammonia, nitrite and nitrate
meters all measure using the -N unit of measure (NH3-N, NO2-N & NO3-N).
The unit of measure for ammonia and nitrite are not relevant since the goal of both is to maintain 0ppm. Nitrate is the one causing me some thought. The tank consistently runs 10 - 30ppm NO3-N and I use this value to determine water changes, as it approaches 30ppm I do a 50% WC usually every other week. But if I apply the conversion factor (4.4) to these numbers my ranges are 45 - 130ppm in which case my WCs should be happening probably twice per week. I recently read the article, Nitrates in Freshwater Aquarium Systems
by Bob Fenner, which stated "Do check your test kit though almost all are nitrate ion types on the market nowadays..." I'm guessing doing the conversion on NO3-N > NO3 is what I should be looking at.
<Yes; agreed>
The tank has been running in its current configuration (mixed Malawi) for 2 years, before that it was a planted discus tank for maybe 8 years. Being retired gives me time to think, maybe too much. Should I take the attitude, "if it ain't broke, don't fix it?" Looking for confirmation/disagreement.
Thanks,
Raymond M Sugel Sr
<Were it me, mine, I would increase the number/frequency of water changes as you state (twice a week; with pre-mixed (for pH, salts if you use them) stored water. I encourage you to look into the possibility of tying this
tank in with a good size/volume sump as well, perhaps growing live plants there, incorporating a deep sand bed for denitrification; utilizing and out-gassing the excess NO3. Bob Fenner>

Re: Ammonia, Nitrite & Nitrate Units of Measure; now sump design 4/11/18
Thanks for the response Bob.
<Welcome Ray>
The tank currently uses a 50g sump for filtration, will be up-sized to a custom 120g sump next week (being
delivered tomorrow) (drawing attached).

As you can see the water flow pattern I designed doesn't give me an area for a deep sand bed/refugium.
<Mmm; if you change your mind later, you can/I would substitute the current mid area for a DSB and live plant culture/refugium... with a RDP lighting arrangement (alternating from your main/display light regimen)>
I have researched using an external "aquaponics" set up. From what I have read Pothos is the commonly used plant but it is toxic to cats (wife has a couple of them). Just need to find a plant that will work in an aquaponics
system, takes up nitrates as well as Pothos but isn't toxic for other critters.
<There are several choices; including many of "aquarium" plants that really grow best in the air>
My other thought was to use a continuous water change system. I use a 100g storage tank where I pre-treat RO water. I'm on a well that I like to describe as "flowing rock." Its GH is around 700ppm but KH is only 10ppm.
<Interesting; we have high KH and GH water here in much of S. Cal.>
I could set up a continuous change of 1gph, the storage tank would last 4 days and the 5th day for refilling the tank.
<Really sounds great for your Malawi set up... do assure me that you will have safeguard/s, alternative overflow discharge/s for potential
overflowing here>
Raymond M Sugel Sr
<Bob Fenner>

Substrate for my fresh Water refugium 1/10/17
The
<The? Is there previous correspondence?>
substrate is made of organic potting mix (no fertilizers, at least as written on a bag)
<I'd be testing... by soaking, perhaps boiling a teaspoon or two in some water... testing the liquid>
- about 2 inch thick,
<?! This is a BUNCH of material; too likely to "float out"... a mess. I'd be mixing the soil with fine gravel...>
.5 inch of fine gravel op top of soil and 1-1.5 inch of smooth white sand (not aragonite) Do you have a tip,
<A tip? I'd be doing more searching here... on WWM, the Krib... Diana Walstad's works; maybe Takashi Amano. What you have done here so far?... Not viable>
I set up a fresh water refugium for plants and fry. I bought a bag of organic potting mix from Menards and put it in the middle chamber and it just floats.
<Oh yes; assuredly>
Above is from a blog I got from your site and read the same from others.
<Can't tell what is lifted without quotation marks, notes... Maybe have someone else read what you send out ahead of time to assure it makes sense.
Bob Fenner>

Freshwater refugium experiment 6/3/16
Hello! I know freshwater refugium questions pop up from time to time so I thought I'd share my current fw refugium experiment with you.
<Thank you>
I had an Aquafuge hob refugium left over from a previous saltwater tank, which I have set up on my 29 gallon freshwater dirt substrate planted aquarium. It's been in place for a couple of months now. It's set up a lot like the main tank, having a dirt substrate capped with fine gravel and plants (Bacopa and red Ludwigia). The refugium has its own light for the plants.
<Do you alternate the light cycles here?>
I added some Gammarus to both the refugium and the main tank. About a month ago I was feeding some live blackworms so I also added some of those to the refugium. They are still alive and doing well. I know they can
reproduce by fragmentation, I'm still not sure if fragments from the refugium colony will make it to the main tank or if I'll have to harvest them somehow. At the time I added them I was just curious to see if they would thrive in the refugium over time. There are also some Ramshorn snails (the pretty pink ones) and tadpole snails in the refugium. They are also in the main tank but the main tank has assassin snails and two pea puffers so the refugium snails are there to replenish the tank population if / when needed. A few times a week I drop in some veggies or a few algae tabs for the snails. The snails are all doing really well in there.
Recently the tank developed a bit of green water, which gave me the idea of adding some daphnia to the refugium. I got a culture of Russian red daphnia and put about half of them in a regular daphnia culture jar, the rest went into the refugium. This was very recent so it's still uncertain what will happen with them longer term. My hope is that they
will multiply in the refugium, thus taking care of the green water and also supplying some live food to the tank inhabitants.
<A good idea>
I tried putting some cherry shrimp in there to see how they would do but that didn't work out. They like to swim around a lot, and one by one they swam too near the overflow and got sucked and washed out into the main tank. I guess I could fit a piece of screen over the overflow but that might defeat the purpose of supplying occasional Gammarus, daphnia, etc. to the main tank.
So now I'm wondering what other foods might be cultured in there. Any ideas?

What do you think about the daphnia, any chance they can form a long term culture in this setup?
<Some; yes. I'd run an alternate culture in a "kiddie pool" or such outside or in the garage.>
Thanks for your interest,
Joanne
<Thank you again for sharing. Bob Fenner>

Questions regarding Plumbing in 125 Gallon Freshwater Build with Sump... reading 4/1/14>
Hello WWM crew,
<Michael>
This is my first attempt at a sump system (have owned 30 gallon and 55 gallon freshwater tanks in the past, but using canister filters). Trying to
make more room for my freshwater angels, I picked up a 125 gallon DT/55 gallon ST and stand on Craigslist and have slowly been updating and planning its design. Doing research online has provided me with answers to a lot of my questions, but I'm a little out of my depth on this matter of plumbing. I'm not afraid to attempt to plumb the tank myself, but I'm just not certain about all the factors involved. I was hoping I could share my schematic with you guys and maybe you could make a recommendation or two.
<Sure>
Here it is in its current form. All of the illustrated plumbing is 1" PVC (Schedule 40)
<Mmm; I'd make the overflows likely 1.5" inside diameter. Do you want help finding the articles and FAQs re on WWM?>
except for the return lines in the overflow (above the bulkheads) which are 3/4". Additionally, the plumbing for the UV Sterilizer is 3/4" (didn't figure it would need 1" since it isn't pushing the kind of volume the return lines are). The pipes filled with green are the return pipes. The red pipes are drain pipes. The neon green pipe is dedicated to the UV sterilizer.
A few system notes regarding accessories I've acquired so far:
-The media cabinet/BioWheel is a Tidepool 2 that I cut the front section off of. I just wanted it for the BioWheel and the media cabinet, so I didn't have to build those things from scratch (also got a good deal on the thing at a local aquarium store)
-The pump is a Fluval SP4, which
nominally pushes 1823 GPH at 0', 1672 GPH at 1'6", 1548 GPH at 3', 1347 GPH at 4'6", 1281 GPH at 5'9", 1135 GPH at 7'2", 805 GPH at 9'5", 499 GPH at 10'8".
<Uhh, yes... the 1" lines won't accommodate this flow>
Sadly, I can't return this even though it's new merchandise due to the shifty business practices of the store owner (won't be shopping there again, but doesn't help much in this situation), so I really hope I can make this pump work with the system.
<You can>
-Standpipes are Hofer Gargle Buster design.
<http://home.everestkc.net/jrobertson57268/HGB/>
-Coralife TurboTwist 6x 18W UV Sterilizer
So my primary question involves the plumbing itself. I assume the layout presented will be workable (and I apologize if the diagram isn't clear; would have been vastly better if I'd had time to do a top view as well).
All my plumbing is 1" schedule 40 except the supply pipes ABOVE the bulkhead, and the UV sterilizer plumbing, which is all 3/4"). I'm concerned as to whether or not 1" will have sufficient throughput to keep up with the pump and gravity fed drains.
<They are not. Do read here:
http://wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm
The holes drilled through the tank were already done when I bought the tank, and measure 1 7/16" and 1 3/4", allowing for one 1" bulkhead and one 3/4" bulkhead in each overflow.
<Have these re-drilled. Do NOT rely on siphoning here>
My other question is something that I've gotten many opinions on, just hoped maybe I could get one from you guys. How to seal the plumbing that interfaces directly with the bulkheads?
<The bulkheads/through-puts have threaded throats... and gaskets... Use a bit of Silastic on both sides... will seal, yet allow removal at some later stage... the PVC to PVC slip joints should be primed and solvented... the thread to thread connections can be best put together w/ a bit of silicone lube fingered on the threads>
As illustrated, basically every joint in this system is going to be solvent welded with PVC cement (except the ones connected to pumps and accessories). Since I can't fit Union Joints beneath
all the bulkheads I figure I'm going to have to saw everything off if I ever have to remove the plumbing anyway,
<Mmm; not necessarily; no. READ the linked files above the citation; ask for some local fish-hobbyist help... and consider the use of a few
true-union fittings>
so I didn't know if it was worth it to use nylon tape on these particular joints.
<Not really; no... again, the smear of Silicone lube, even Silastic>
Some people have said to solvent weld those joints, others have suggested a small amount of silicone as being easier to remove if needed, but more reliable long-term than nylon tape. Any thoughts?
<As stated>
Thank you so much for your time and expertise.
Michael in Overland Park, Kansas
<Welcome. Bob Fenner down in Cozumel, Mexico>

