Freshwater Sump/Refugium combo for 400+ gallon tank?

[Luananeko]

I've been doing a bunch of research for a 400+ gallon cichlid tank I'd like to set up once my husband and I move into a bigger place. Since the tank would have an oscar and a group of geophagus, it sounds like live plants would be pretty futile. I've heard about folks using a sump/refugium combo for filtering larger tanks while still letting them keep plants and grow snails/shrimp for live food for the main tank. The idea sounds cool and like it would be easy to put together a DIY solution for it, but I had some questions...

1) I'm reading that sumps should be around 25% of the main tank size... Would a custom stand be able to handle the weight of both the main tank and the sump underneath it (400+ gallons for the main tank, 100+ gallons for sump)? Or would it need to go off to the side to distribute weight?

2) Is there any reason you couldn't turn the refugium section of the sump into another tank on display? Seems a waste to have a planted portion of the tank with critters you can't see unless doing maintenance...

3) If you turned the refugium into another display tank, would you be able to keep more than just snails/shrimp/plants in it? Obviously it would have to be lightly stocked to avoid negating the benefit of the plants... Maybe half normal stocking, or would it have to be even less?

4) Would the sump alone be enough filtration if the refugium was partially stocked, or would it be a good idea to add in a canister filter too?

I'm thinking the final set up would look something like... Tank drains into sump with mechanical filtration & biotubes, then drains into the refugium, then drains into section with return pump, which pipes into the intake of the canister filter, which then pumps the output back into the main tank... That way the water from the main tank gets filtered before going into the refugium, and then it's filtered again before going back into the main tank. Would this work, or am I overcomplicating things?

 

[Terrance]

If built properly, your stand would be able to withstand the weight of both tanks. I'd be more concerned about the floor. Can your floor support a couple thousand pounds?

If your goal is to see plants and animals, then you shouldn't keep them inside the sump. Put all of them inside another display tank. IMO its not a waste at all to keep plants in a sump.

You would need a strong pump to push at least 4000 per hour (you have messy fish). Adding canisters would create more work for you. Water drain into a mechanical filter (filter pad or sock) and media for biological filtration. Then flow into the refugium for the plants to help improve water quality. Then the water flows into the pump and goes back to the display tank. Very easy and simple. If you want less flow through the sump, then the overall gph will be reduced and you will have to get some powerheads to generate enough flow throughout the whole display tank.

Most important thing you will have to do for your system is the weekly water change. It will save you more money than using electricity for your tank.

 

[Luananeko]

Good point about the floor... I'll make sure to check that when we finally get the new place

The reason it seems like a waste to not turn the refugium portion of the sump into another tank on display is because turning a big 100+ gallon tank totally into a filter seems like such a missed opportunity to still make it look nice... Sure, it may not be 100% as efficient, but it seems like there could be a balance between functionality and aesthetics.

The canister filter idea is mostly in case the sump alone wasn't enough filtration on it's own. If folks think the sump is enough I have no problem leaving that out of the final plan. Still is an option as a suplement if I can't find a pump strong enough to get the turnover I need out of the sump. Weekly water changes would still happen regardless of what the final set up looks like.

 

[Terrance]

100g is pretty expensive. There is no general rule for sump size. The bigger, the better. If for whatever reason you can't get a big tank, then just get a 55g when the dollar per gallon sale comes.

On many occasion, I also tried making my sump look good, but it never does. There just too many wires and equipment making it look messy.

 

[Luananeko]

Well, the tank is still a ways off, so for now I'll stick to planning on the 100g and adjust once I know actual finances at the time.

I think if I make the stand to have an opening that just shows the refugium portion of the sump it should be pretty easy to hide the wires... Inlet/return pipes would be in the sections behind the closed area, same goes for the heater. What other wires or equipment would there be?

I put together a rough diagram of the design I'd be aiming for, it's not to scale at all but gives a general idea of the layout. See any problems? I'm thinking the opening in the stand would go from the divider between the refugium and bio stars to the divider between the heater and refugium.

 

[Terrance]

Looks really good. The hard part now is determining the flow through the fuge for plants to survive, but enough flow to circulate the display tank. Many plants like slow flow. And you won't be able to use Co2 effective. Lots of stuff to think about.

 

[Luananeko]

Yep, wasn't planning on CO2 I'm thinking lots of floating plants, and medium/low light plants for the rest, hopefully ones more tolerant of faster currents. Anubias with driftwood maybe? Though I hear refugiums are supposed to have faster growing plants...

 

[Terrance]

Water lettuce is my favorite. Its used often in ponds with messy kois and goldfish. Some reports say they block so much light and suck up so much waste from the water, that anything below the the lettuce will die. I'm not even sure if the legendary java moss could survive with water lettuce.

Watch the mesh/polyfill between the fuge and return pump. Its the spot that will clog really easily from plant debris.

 

[Luananeko]

Yeah, the mesh/polyfil section is the only part I'm not sure if there's a better way to do... I know water needs to enter high, exit low in each section, but if there's shrimp/fish/snails then they'll get sucked into the return pipe unless theres some netting in the way... I guess I could go with a more open mesh and accept that some snails/baby shrimp will get sucked up.

The water lettuce is a good idea, I haven't tried that one yet I think most of the more light needy plants would end up on the side furthest from the return pipe since the water lettuce should tend to gather on the side the water exits that chamber, leaving more light getting through on the other side. I guess I could harvest some of the lettuce when it gets too thick too to help keep it from being too dark on that side...

 

[Mark388]

I did this just on a smaller scale with my 100g cichlids tank and a 20g sump. It moves around 600 gph.

