# DIY Freshwater Sump/Refugium combo questions



## 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 over-complicating things?


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## clep.berry

A canister plus a sump sounds like overkill to me. Essentially, one sump/pump should be able to do the entire job imo.
I thought the idea of a refugium for that tank would be mostly for wq control and heavy plant growth to absorb ammonia/trites/trates - the free food sounds nice though.
You're basically building a mechanical/biological filter in the 1st chamber with the plants being a further filtration device.
1 gallon of filtration media should be more than enough for this tank with your refugium able to use the rest of the water volume for evaporation/plant growth purposes.
cb


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## luananeko

Refugiums are both for water quality control as well as a safe haven for growing live food like shrimp and snails. But the idea of having this big planted section of water sitting under the main tank with critters in it that you don't see unless doing maintenance seems like a bit of a waste... Obviously you would lose a little in efficiency by putting things other than shrimp/snails in there, but if the sump is big enough then it seems like losing a little bit of efficiency in return for aesthetics is doable. The more I research the more it sounds like the canister would just be overkill unless I stocked the refugium too much that it's a net drain on water quality rather than a net gain.


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## clep.berry

About that idea.
If you oversize the output pump, take a branch and valve off the T, you can effectively use the same media to filter the main tank water as well as the post-refugium water.
Overflow > filter > Fuge> pump > Main tank + Loopback into filter

If you get the aesthetics right, you wouldn't need the sump below the tank - you could have it beside it!
You'd lost the auto-top up ability of the sump though.
cb


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