Re: Questions regarding Plumbing in 125 Gallon Freshwater Build with Sump 4/2/14
Wow, glad I checked in with you guys before I went ahead with this build. I wish I'd found those articles you pointed out months ago, could have saved me a lot of grief and resolved a lot of elaborate planning more efficiently. Seems as if most of my questions were addressed in just a few of those articles. Thank you very much for enlightening me.
Michael
<Glad to share... you could of course, just greatly reduce the rate of flow... through the one inch return lines... and supply recirculation water flow via internal pumps, powerheads... Cheers, BobF>

Sump for a freshwater tank? 12/31/13
Happy new year to all you wonderful people!
<And you Tim>
I've had three smallish reef tanks for four years now, great fun, but I'm looking to expand my horizons. I'm planning my first ever freshwater tank, 90 gallons and heavily planted. I've read three books on the subject so far and ordered a few more. I'm also but steadily working through the vast material here. But there is one vital setup issue that confuses me, and I hope for some wisdom from you.
<Ok>
Every book I've read and every tank I've seen uses a solid tank, with filtration done by under-gravel, hang-ons, or whatever. Nobody takes the traditional marine route of having a drilled tank with sump below.
<Oh; some folks do; have done so>
To me that's a no-brainer. I could keep the heater in the sump, pump water for the chiller from it, and maybe even rig some kind of filtration to avoid ugly hang-ons. But it makes me nervous that nobody seems to do that.
Am I missing something important? Thanks for any advice!
Tim
<Sumps can function for freshwater systems in all the way they do for marine. A bit more archived here re:
http://www.wetwebmedia.com/FWSubWebIndex/fwrefugiumfaqs.htm
Bob Fenner>

Refugium and aeration 4/27/13
Hello crew!
<Josh>
First time writer, long time reader. Great website! I have a 125 gallon long aquarium, heavily planted with co2 system, 35 gallon refugium fed from CPR overflow box and a Fluval fx 5 canister. I currently have a silly volcano in the center (my girlfriends only request) pushing out these huge bubbles that agitate the surface. My question is this- Will the refugium with overflow box cause enough aeration below the tank to keep oxygen levels adequate or must I have an air source in addition? I really want to eliminate the enormous volcanic bubbles. Also, I have the return from the Fluval pointed up to create a good amount of surface movement. Current stock load is about 20 tetras, 6-8 Cory's, 4 bushy nose Pleco and 8 discus in transit. Please help! Thank you in advance for your time and consideration.
-Josh-
<I think you likely have enough surface agitation with the overflow unless you live in a very hot climate, but do be prepared to act if the fish show signs of oxygen deprivation. You might consider replacing the volcano with a sponge filter. Personally, I love sponge filters because you get surface agitation and you get additional mechanical and biological filtration.
Clean water is important for the discus and Plecos are somewhat messy.- Rick>

Tapped sump? FW design 11/12/12
First off, thank you for your awesome webpage, I've spent literally weeks reading the questions and answers in your forum and have learned huge amounts here. I'm writing because I'm considering setting up a new aquarium with a filter sump and I have a couple of ideas which I think could be useful, but which I can't find any examples of on the internet.
I'm trying to decide if the reason is that the ideas are original, or if they've been tried and failed.

First off I'd like to place the sump beside the aquarium instead of beneath it so that the water level of the first chamber is the same as the water level of the aquarium.
<Mmm, okay. How will the water get from one container back/forth to the other?>
The first chamber would then be a settling chamber, where hopefully most of the muck would settle out of the water before it gets trapped by the filter. That first chamber would also be drilled at the bottom and given a tap so that I could place a watering can underneath it,
<Mmm, unless there is a sort of funnel shape to the bottom, better to just count on periodic siphoning to clean this settling chamber area>
open the tap and drain 10 liters of water plus mulm for watering my house plants.
<Ahh, freshwater then>
The hope being that with undergravel jets I could also make sure most of the mulm gets to the sump.
<Likely so>
I know that wouldn't be enough water change to take care of nitrates, but I'm also playing around with a couple of other ideas for that (continuous automatic water change system and aquaponics sound really cool, but it could be that I'm still too far into the pie-in-the-sky phase of planning a cool project :o)
<Good to dream, plan though>
So my questions are: 1.) Is there a reason all the sumps I'm seeing are beneath the aquarium?
<Mmm, a few; easier/est to provide for (gravity) feed, and nicer to keep out of view mostly>
Can a sump be placed beside the aquarium and still "pull" water from the aquarium well enough?
<IF the water flow rate is slow enough (pumping from one or the other, allowing water through a mechanism (siphon/less desirable, or through-put/s/more desirable) sufficiently>
2.) Placing a tap in the settling chamber of a sump seems so blindingly obvious to me, that there must be some reason I can't find a picture or comment from someone who's done it. What problem am I missing?
<Just the application for freshwater systems (rare); these sorts of traps are common in well-designed and built (Koi) ponds.
Bob Fenner>
Thank you,
Myrle
Re: Tapped sump? FW 11/13/12
Thank you Bob,
>Welcome Myrle<
<Mmm, unless there is a sort of funnel shape to the bottom, better to just count on periodic siphoning to clean this settling chamber area>
OK.
<Mmm, okay. How will the water get from one container back/forth to the other?>
I'd pump it out of the sump mostly into the right side of the aquarium and let it "fall" back into the sump through a drilled out hole in the left side of the aquarium. I'm staying away from a siphon for the job.
>I think you're wise here... I believe in gravity... though it's always (bad pun coming) let me down. Do have a large through-put diameter in both tanks (1.5", really)... and not too-high a flow rate and you should be fine here<
I have no need to take that risk. Thinking about it, I probably shouldn't place the aquarium and the sump too close to each other because the plumbing connecting the two would need to be somewhat flexible to avoid causing a leak.
>Mmm, the flex PVC to rigid through puts is a good idea<
Thank you for your time. I appreciate the tips. (By the way I especially liked your websites tips on creating a natural-looking aquarium: http://www.wetwebmedia.com/fwsubwebindex/aqscabegart.htm)
>Ahh, danke<
Greets from Germany,
Myrle
>Choos, BobF<

Freshwater sump – 4/19/12
Dear Wwm.
Will installing a sump filled with fast growing plants, on my planted freshwater tank.
<This will likely drive off CO2. Anything that splashes water, or mixes it with air, will drive off CO2.>
And reversing the day/night cycle (like a reef system)
<Why? For plants, day length and light intensity are all that matter.>
Would this improve the co2 level in both tank. And is there any other benefits?
Thank you
From Phil's i4
<Making life too complicated for yourself, I fear. Focus on providing the best possible (usually: strongest) lighting you can. Then, at the least minimise CO2 loss, and ideally, provide extra CO2 through an automated CO2 dosing system. Do understand many plants grow just fine without extra CO2 and some, like Vallisneria, can use bicarbonate from the water instead, if needs be, which is why they LOVE hard water. Cheers, Neale.>

suggestions for "side" sump 9/22/11
I have a 60 gal saltwater tank, fish only with some live rock and a few invertebrates.
I had the tank made years ago and I divided 20% into a "side sump". It recently started leaking so I ordered a new one made. On retrospect, I probably should have reconsidered the design first but because of the leak - and the tank is in my office - I rushed to get a new one.
The water from the tank (and also from a hang-on skimmer) feed into the side sump and then is pumped back through a pipe (I had a hole drilled at the bottom of the divider), to the other side of the tank. So I have nice circulation.
Attached are two photos.