It's been set up or about a month now and the biggest draw back is the difficulty to clean my sump. Mine is real make shift and will be improved later in the summer but it has three sections. 1/3 with filter media made of filter padding I got offline 1/3 middle that will house plants and 1/3 return for my pump.

I'm not sure how plants will do in the sump as there is little to no C02 getting to it IMO. After it flows from the overflow down the pipes taking 4 90degree turns just to get to the sump.

As for you tank I think it would be a good idea to black out the filter media section of the sump and return if you were to make it a show tank. It wouldn't be difficult to hide the wires and make it look nice.


FYI the biggest problem is that your media will get filthy fast. Just like a HOB filter if you don't clean the media often, just on a much larger scale.

 

[Luananeko]

The sump wouldn't be air tight, so I'd imagine the CO2 would come from normal gas exchange. I'm not planning on doing any CO2 injection, so the refugium would be a low-tech section. I could even tweak the design to be a wet/dry filter where the water trickles down over the bio media before entering the refugium if CO2 is a concern.

From what I've read, adding that egg crate to leave an opening below the bio-media and then having a hole drilled for sucking out debris, combined with keeping the bio media in bags for easy removal helps make the cleaning process much easier Depending on the sump design some folks have gone 2-3 months between needing to clean their sumps, but I don't expect to be able to go as long since I'd have the refugium debris to clear out of the baffle to the return area. I'm thinking it might make more sense to swap the baffle to being a solid wall with holes drilled through and have one wall of mesh on the other side. I think it should be less clog-prone that way.

 

[Andrew McFadden]

This is how mine is setup and it work great. Better than anything imo

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[Luananeko]

Wow, way different than other designs I've seen! So you have your plants in the same area as the return pump? Do you have any issues with plants getting into the pump?

 

[Andrew McFadden]

Wow, way different than other designs I've seen! So you have your plants in the same area as the return pump? Do you have any issues with plants getting into the pump?

No I siliconed p.glass if you can see it on both sides. The water goes down from an overflow into a trickle filter ( that I had from a small salt tank) then I drilled a hole and ran pvc down to the bottom of the tank (29 gallon tall). Then siliconed the p.glass filled that part full of small rocks and sand. Then it flows up and out of there into the planted section then flowed over the next piece of p.glass into the return pump area. It's not a lot different then the pic you or someone posted above.

 

[Luananeko]

Ahhh gotcha, just couldn't make out all the areas properly from the pictures! Very nifty I can see why once folks try wet/dry or sump filters they don't go back. The amount of filtration you can get out of them looks impressive and you don't have all your equipment in the tank!

 

[Andrew McFadden]

The only thing is when picking out what size tank (refugium) if using an over flow vs a drilled tank you want to make sure its big enough to hold all the water that's going to come down if the power goes out. The way to go is drilled imo but I have always been to scared to drill it lol so I use the overflow boxs.

 

[Andrew McFadden]

Ahhh gotcha, just couldn't make out all the areas properly from the pictures! Very nifty I can see why once folks try wet/dry or sump filters they don't go back. The amount of filtration you can get out of them looks impressive and you don't have all your equipment in the tank!

Oh and that's not an actual aquarium pump its a sump from a hardware store. They are cheaper and youll get more gph out of them. On my return line I have a ball valve to adjust the flow (gph) and a check valve

 

[Andrew McFadden]

Ahhh gotcha, just couldn't make out all the areas properly from the pictures! Very nifty I can see why once folks try wet/dry or sump filters they don't go back. The amount of filtration you can get out of them looks impressive and you don't have all your equipment in the tank!

I still use a canister aswell. But that's due to my electric bill and worried when I'm not home that my siphon may break. Witch is another reason why a drilled tank is better.So I don't run it except for when I'm home. But ill tell ya when its just the canister running and my water starts to look dirty (not so clear) due to it needs cleaned. I'll turn that sump on and in 5-10 min. It's clear lol its great

 

[Luananeko]

The only thing is when picking out what size tank (refugium) if using an over flow vs a drilled tank you want to make sure its big enough to hold all the water that's going to come down if the power goes out. The way to go is drilled imo but I have always been to scared to drill it lol so I use the overflow boxs.

Yeah, there's no way I'd feel brave enough to drill it myself either, lol. I'd be going with a 4000 or so gph pond pump for my return pump due to how messy my stocking list is combined with the tank volume and expected gph loss due to gravity. I've found some interesting ideas in my research for how to make an overflow that maintains the siphon without dumping large amounts of water into your sump when the power goes out:

Or a little more ungainly...

Both of these should limit the amount of water the sump takes on to just being a few inches of water plus the volume of the piping.

 

[Andrew McFadden]

Yeah, there's no way I'd feel brave enough to drill it myself either, lol. I'd be going with a 4000 or so gph pond pump for my return pump due to how messy my stocking list is combined with the tank volume and expected gph loss due to gravity. I've found some interesting ideas in my research for how to make an overflow that maintains the siphon without dumping large amounts of water into your sump when the power goes out:

Or a little more ungainly...

Both of these should limit the amount of water the sump takes on to just being a few inches of water plus the volume of the piping.

Right its the same with mine, but you'll still get some. Once the water level drops below the overflow box the water stops. The bigger the tank (witch has more surface area) the more water is going to come down. Believe me I know I've ran a few over before lol so you'll need something big enough that can still hold all that water plus whatever might come down. Make sure if you make a overflow box its big enough aswell the more water you push to the tank the more the box has got to get down. I screwed up there and had to put on another.

I compared the pond pumps to sump pumps and they was still cheaper and gave a lot more gph. Just a heads up

You sound like you have done a ton of research or have had them before. So ill stop giving you things to keep on/in mind, don't want to make ya mad.
Just thought you would like to see how I did it.