Till now I had the water flow into a refugium and then overflow into a column filled with Seachem matrix and then the water was pumped back into the tank.
I was thinking of changing this. I asked the tech support at Seachem and they said the matrix works best submerged (as opposed to bio balls).
<This is so>
Any comments or suggestions on the set-up? I would love to get your feedback.
<Feedback...? What you have can be made to work. Am a much bigger fan of independent sumps for looks and functional reasons... but space-limiting situations...>
Also, what's your opinion about a sump (filled with matrix pond), on a 150 gal fresh water tank (as you can guess, use to be for sw but needed to make life a bit easier so I switched to fw).
<I'd go another route myself, maybe using the Matrix product in a contactor capacity, utilizing a DSB and refugium area w/ live plant culture on a RDP schedule to the main tank>
Thanks in advance. I really appreciate and enjoy your site.
Mark
<Thank you, Bob Fenner>
Re: suggestions for "side" sump 9/22/11
Bob,

Thanks for your speedy reply. Regarding my last question, I was talking about a 150 gal fresh water tank.
<Yes; I understood this to be the case>
People use a refugium with fresh water?
<Indeed they do... Please see here for a bit re:
http://wetwebmedia.com/FWSubWebIndex/fwrefugiumfaqs.htm
Cheers, BobF>
Thanks for your help.
Mark
Re fresh water sump 9/23/11
So for a fresh water sump, the most beneficial and logical order would be, first the water would flow through floss for a gross mechanical filtration, then into a refugium with DSB and then through matrix/matrix pond?
That makes sense?
<Ah yes>
And one thing I always wondered, just having bio balls float in a sump with a heavy flow, does that do any good or just a waste of space?
<Some good, though for highly variably loaded (metabolically... think of more/less bio.) systems, aerating them... splashing in air with water, is more effective/efficient in driving nitrification>
Again many thanks. On my way to Eilat now to dive. Need anything?
<Enjoy! If the olde and new kibbutzim hotels are there, choose the latter! Shalom, BobF>
Re: fresh water sump
Shana Tova
<L'shanah tovah tikatev v'taihatem my friend. BobF>
Re: fresh water sump 9/24/11
Amen and one last question. Should I bring back some sand from Eilat to help seed my new refugium?
Mark
<No my friend. Enjoy your journey. B>

Fresh Water Live Rock 6/25/10
Hello all:
<Hi Richard,>
I am writing to you today as I am preparing to redo a 38 gallon fresh water aquarium that's going to be home to a few cichlids.
<Do bear in mind this is a VERY small aquarium for our cichlid friends; unless you're planning on a harem of Apistogramma or some other Dwarf Cichlids, a 38 gallon tank is essentially adequate for just a pair of medium-sized cichlids, for example a pair of Keyhole cichlids, plus some dither fish and catfish. Don't even THINK about Mbuna -- this tank is way too small for them. There are some Tanganyikan fish that'd work, but they're not so easy to obtain as the usual (usually hybrid) Mbuna sold in pet stores.>
I plan on removing the hang on back filter/powerhead and replacing with a custom built in filter of my imagination and creation.
<Okay.>
I want to use acrylic pieces to make a separate enclosure that runs the entire length of the back of the aquarium with approximately 25% total system volume. The water would enter on one side by surface skimming,
<Be careful with this... some cichlids are notorious "jumpers" and will be almost suicidal in their attempts to get through slots and other openings.>
travel through the filter, then exit on the opposite side by submersible pump. My question is what to put inside the filter.
<Most anything, but veering towards biological filtration plus some mechanical filtration to keep the water clear.>
I plan on having a spot by the pump to place carbon bags. I have some dry base rock intended for salt water use that I would like to put into the tank and filter and give it time to become alive.
<This is the bit that makes me nervous. Limestone such as that used for marine aquaria will harden the water, and as I stated above, this tank is far too small for almost any Malawian cichlid and the majority of Tanganyikan cichlids. Really, apart from dwarf Julidochromis and Neolamprologus, your sensible choices in a tank this small are all West African or South American species -- and these WILL NOT appreciate hard water.>
I would also like to place that rock that's in the filter onto a deep sand bed about six inches deep.
<A freshwater deep sand bed is certainly possible; see here:
http://www.wetwebmedia.com/ca/volume_7/volume_7_1/dsb.html
>
Would this work for fresh water fish only environments?
<It is certainly possible to create denitrification in freshwater tanks, whether via DSBs or live rock. The question is whether it's worth doing. Bear in mind plants do a much better job of nitrate removal than live rock, and growing plants in freshwater tanks is easy, much easier than growing seagrasses or macro algae in marine tanks. So usually adding clumps of fast-growing floating plants or whatever will do a much better job of denitrification. Secondly, stocking densities are usually much higher in freshwater tanks than marine tanks. So in freshwater tanks the main way to remove nitrate is water changes, since denitrification just isn't fast enough to handle the nitrate in a heavily stocked aquarium.>
Would I be better off just putting some plastic media into the filter?
<Good quality ceramic noodles plus some bioballs generally works very well>
If the rock and sand will work, should mechanical filtration be taken into account before the water enters the live rock / deep sand bed portion of the filter?
<No; you need some sort of pre-filter through floss or whatever beforehand.>
Thank you all for your time.
Richard
<Cheers, Neale.>

Re: Fresh Water Live Rock 7/1/10
Wet Web Crew:
<Richard,>
Thank you for your reply. As you hear a lot, the answer has led to more questions.
<Indeed.>
First, I have purchased a 55 gallon tank with a reverse flow under gravel filter
<Incompatible with rockwork, so cannot be used with rock-dwelling cichlids like Mbuna.>
for the fish and I will use the 38 gallon as a sump.
<Okay. Now, do understand that if you are still dead-set on Mbuna, that they are interested in SURFACE AREA length x width) not capacity. So while the 55 gallon tank with a 38 gallon sump makes water quality management
much easier, you're still stocking as per a 55 gallon tank, and for Mbuna, that's still very little. I do hope you'll do the sensible thing and look at alternative cichlid ideas. For example, there are any number of lovely Julidochromis, Neolamprologus and Lamprologus species from Tanganyika that would work great in a tank this size.>
The 38 gallon will house the pump, some undetermined yet biomedia, and a planted sand bed. I didn't realize the fish were cramped.
<Do understand that Mbuna are fiercely territorial. They demand space on the rocks. Fish that can't hide in the rocks because they can't hold a territory will be sitting targets, and usually end up battered or killed outright. In the upcoming WWM online magazine Mary Bailey has an excellent article on these fish and how to calculate stocking levels for them. It should be out in the next week or two, so check back at WWM regularly.
Without giving too much away, one of the key things she states is that the upper limit for Mbuna is about 24 inches of fish per square foot of surface area, assuming the tank is mostly rockwork. She goes on to explain why a 55
gallon tank is the absolute minimum for Mbuna, and why not all types of Mbuna, let along all types of Malawian cichlid, can be kept together. You have to make a lot of hard choices. If you fail to make those choices up front, the fish will take care of things by the aggressive species killing off the less aggressive ones. Simple as that.>
Thanks. We have hard water where we live. My question is what type of rock can I add to the tank to gain some filtration value, aesthetic value, hidey holes, and won't tweak the water quality too badly?
<Look for rocks that serve one particular task well rather than trying to do all of them. Trying that would be a waste of time. Your choices of rocks is vast. Some aquarists use a limestone called Tufa rock, which is lightweight, relatively inexpensive, and buffers the water. Others like Texas Holey Rock, another type of limestone. Plain vanilla limestone slabs and cobbles work well, but they're heavier, and consequently more expensive. On the other hand, I think they look much more attractive than the white Tufa and Texas rocks, which to my eyes always look bright and ugly (like a failed marine aquarium). When I kept these cichlids I used inert Aberdeenshire pink and silver granites, which looked amazing, but were very heavy and did nothing for water chemistry. A friend of mine used lava rock, which doesn't buffer the water but is lightweight and easy to use. Really, just visit garden centres, see what's available, and provided the rock lacks metal seams and is quoted as safe for water gardens and ponds, it should be safe to use. If you have hard water and -- I recommend this, you add home-made Rift Valley salt mix to each bucket of water -- the use or otherwise of limestone rock isn't all that important.
http://www.wetwebmedia.com/fwsubwebindex/fwh2oquality.htm
Of course do remember that other Malawian cichlids are not rock dwellers.
Some use rocks only for shelter, like Aulonocara, and mostly swim in the open water. You can't keep them with Mbuna as I hope you know, but they're colourful, relatively peaceful, and in many ways much better aquarium fish.>
Thanks again for your help.
Richard
<Cheers, Neale.>

Sump/Filter for Clariid Catfish Farm -- 01/29/10
Dear WetWeb Crew
<Hello!>
How are you? Hope all is well.
<Can't complain.>
I need some help I'm stuck I've never designed a sump before and I would appreciate some help. I am building a catfish hatchery (Clarias gariepinus) so it needs to be fairly heavy duty and handle lots of organic waste products produce by the adult female cat fish while they are in their spawning tanks.
<Indeed! These are very messy fish, and to have acceptable growth rates to be economically viable, Clarias ponds need to be well filtered.>
And I also need one for the eggs to keep the water at optimum levels. I am pushed for space so I am sending you a drawing which I had in mind which may or may not work you are the best that can advise me. I have 2 separate 5 metre by 5 metre rooms to work with, so a separate sump for each.
<Yes, you will need some sort of cover to stop catfish getting out. Clarias are "jumpy" and well known for escaping from their tanks. In Florida they are called Walking Catfish because of this. You will also need to make sure the overflow into the sump has suitable covers, otherwise the catfish WILL wriggle into it and down into the sump.>
Any advice would be appreciated

Kind regards
Yasi
<Cheers, Neale.>

Re: Sump design... Clariids... -- 01/30/10
Hi
<Yasfir>
Erm I was hoping for some sort of help with my diagram, maybe a few pointers on how to actually build a sump? This Sump will not be linked to Ponds But to breeding tanks in which females are isolated so they can receive a hormone injection and then produce eggs which will then be moved to separate tanks were they will hopefully hatch. I need to filter about 8 cylindrical tanks all linked in series with a diameter of 50cm and a length of 1m. I hope this gives an idea of the volume of water in the system I had hoped to build a 2m by 50cm by 50cm sump.
with a trickle tower but I am not sure if this is possible.
Cheers
Yasi
<Are all possible. Much background for you here: http://wetwebmedia.com/marsetupindex2.htm
Though the files specify saltwater/marine, the principles apply to fresh. Bob Fenner>

Cleaning prefilter floss in wet/dry filter 9/10/09
Thanks for your quite helpful and informative website, there is so much useful information!
<Kind of you to say so.>
To learn about wet dry filters, I have setup a makeshift wet/dry filter by pumping water up out of the tank into a container that the water can drip through. You note that the pre-filter should probably be cleaned with tap water (i.e. with chlorinated water).
<To rinse away dust, yes.>
I am worried after cleaning the residual water and chemicals will affect the filter.
<Not normally a problem.>
What do people normally do? Do they clean in tap water and just plonk the floss back in?
<Pretty much. The volume of chlorinated water on the filter floss compared to the volume of dechlorinated water in the aquarium will be trivially small.>
Or rinse it again with non chlorinated water? Or something else I don't know about?
<You could certainly rinse it in a some dechlorinated water if you wanted.>
In case its relevant this is a freshwater tank with a large number of Corydoras duplicareus, the pre filter gets really dirty within a few days.
(I have a large number of babies which I need to on sell soon).
<Nice catfish!>
Either way this wet/dry filter has drastically improved the tank water quality.
Thanks!
Jacob
<Hope this helps, Neale.>

Freshwater Sump??? 7/10/08 Hello...I feel like I should know all y'all on a first name basis, I read constantly on your awesome site and have learned sooo much...I work in the fish department of my LFS and take my laptop to work with me so if a customer has questions I cannot answer, I can immediately go to WWM to look for the correct solution for them. I have recently bought a 125 All-Glass system and am planning on setting it up as a planted tank for Dwarf SA Cichlids, such as Apistogrammas, Borleyii (sp?) and German Rams. From what I have read and understood, these species should get along well in a tank of this size with lots of plants and bogwood and rock. Ok, my concern is this... This tank is pre-drilled as I had originally purchased it to set up as a reef tank, but have since changed my mind since I already have a 90 gal reef. Can a sump be utilized with a planted tank? I looked and looked in your freshwater filtration section and either overlooked it or overlooked it. I can think of no reason not to use the sump but then I don't have the answers...I am one of those misleading LFS people, you know!!! Eagerly await your reply, Thanks in advance for being there and making your site and yourselves available to all of us, I have typed up sheets of paper with wetwebmedia.com on it and cut it up into slips that I give to customers so they can have access to your wonderful site. Thanks again for being there. Rj <Greetings, and thanks for the kind words. There is nothing wrong with use sump-equipped tanks in freshwater aquaria. Works very well in fact, providing more space for biological filtration or the use of calcareous rubble to raise carbonate hardness required for Rift Valley cichlids. The only real issue is that the more splashing there is, the more CO2 is driven off, and this can cause you problems if you are using CO2 in a planted tank. Now, one observation I will make is that Mikrogeophagus ramirezi (such as "German Blue Rams") are not compatible with Apistogramma. There are several issues, but the two most important are differences in preferred temperature and differences in water chemistry. Apistogramma prefer moderate temperature (around 24-26 C) and slightly acidic to neutral, soft to moderately hard water depending on the species. By contrast Mikrogeophagus ramirezi does not do well in anything other than hot (around 28 C) water that is very soft and acidic. The mortality rate of Mikrogeophagus ramirezi is incredibly high in captivity, and I simply don't recommend them any more unless you have a special "hot" aquarium for them and can source locally bred or wild-caught stock. So either stick with your Apistogramma, or else add something like the wonderfully reliable Bolivian Ram Mikrogeophagus altispinosus. Cheers, Neale.>

Beginner Chiller Questions/ Freshwater Refugium Qs 5/11/08 Bob, <Scott V. with you, Bob is out and about without web service.> Thank you again for the help on this topic. I'm sorry to revive it after you suggested not to use one but... I think, after experimenting with fans and frozen two-liter bottles, over the past two weeks, that I am planning on getting a chiller. A couple reasons why: I am planning on adding a refugium to the system. This will add more heat with the pump (40W Quiet One 3000 pump if that's an ok pump by your standards) and lighting. I'm going to get a twin-tube SO 15W-per-bulb light for the 20H refugium and stagger the lighting so it's on when my tank lights are off. I plan on only growing algae and Anacharis in this tank, which are doing really well with my triple-tube SO light in my main tank right now. Also, here's another reason why: I don't necessarily trust anyone to take care of my tank while I'm gone for over a week and a half. I can give instructions to feed, but requiring them to watch the temperature closely is just out of the question. <Yes.> So, I'd rather have a system do it for me. Does this make sense? <Yes.> I know you still probably think I don't need one, but I've been struggling whether or not to get one. I don't feel comfortable without one for some reason. <It certainly will not hurt anything 'except your pocketbook!> It's kind of like when I bought my heaters... most the time I don't need them, but they save me a lot on heating costs in the winter when I don't have my heat on at all in the apartment and it rarely gets above 66F in here. My biggest problem right now is sizing. I used the JBJ sizing chart, and it is stating that I'm between .09 and .14 HP needed. So of course it's recommending the 1/5th (.20) HP chiller. My biggest concern is that this might be cutting it close and the chiller will run a lot. The next highest size is 1/4th (.25) HP. <The 1/5 will do it.> My biggest concern with that is short-cycling the chiller. <This is very detrimental to the life of the chiller.> I'm at my wits end because I don't think I know enough about which chiller is properly sized. They are only about $60 difference, so pricing there isn't too much of a concern. But I do know this is one case where bigger isn't always better, <Nope> but at the same time I want one that can be big enough to handle either a larger system in the future or potentially get me started on salt if I decide to go that way. <A larger, possibly reef system does change things considerably. But, I do feel the Â¼ will cycle on and off too fast for what you are looking to do, it may not have enough of a lifespan to see the larger marine tank.> Decisions, decisions... For the second half of my e-mail... I'll phrase it like a separate email so if you needed you can split it into the different FAQs. I'm going to be setting up a refugium for my 75 gallon freshwater tank. I will not be drilling, and the tank is not reef-ready, so I will be getting an overflow box. <OK, if you intend to use a continuous siphon HOB overflow, do consider two for redundancy.> I'm not sure what exactly I'm going to buy yet. Do I need to use PVC for plumbing the system? <Generally, yes.> I wanted to somehow control the water flow out of the tank, so I know I need some kind of ball valve for the output to the refugium to prevent rapid water flow, correct? <No, you do not want to restrict what flows out of the tank via any overflow in any way what so ever. You will want to control the flow into the tank by putting a ball valve on the output of your sump return pump.> Next, I was going to use a Quiet One 3000 pump to use as the return. I have about 4.5 ft of head to overcome just from the floor to the top of the tank, and adding in any additional resistance from something like a chiller and elbows if it is hard-plumbed needs to be added. This pump has 10ft of head at 0 flow. For the refugium, I'm confused what I should put in there. I know my heaters will go in there, but what about air stones? <You can, air stones will not be necessary with appropriate stocking. The sump/overflow will provide extra O2 exchange.> What about the canister filter? I keep that on the main tank, right? <You can, or provide biological filtration within the sump. Either or'¦> I can only think that it should go in the main tank because it's main function is to clear the tank... but again I'm new to this and reading the FAQs and set-up guide didn't really get into these specifics. I think because most people use a sump as the filter with a refugium built in or separate. In my case, however, I need a relatively low flow through the chiller and the refugium that I have decided to skip the sump all together as I already have the canister filter and have no want to modify the 20H tank I am going to use for the refugium. <Sounds fine.> Any advice or help you can give me is, as always, greatly appreciated. <You are on track other than the points mentioned above.> I think I've got so many decisions to make that I'm complicating everything and I just need someone who knows this stuff to bounce ideas off of. <Happens to all of us entering new hobbies!> John <Have fun with this, Scott V.>
Re: Beginner Chiller Questions /Freshwater Refugium Qs 5/11/08 Scott, Thank you very much for the quick reply. <Welcome.> You are now the second professional that has told me not to use a chiller, and both from this site. I value all of your opinions very much, for you are out here giving us free advice about things you know and love. <We do love and live the advice we give.> So, that being said, please forgive me, as I intend not to challenge either one of your opinions, but rather seek to understand why and how. <No problem, we are here to help others understand what we have learned!> This is due to the engineering/science background that I have. <Me too, I am the same way.> Why don't you think I need a chiller for such high temps? I know the tank will reach 90 degrees over the week and a half I'm gone. Please, please explain to me in very simple terms why you think I don't need one, as I'm still very uncomfortable not getting one with the temps reaching that high. <The livestock you have are fairly resilient. The need for a chiller mainly stems from keeping very delicate corals in situations where the temp. fluctuates quite a bit throughout the day, usually due to the intense lighting. Even in a full blown reef tank the temp. can be run into the mid 80's (although not ideal), so long as this is consistent throughout the day.> I seek to keep them between 73 and 75 on the high side. Of course, now that I've had two pros tell me I don't need a chiller, I am once again second-guessing my potential purchase. <It will in no way be detrimental to your livestock, we both just feel it offers little if any benefit in regards to cost.> Also, reading more and more on reef tanks, I'm not sure I'm ready yet to get into that. Lighting prices, live rock prices, the tolerances that these species have, and the fact that I have no RO machine, no top-off machine, no sump, and the water here is not the best all tell me that I need to not do a salt-water tank. With the canister filter and everything I've purchased geared towards freshwater, these fish, with the money I'm spending on them, better live for a while. <!!> So, until I can get the first refugium set up and running and get some experience with better water quality and the like, I'm probably better off sticking with FW and the forgiveness that my current species gives with environment. Hopefully some fish and corals out there are breathing a sigh of relief right now!!! :) <In time 'do set your sights.!> As for the overflow boxes... Thank you for clarifying that I can use PVC. I saw I needed to use rigid plumbing, but was uncertain whether or not PVC would leach chemicals into the water and whether or not the cement used to bond joints was safe for the aquarium. <Hmm, glue, let cure for 24 hours and install.> I was planning on going with this one from e-Shops: http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18358 <The general design is a good one in regards the HOB boxes in general.> It is a dual-pipe overflow with 1.5" openings (I read the first Overflow FAQ and saw I needed more than one and that bigger can never be too much). <It does have dual tubes into the posterior of the box, but does sound like only one 1.5' bulkhead. This will limit the flow to an actual 750 gph or so.> Does one box with two overflows count as more than one in your suggestion? <In this case with two siphon tubes, yes. It is the siphon portion failing that is of concern. The bulkhead gravity drains and gravity has not yet let us down!> I also wanted to "Y" the two outputs of the box together into one pipe. Is this ok to do? <No, not on any overflow. The gravity flow depends on diameter/friction thereof. Combining two will cause them to flow as if they were just one.> The blockages normally form inside the box and not the pipes themselves, correct? <Here or there, blockages are not the concern. It is more an issue of air entering the siphon portion of the box, stopping the siphon.> My biggest question with the HOB as you call it, is how to control the amount of water flowing down. <By the pump input into the tank. The box will just remove water above a certain level, the pump will control how much and how fast above that level.> This box I'm looking at is rated for 1600GPH as per the FAQ saying bigger is better, and in a refugium, as well as through my chiller, need much lower flows from what I've read. I was looking to go about a six-times turnover rate for it, roughly 120 GPH for my 20H tank. That's over 10 times less than the HOB flows! <Redundancy is a good thing with overflows. This unit will only produce about 750 gph, you are still well under that.> How in the world do I keep my main tank from flowing into the refugium so fast? <Pump size/flow.> I understand that eventually the tank level drops, and the HOB stops flowing, but I want to prevent a mass flood of water to the refugium, a stop in flow, and then the refugium pump playing "catch up" just to have it start all over again. Waves of water inside a salt tank are good, but the last thing I want in my freshwater tank is a wave of water flowing down to the refugium every couple of minutes! It may start to sound like a leaking toilet and I don't want that! <All of the above is a common story with gravity fed overflows exceeding what they should run. Keep your flow to 750 or less and this will not be an issue.> However, the lowest HOB I can find is a single 300GPH device. Two of these still overflows the 120GPH by almost six times. Two of these is more expensive than the single-box dual outlet as well. <Yes, and if you are looking at the units I suspect, stick with the first box you have mentioned. A much better design.> So, I know I'm missing something. I looked all over your site pages about overflows and can't find a single item telling me how the return flow from the pump regulates the flow out of the main tank. See why I say I'm not ready for a salt-water yet? :) I know these are very basic questions, but most of the FAQs on subjects like refugiums and sumps are way more advanced than I am currently at, and the last thing I want to do is waste money and frantically e-mail you guys. I'd rather think this through first with lots of questions instead of getting a lecture later! :) <Hee, I understand, am currently in the same predicament re diving! The overflow will simply drain any water in your tank above a certain level. How fast water rises above this level is dependant on the size of the pump putting water into the tank, therefore how fast water is drained off.> Next, I'm trying to determine what to put in my refugium. I keep seeing deep sand beds as being one of the best options, but I'm fearful that since I read all of this on marine aquariums, that it would not work on my freshwater. <It does to an extent.> I'm not even sure how deep I should make it. 4"? 6"? Again most of these questions are answered for marine systems... but not really clear for FW systems that I found so I'd rather ask. <4-6' will be fine, generally deeper is better.> I do plan on putting plants inside of it, but I also want some place to finalize the nitrogen cycle. I'm tired of changing out water based on nitrate readings. I want to change out the water on a 25% to 33% as most people do instead of 50% or more per week because nitrates are too high. Yes, I know, different fish would have prevented that. Chalk another one up for inexperience before I found your web site. <A DSB will have a positive impact.> From what I'm gathering, I can remove the air pump and stones all together? <Yes.> Even if I use glass-tops on the main tank and the refugium? When you stated that I can provide the filtration inside the sump, don't you mean refugium? <Yes, I'm sorry, most of the people asking here use the terms interchangeably, I generally don't. Good that you see the distinction!> I am not going to be using a sump, per se. It will be refugium only. Sorry if that wasn't clear before. Now that it is, how would I get the mechanical filtration? <A filter sock if you wish to get rid of the canister.> That's also what my canister filter is for. Will I have to keep it for that? <You don't have to, but continuing its use is a good option, you do already have it.> Currently it provides all three filtrations, as it should since I have no other device in the tank for filtration of any kind. I was also going to eventually add a second XP4 canister to increase filtration inside the tank. Does this sound like a good idea or would that $200 be better spent elsewhere? <Hmm, elsewhere. A fairly complete SW setup can very often be had used for less than this!> Last, will I have to clean out the refugium as if it were a main tank? Gravel vac, etc.? <Same as marine, a bit of periodic stirring within the top inch or so to keep detritus out of the sand bed and into any mechanical filtration.> I'm trying to figure out how to do this if I have a DSB... moving this around is a big no-no as it oxygenates the bed which is the opposite I'm trying to do. <Yes.> Thank you, John <Welcome, you do have fair grasp of what it takes. Try and you will learn more than anyone can teach! Scott V.>
Re: Beginner Chiller Questions /Freshwater Refugium Qs 5/12/08 Scott, Thanks again for the help. <Very welcome.> The dual box I mentioned does have two drain pipes at 1.5" a piece. When you say single-bulkhead, what do you mean? <The actual gravity fed portion that gets plumbed into the refugium, separate from the two siphon tubes that come over the tank. Honestly it sounds like one 1.5' bulkhead from Dr. Fosters & Smith, but the manufacturer site is unclear.> I'm not familiar with the terms yet. The single ones I spoke of were at the same website, same manufacturer, but just single drains. <Yes.> If you fear air entering the siphon, does this mean that I should get two of the lower flow 900 GPH that are still dual-outlets? <This would be better, giving you four siphon tubes for redundancy. I must be clear (and somewhat biased), I do personally advocate against HOB overflows and for drilling your, or any, tank.> Would this be a better option? How else should I keep the siphon going? <Maintenance and vigilance to keep the siphons unobstructed and free of air accumulation.> What would cause air to enter the siphon? <Air bubbles in the water getting sucked in, settling and accumulating in the top of the siphon tubes.> The box I was looking at has a pre-box on it that is supposed to prevent air from entering the siphon tubes. Do these not work that well? <The foam is on the gravity fed lines, I would remove these from the box altogether. Too much restriction of flow on the tubes, siphon or gravity fed.> The only thing I meant by joining the outflows together was that I would "Y" them into a larger pipe. I suppose I don't know how large it should be, but I definitely would not restrict flow by using the same diameter pipe. I was thinking 2" or 3" pipe should be ok, but that is getting rather large. <For dual 1.5' pipes a 3' will be needed.> With one box that has two outlets, I can run both fairly easily. With two boxes that have dual outlets, it might become challenging. <Yes, trust me, if you are at all comfortable with DIY, do reconsider drilling.> If I did this route, I may get a 3" horizontal pipe and pipe the four outlets straight down into that pipe, and let that pipe be the inflow for the tank. Does this sound ok or is combining the flows like this still a bad idea? <Into one 3' pipe it will be fine.> I may be thinking too much like sewer piping and not enough like flow piping on this point. <In this application it works much like a sewer pipe, gravity fed, no pressure.> Also, with regards to the filtering... my refugium is going to be low flow, so I still need turnover in my tank, correct? I have roughly 450GPH max rated flow in my XP4 (I'm sure it's less due to filter material, probably around half?) currently, and my 120GPH through the refugium is definitely going to be too low for the main tank if I need at least 6 times flow. Am I correct on this? <More flow will not hurt.> If so, I might need to pick up another XP4 then, right? <Or simply add a $15 powerhead.> As for the filter sock, that will probably be something I get to prevent any of the main tank's detritus from flowing into the refugium. I'll look around for some, but if you have any suggestions I'm open. <Most the filter socks are fairly standard sizes with brackets that hang on the side of the refugium. Most Etailers good LFS will have this.> I'd like something that filters pretty small materials as goldfish waste can be messy yet incredibly hard to get filtered out mechanically. I just recently went with double the filtration that the XP4 comes with by filling two whole baskets with sponge material made for the filter. <Goldfish are messy.> When you state that I need to stir up the bed to get the detritus into the mechanical filtration, I got confused. Do you mean that this stirred up material will enter the return pump to go back to my canister filter or the filter sock? <Yes.> Because I had not planned on using any kind of mechanical filtration in the actual refugium. Just wanted to make sure I was on the same page. <We are.> What kind of sand for the DSB do you recommend? I want a relatively neutral composition as I don't need to change PH at all (mine hovers around 8.0-8.5). I also don't want to buy something that is specialized for marine aquariums and pay the premium for that if I don't have to. I do kind of like the black Seachem Fluorite material, or even the miracle mud for the plants, but wasn't sure if that was a good choice. <You will want a smaller grain than the fluorite for NNR. Possibly even consider a bottom layer of sand with an upper layer of fluorite with the two separated by some screen/thin Dacron felt material.> A pure white sand like the beach would also look good in the tank, but I'm not sure what type I'm looking for. I also didn't see any FAQs on specific material, but if I somehow missed them I'd be glad to take a look if you would point me in the right direction. <The idea of a FW refugium is not too widespread, but the same general principles that apply to marine refugiums will work here too.> I'm hoping that a twin-tube 24" is going to be well enough for the algae and the Anacharis I have in the tank. Right now they are both growing exceptionally well in my main tank, so I think this amount of lighting should be plenty for these. I was just hoping to avoid a costlier and hotter solution if I can go with regular 8000K fluorescents. <Look for a 6500K or so bulb for these, you will get better growth.> Currently I have a single-tube light on the 20H tank and it was growing algae pretty fast, so that's why I'm basing my decision on the fact that double power should be enough. They would be two 18" 15W tubes. <Considering the close proximity the plants will have to the light this will work fine.> Lastly, your point on the chiller is well taken. It brings up one last question for me though. You stated, and I've read, that stable conditions are far better than trying to reach ideal conditions with rapid swings. <Yes, within reason. Stable at 110 deg may be a problem!> With my species of fish, are they resilient enough to handle swings? <To an extent, more so than many others.> If so, how much is too much would you say based on your experience? <A few to half dozen deg at most in this situation.> I ask because I do notice that my temps can and do fluctuate anywhere from 3-5 C a day just with ambient temps around 72F. So it's rather large, and that too was concerning me and weighed in on my quest for a chiller. Does this change your prognosis at all? <Not really, not for these fish.> If not, I may actually reconsider the chiller as it's a lot of money. But I'll get it if I might need it. I'm getting more and more excited about this refugium. I was at first really hesitant because I thought it was way out of my league. Now that I know a DSB can help me out, and that I know a little bit more about what I'm doing, I can't wait to get it purchased and running on the tank. John <You may be surprised to find much extra temperature stability with the extra volume/surface area with the addition of the refugium. Have fun setting up! Scott V.>
Re: Beginner Chiller/Refugium Questions 5/13/08 Thanks again, Scott! Your answers were very helpful! <You're welcome, happy to assist.> When you stated, "I must be clear (and somewhat biased), I do personally advocate against HOB overflows and for drilling your, or any, tank," did you mean that you do advocate drilling? <Yes, very much so. I must say I have a 50% share in a company doing this. The company was started due to my passion for drilling for overflows, not passion because of the company! I will also point out to you there is nothing wrong with HOB overflows, drilling is just a far superior option (IMO)> If so, how long would a pro shop take? <A day maybe, possibly by appointment to get a fast turnaround. If they want your tank longer look elsewhere. The drilling process itself only takes five minutes. It is also easy enough to do it yourself.> I ask because I have only my one 75 gallon tank that my fish are currently tenants of and it would be pretty rough on them going back to the 20H tank for extended periods. <This is one point towards the HOB overflows, you do not have to tear down your system to use them.> I also have no tools for drilling holes in glass at the moment (I just started off on my own) so I'd have to see how much those would cost. Last thing I need to do is mess it up! :) <All you need is a drill (a cheap one will do) and a diamond coated hole saw. You can very well have both for under $40, depending on what deal you find on drills. Heck you can even rent one at many hardware centers!> If you do like it, you like the drilling because it's a cleaner solution and less prone to failure I assume, right? <Yes to both.> Trying to determine which route to take. Also, from Drs. Foster and Smith the picture shows the two drains on the single 1600 GPH (rated on their site) in the picture. I'll make sure of this before I order. <Yes, do. This will make a huge difference in flow.> I may also just get the two dual-outlet 900GPH and be done with it. We'll see. Again, thank you for your help! John <Welcome, a FYI link for you regarding glass drilling. Consider all your options and what suits you best. No one method works for everyone! Scott V.> http://www.youtube.com/watch?v=zwc3o_rGmLg
Re: Beginner Chiller/Refugium Questions 5/14/08 Scott, <John!> Got your link. If I wasn't so worried about my luck and having a cracked aquarium, I might actually try to do it myself. I'd like to do it, but I'm still fearful. The last project I did myself didn't turn out so well!!! <That is why I sent you the link. If you are not at all comfortable doing this, by all means don't!> I wouldn't even know where to start. I think for now I'm sticking with the single box, dual outlet 1600 GPH 1.5" bulkheads. Does that sound alright to you? <Yes, plenty.> The other option was the continuous overflow siphon dual bulkheads that don't use any siphon tubes, but those are almost twice the cost. If they are worth it, though, I'll get it. I want to get this right the first time with what I got. Been looking around for some substrate, and see that I want a very fine sand product. <Depends, you will not want too fine a substrate in the upper layers if you plan on rooted plants in this FW refugium.> First, I can't even find any so I must not know what I'm looking for. Second, I'm worried this will rapidly increase my PH level. <It can, you do not want aragonite for your application. A silica play sand is likely your choice here.> Do I need to counter this, and how high should I expect it to go? I already have pretty hard water here (lots of dissolved calcium), and the PH out of the tap is 7.2 and the PH in my tank is currently around 6.8. <Don't use a marine, aragonite, sand.> Just want to make sure I don't have to worry about this on a constant basis with chemicals. I planned on going with a 6-8" DSB for Nitrate reduction, with plants to help and release oxygen. <Sounds fine.> This won't leave a whole lot of space in the 20H tank for water. What do you think? Worth it? Comments? Suggestions? Thanks, John <Welcome, Scott V.>
Re: Beginner Chiller/Refugium Questions 5/15/08 Scott, <John.> One last question about the substrate: Is aragonite the same as crushed coral or marine sand? What about Oolitic sand? <All of the above are generally aragonite. Some 'marine sands' will say somewhere on the bag that they are safe for freshwater use, in which case they are usually silica.> I've been looking into getting some sand that is good for play grounds, but I've been seeing posts that some contain toxic materials even for humans, so I'd prefer to purchase from a reputable pet store instead of relying on the local home improvement stores unless you specifically ok that. <There is never a 100% guarantee what you are going to get. Buying at an LFS is not a bad idea.> Also, I think I'm going to reuse some previous substrate I had for my goldfish for the upper layers (around 1-2" thick) and then a 6" or so DSB with the finer material. This should help when cleaning the tank as I can carefully gravel vac or stir the upper substrate while leaving the DSB alone. <Yes, do consider some of the materials we discuss before regarding separating the layers and keeping them that way.> Thank you for all of your help. John Lindsay <Welcome, have fun, Scott V.>
Re: Beginner Chiller/Refugium Questions 5/21/08 Scott, <Hello John!> If I don't use any top substrate and just plant the plants direct, do you see any problem with this with your experience? <No.> I read the substrate faq you sent me (not sure how I missed this in my search) and I was reading that most plants grow in anything, but there are optimum substrates for different needs. <Yes, there are!> I was going to go with Black Tahiti Island Sand (FW or SW use, fine) which is black in color, around 5-6". <Although I do like the look/idea of this sand, it is silica. This can be used, maybe consider SeaChem's Black Sand Fluorite also. This would be my choice for this application.> I was thinking at first I wanted the white sand, but I think eventually the white sand will go dark the more I use it, so might as well start out with it that color. <Agreed.> Plus it will help to absorb light in the reversed cycle I'm going to use leaving less to bleed out into the surrounding dark environment (the refugium does not fit under my stand so it will be next to the stand). <A big factor.> Also, with a filter sock; how in the world do I mount this? I was thinking I could get a PVC union and a draw-string sock and mount the union on the end of the inflow pipe to the refugium instead of having to purchase a (inferior for my needs) 1" mount. Will this work or will the sock be under much more pressure than I realize? <This will work, I am developing a similar product right now.> I don't want it falling off or anything, but the retail mounts just don't seem to hold up to what I want or need. Also, will I need to isolate my pump in some kind of box to prevent it from ingesting all sorts of this sand? <You will want to assure sand does not get into the pump, yes.> I was looking to either place it directly on the substrate, on a square of acrylic, or in an actual acrylic chamber to help prevent it from sucking up the sand. <The latter would be the best, with baffles. Something as simple as a cheap Gladware bowl can work for this.> I really do appreciate all of your help on this. <Happy to be of assistance.> I'm getting closer and closer, and am looking to put in an order here soon and then I will report back once I get it installed and running! <Please do!> John <Have fun, Scott V.>
Re: Beginner Chiller/Refugium Questions 5/21/08 Hello, <Hello again John.> I'm setting up a refugium for my FW 75 gallon tank; I have written in on that topic separately with Scott's help. I will have a 6? DSB and a HOB overflow dual-bulkhead 1.5?. I plan on using some kind of PVC piping to input into the refugium. The bends will be 45 degrees instead of 90 degrees as explained in the refugium plumbing faqs. <A good idea.> I will be using an Eheim 1260 pump for return (I have a lot of head pressure to overcome, otherwise I'd use a 1250) and it will be passing through a chiller (which requires 480 GPH min). <A good choice in pump. Consider adding a ball valve to the output to throttle the pump back if you feel you have too much flow.> I was curious if I needed to hard-plumb the output of the pump and chiller back to the tank? <No, personal choice.> If it is best to hard-plumb, should I use the same diameter as the pump and chiller, or go larger? <The same size is fine.> I ask because it seems unnecessary to increase size just to decrease size back to the output fixture. <Agreed.> The output on the pump is Â¾?, the chiller accepts close to this size, and the return U-pipes are also Â¾?. <3/4' is a good size for this flow.> Thank you, John <Welcome, Scott V.>

Freshwater refugium, co2 questions 12/07/2007 hello; <Hello.> I own a 125 gallon freshwater aquarium with 12 Corys, 2 bushy Plecos, 8 upside-down cats, 2 pictus cats, 4 paradise gouramis, 4 African butterfly fish, and 15 tiger barbs. the tank is heavily planted with java ferns, swords, water sprite and moneywort. there are 2 36" compact fluorescent lights on top. I made a 20 gallon wet/dry filter and connected it under the tank with a hob spillover box. the whole thing has been set up for 3 years now and I have had no problems to speak of. <OK.> I am now thinking of turning my tank into a discus tank, as well as adding co2. I have been doing a lot of research on-line, but I still have a few questions. a friend of mine has a cool refugium he made and filled with a milfoil of some type. I was thinking this would be a good step to take before getting the discus (I plan on first removing the barbs, gouramis and butterfly's to make room). <Butterflyfish actually work quite well with Discus, the two species completely ignoring each other. Your real problems will be with things like Synodontis and Pimelodus, which are a bit too active and nippy to really work well with Discus. Paradisefish (Macropodus opercularis) won't appreciate the super-hot water Discus like either.> eventually I want 12 discus. my plan was to simply raise my wet/dry up about a foot and place a 20 gallon plastic bin next to it and use a siphon or spill box to transfer water. then place my water pump in the plastic bin. is this a good idea? <In theory, yes. But do remember the more splashing and water circulation, the more quickly the CO2 will leave the water. High levels of CO2 are good for plants, but fish aren't crazy about them. In general, it's often better to focus on either plants or fish. If you look at the 'Nature Aquarium' type set-ups, fish play a very minor role, and the stocking level is very low. Discus are quite demanding fish, and your time is better spent focusing on water changes, water quality, etc. Discus don't like bright lights either, limiting your selection somewhat, unless you provide lots of shade from the very start.> then I want to use a small compact fluorescent over the refugium and set it to run at night. what are some good plants for a refugium? <Almost anything. Floating plants that grow fast and are easy to crop work best, and algae best of all.> do I have to add any substrate? <Nor for algae of floating plants.> I would prefer not to. I also want to add a co2 system. does it make more sense to add the co2 before I get the discus, or after? <I'd get it first, so that you learn how to keep a constant pH, which adding CO2 tends to work against. Once you have the perfect balance of pH with CO2 concentration, and your plants are all thriving, then get your discus.> all co2 systems I have seen come with a bubble counter and diffuser. are these things really necessary? <Yes.> my plan is to just use a cheap foam bubble wand and place it in the bottom of the bio chamber in my wet/dry. <Won't work. CO2 is largely insoluble in water, hence the need to maximise the time the CO2 is in contact with the water. That's what the bubble box thing does. It stops the CO2 from bubbling up to the surface too fast. You're also going to have real problems keeping a constant CO2 level if you do it by eye. Adding CO2 at random will do no good to your plants, since they respond only to steady changes in conditions, not sudden ones. Obviously adding too much CO2 will harm your fish by reducing the pH.> will that be harmful to the bacteria? <Filter bacteria don't like acidic water, so anything that reduces pH is bad for them. Once the pH gets to 6 or less, they stop working.> if so, were is the best place to add the co2? <Doesn't matter, so long as the CO2 level is constant.> will having a refugium light at night, and plants growing in the day allow me to run co2 24 hours? <You probably don't want to do this. A 12 hours on, 12 hours off system should work better. Most plants need a dark period, and don't thrive under constant illumination.> if so can I use a regulator without a solenoid. <No idea.> my water is moderately hard, will I need an RO filter, or will this setup be sufficient? <Depends on the fish being kept. But as a rule, moderately hard water with a neutral pH is fine for captive-bred Discus. Wild-caught Discus are a different matter. In any case, the KH and pH are critical factors in determining how much CO2 to add to the water, so you will need to measure those and act accordingly.> I really appreciate any advise you guys can give. <Cheers, Neale.>

Lighting and pump selection questions 12/1/07 Hey guys, you are great. Really appreciate the website and the time you take. <Hello Paul, thank you.> I've got a few questions in different areas that I couldn't find final answers to on WWM. I am setting up 120g (4x2x2) glass freshwater rainbow/Pleco tank. It will have some plants, but pretty easy stuff to deal with -- Anacharis, java moss, java fern, hornwort. I've been able grow these in other tanks without typical plant substrate (attaching to lace rock and Mopani), so expecting to be able to do the same with this tank, assuming I can get enough light down to them. It will have a black back. Substrate will be med brown. Lace rock and Mopani will be used liberally. <OK> First question is lighting. From what I can gather, watts from florescent strips (T12) to T5/T8/HO/VHO to power compact to metal halide are not created equal. I.e., you can't just compare wattage output. Some create more heat; some penetrate into water better; some are more efficient, etc. <Correct.> I've got 3 48" dual lamp T12 florescent housings with electronic ballasts from a garage tear down that are fairly new. I could easily put these inside a DIY canopy for a 240 watt set up. I've been experimenting with 'daylight' bulbs from local Home Depot that are rated at 6500K color temperature and have been pleasantly surprised. These bulbs for 40w T12 run about $5 each. <This could work assuming the bulbs have an adequate CRI and you take steps to waterproof the fixtures.> I can get a 4x65w (I think that is the wattage) power compact fixture locally for $150 or so. The price of power compact bulbs seems to be the most expensive per watt, though. <They can get pricey to replace bulbs.> Another option is to pick up a T5 or T8 set up. I've found one I like locally that is 4x54w T5 for about $180, bulbs included. The output is 216w or so, but the reflectors are much better than the T12 strips I have, so I would suspect the T5's are getting as much light to the tank, if not more (am I wrong on this?). I can also pick up a similar T8 set up for about the same money. <The T5's will have superior reflectors. These would be my choice, perhaps with one additional bulb. With these lights it is easy enough to add additional bulbs on individual reflectors should you want or need more light later. > Another option is to pick up two MH's. I can pick up some decent one's locally for about $140/each. I've also thought about putting a bunch of sockets with some compact fluorescents with 'daylight' bulbs. Would these be any good? <Possible, I would stick with the T5.> So what would you go with if this was your tank? I am concerned about power usage, replacement bulb cost, bulb life, ability to 'penetrate' to lower depths, heat from bulbs and ballasts, etc. Last, what is a pulse start ballast/bulb with metal halides? Does it matter what you get? <Probe start bulbs have an igniter to light the lamp built into the bulb, not the ballast. The pulse starts have just the opposite built in. The bulbs should be used with their respective ballasts.> Now onto pumps. I am running a sump. I am looking at pumps. I have two 2" drains in overflow boxes and a 1" return. The LFS I like best in town, who has never led me astray and has been 'right' about everything so far, carries Iwaki, Corallife (or is it CoralSea?) Gen-X and a few others. They readily admit they make more money on the Iwaki and Corallife, but say they like the Gen-X very, very much, and a number of the employees say they have them at home and stand by them 100%. Anyone know anything about these pumps? If price wasn't an option, if you were looking for 1000-1200 gph at 4.5' head, what pump would you buy? Why? If you needed to save a little cash (say, under $200), what pump would you buy? Why? <Sump style filtration is not optimal for planted tanks due to the outgassing of CO2, but they can work. Consider lowering your flow through the sump to a few tank turnovers an hour to help this. I would personally stick with an Iwaki here just for the reliability of the pumps. They just run a long time with little or no maintenance. If you choose to go with a lower flow rate, consider a quality submersible such as an Eheim.> Last, for drilling sump, should I drill hole on side wall as low as I can safely? Should I drill in bottom (I can elevate sump slightly and plumb from bottom, but these seems potentially a PITA that isn't worth it). Should I just plumb bulkhead to input to pump, or should I put some plumbing inside sump (like 90d elbow down off bulkhead to reach down into the sump further)? <The latter option will work fine.> Thanks for all the help. Paul <Welcome, good luck, Scott V.>

Re: Lighting and pump selection questions 12/5/07 What about ditching the trickle filter (via sump and bio balls or bio bale), and attaching fluidized bed to the sump. Considering price of bio balls, really isn't much of a jump to the fluidized bed. <You could, this could theoretically decrease your CO2 out gassing.> I also hear that because they agitate some much, the detritus accumulation will be almost nil, <Ideally with some sort of mechanical filtration first. You will end up with a layer of detritus in the fluidized bed, probably floating on top of the media. It would get accumulated by the bioballs anyhow. You will be able to siphon it off in the fluidized bed.> necessitating cleaning at a rate of *maybe* once a year. This definitely appeals to me (I am tired of cleaning canister and HOB filters). <Understood, me too. Good luck, Scott V.>

Freshwater sumps 11/28/2007 Hello again. You have been very helpful so far and I feel bad about pestering you for info but again there seems to be a lack of info on this subject. I am converting from marine to freshwater (most people go the other way) and have a sump which I want to use with this system. The tank is about 500ltrs with a 100 ltr sump. My question (to finally get to the point) is what would you recommend to put in the sump. Currently the first section is bio balls, then miracle mud with colerpera (sorry about the spelling) and finally live rock with a live sand bed. I know the live sand will 'die' and the live rock would be a waste. I was thinking about keeping the bio balls but replacing the mud with gravel and some sort of plants. The main section was to be changes to gravel. Have you any suggestions with what I am proposing. Any help gratefully received. Many thanks Paul. <Hello Paul. Unless you're keeping a hard water aquarium for, say, Tanganyikan cichlids then don't leave anything calcareous in the sump. For a standard community tank or similar, then opting for biological filter media of some type is probably the way forward. More bio-balls or some sponges would work well. Because nitrate control in freshwater systems is both easier (plants, water changes) than in marine tanks and less critical (freshwater fish largely nitrate-tolerant) there's no real need to provide denitrification in a freshwater tank. But some people have very effectively used 'vegetable filters' and 'algal scrubbers' as part of the filtration system, by placing fast-growing plants/algae into a brightly-illuminated chamber. There's a book called "Dynamic Aquaria" that discusses these, among other such esoteric topics. While hardly a book for the casual aquarist, it's an interesting read if your library has a copy. Basically the idea is that you optimise plant/algal growth, and then crop the plants (even daily!) effectively removing wastes in "solid form". Some freshwater plants, such as Cabomba and various floating plants, will grow incredibly rapidly if provided optimal conditions. I hope this helps, Neale.>

Stepping up to 90 gal with sump 10/28/07 Greetings Crew, <Hello, Scott V. here.> First of all I truly appreciate the wealth of knowledge available within your postings and website. I have enjoyed the hobby of keeping aquariums since 2001 when I began with a 20 gallon freshwater tank. For the last three years I have maintained a 55 gallon tall octagonal fresh water tank, currently with 3 parrot cichlids, 3 silver dollars, 4 tiger barbs, bristle nosed Pleco, and a Botia. I would like to set up a 90 gallon industry standard tank and for the first time, use a DIY sump filtration system. <Nice step up and the sump makes servicing much easier. > I am new to the sump system but am beginning to wrap my mind around the concept. <Excellent> I would like to use a 20 gallon long tank to be the sump with the equivalent of a 400 gph (at 4 feet rise to the tank) pump. Does this sound sufficient to prevent flooding? <Flooding would depend on your tank's transit volume, how much flows back into your sump due to water in your plumbing and siphon from your return.> I am unsure what to use for the best biological filtration. Are bioballs or a BioWheel best to purchase?? Is gravel a good choice if put in the refugium?? What is the best for a beginner? <I am a fan of BioWheels, but you could use the balls. If you want a planted refugium section, I'd take a look at the peat/African violet soil type mixes. You can read more on substrates at http://wetwebmedia.com/FWSubWebIndex/nicebottoms.htm. If you are not planting in the sump I would not include any substrate, to facilitate cleaning.> Ideally, I would like to build my own sump, but I know of an offer for a reasonably priced 6 month used commercial filter (http://www.carolinafishtalk.com/forum/viewtopic.php?p=22187#22187).? Allegedly this filter is for a 400 gallon aquarium.? Is it worth considering for my 90 gallon set up?? Seeing as it would fit in my cabinet, would it be too large of a filter for my 90 gallon tank?? Or is it advisable to create my own sump? <Would work, don't worry about over filtering. But, building your own can be an awful lot of fun and very satisfying, don't discount your ability to build one that will not only work fine, but will better suit your specific application and needs.> Finally, I am researching a MegaFlow 90 gallon tank.? I have heard good reports about the double paned overflow, but I believe the drilled holes are in the bottom of the tank.? Is it a bad idea to get a tank with drilled holes in the bottom of the tank?? Is there anything that could be done to improve on such a tank? Thank you kindly for any assistance or direction. I am in the learning and planning process. <At your flow rate the preinstalled overflow will be near its safe limit, but will work. Holes in the bottom of the tank allow you to get the tank close to wall (in some instances totally against the wall). The possible downside is a leak. Both the overflow and bulkhead would have to leak, but if they did that's a lot of water. It is rare, but can happen. There are two other options. First, a hang on back siphon overflow. They use a siphon created by a powerhead or pump vacuum to function. If the siphon is broken, water is on the floor. The other option is an overflow box or elbow near the top. This has the advantage of a gravity fed overflow and if a leak were to develop it doesn't involve all the tank's water. See http://www.momsfishsupply.com/photos.html for some ideas, but I think the MegaFlow is probably the best option for your application. Hope this helps, thank you Scott V.>

Freshwater deep sand bed experiments 7/2/07 Your website alludes to some experiments that were to be done about nitrate reduction using deep sand beds in a freshwater system. Any results available? <Mmm, w/o a "trip" to the/a large library here with access to computer bibliographic search... I can only state from vague memory (nothing in my hard files) that I have seen articles in other languages (German, French, and likely Italian and Japanese) re this phenomenon. There are discernible "effects", practical implications of DSBs, use in FW aquariums> There are a couple of problems I could see. The marine sand beds are dependent on sand sifters and burrowers it sounds like, <To a larger extent... the variability in the make up physically, chemically, biologically... of such disparate "habitats", marine, freshwater and otherwise is huge... Suffice it to state that many FW bodies have significant infaunal populations. I suggest perusing a limnology text...> to move material around and prevent excess stagnation and hydrogen sulfide production, according to some web site sources. Maybe no such organisms are available for freshwater systems. <Mmm, perhaps not yet... but like marine "live substrates" these can be made pretty easily...> Do the sand beds really work for freshwater? Particularly for a soft water (Amazon) tank.... <Mmmmm, interesting thoughts... IF one could receive a starter inoculum... or even just some "muck", what have you, from an importer of... plants from this region... Bob Fenner>

Is the adhesive on EPDM weather-stripping safe for Fw fish and plants? 10/24/06 Hello WWM Crew, <Danny> I am considering using the pressure-locking baffle system for building my 20 gal glass sump with acrylic partitions. I see an article on using EPDM weather-stripping for the baffles on your site. Have you heard of anyone else using this with success? <Mmm, no> Is the self-adhesive safe for the fish and plants in the tank? I am concerned about introducing any potentially toxic glue into the environment. <Me too> Thanks, Dan <The EPDM itself is quite safe... if there's a simple way to remove/trim off the adhesive... I would. Perhaps contacting the manufacturer will get us some useful information. Bob Fenner>

Freshwater Refugium Substrate - 08/05/06 Dear WWM Crew, <Michael> I'm just looking for some advice on an appropriate substrate mix for a freshwater refugium. <There are a few possibilities... depending on what you want to "do" there... what the make up of the rest of the system is, your water...> The system is a 150 gallon acrylic set up as a semi-aggressive community with large fish. Filtration is remote in a separate filter room and is basically made up of a large wet/dry and a large canister filter on a closed loop. Upon taking over this account and running initial testing I was not surprised to find excessive levels of NO3 and PO4, not to mention the pH being quite low. My first suggestion to the client was to change the tank over to a planted community, but we then decided to go with a 25 gallon refugium as he had grown attached to his current stock. My question is, what would you recommend as a good mix of substrate to run in this refugium that would be good as a plant base and to build a good anaerobic zone for NNR? Would an inch base of oolitic aragonite covered with 3 inches of Seachem's onyx plant substrate be a reasonable mix? My thought on this is that the aragonite would provide for a good anaerobic layer and at the same time provide a little extra buffer for the water of this heavily stocked system plus some added KH for the plants in the refugium. Any thoughts or recommendations would be greatly appreciated. Thank you for your time. M.P. Gillespie. <Mmm, if it were me/mine, I might try any one of a few types, sizes/grades of various media. My first trial/go I'd use a medium (#2, nominal 1/8" diameter) "natural" gravel of four-five inches depth. Bob Fenner>

Freshwater Refugium - 2/28/2006 Hello WWM Crew, I was curious to see if you could guide me in the right direction as far as setting up a freshwater refugium. I have an AES catalogue with a section containing a number of freshwater invertebrates such as copepods, daphnia, blackworms, etc. Would these critters have the same potential for reproduction and feed benefits as the organisms in my salt refugiums? <Yes> Would these critters also help to maintain a soft substrate within the refugium and if so would this substrate provide NNR as does a DSB in a salt refugium? <To a large extent, yes> Thank you in advance for your advice. Myk. <I would substitute embryophytes/vascular plants for algae/thallophytic life used in marine refugiums, but otherwise mimic the technology utilized in saltwater settings. Please read here: http://wetwebmedia.com/marsetupindex2.htm see a few lines down, the linked files having to do with refugiums? This and a Google search on WWM re "freshwater refugiums" (looked at the cached version), will show what we have on the subject. Please write back re your experiences/adventure. Bob Fenner>