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What to do with a plugged overflow?

Freakgecko

CCA Members
So earlier this year I purchased a 180 acrylic with a drilled corner overflow. It has minimal access holes across the top panel of acrylic, and they are all currently filled with the intake/out of my canisters, as well as cords for heaters and a strong power head.

I plugged the overflow with a bulkhead and some pvc pipe glued to the bulkhead. I was originally running one of the intakes for a canister filter to keep it from becoming a dead zone, however, I don’t have the sized canisters I would prefer and therefore needed to move the intake back into the main part of the tank to help filter debris in the water column.

So the question: what should I do to ensure that this doesn’t become a toxic zone for the tank? Is it going to become one at all?
 

Wobblebonk

CCA Members
So you could put a pump (or airline I guess) at the bottom back into the main tank and put filter floss or foam and make a matten filter style thing that looks like an overflow :/ or buy a cheap 40 or 75g and make a sump...
 

Wobblebonk

CCA Members
To be honest I also think you should put a sump on it... or you could plumb it directy to a canister filter, but uhhh I'm not sure I would ever really do that.
 

Becca

CCA Members
Staff member
To be honest I also think you should put a sump on it... or you could plumb it directy to a canister filter, but uhhh I'm not sure I would ever really do that.
Our 210 is plumbed directly to canisters but the intake and outflow are both outside of the overflows because the filters brought water in faster than the overflows could handle.
 

JLW

CCA Members
Plumbing through the bulkheads on an overflow solves one of the major risks of a canister filter. With a traditional set-up, should the tubes come off the canister filter, or just leak, they can basically drain the entire tank. If its your up-high output, you'll drain 5-6" of water, but if its your down low intake, you're looking at an entire tank on the floor.

If you plumb through a corner overflow box with overflows, you have basically three options, all of which mitigate risk. First, you can plumb both the input and output through the holes, and attach a tube on the output to dump water into the tank (so you're not just filtering your overflow box! :). With an airbreak in the line, you'll only siphon either the overflow box (if the intake pops) or the volume to your airbreak.

Second, you can plumb just the input through the overflow box, plug the other hole, and have your output elsewhere. This doesn't really offer any advantages over the above.

With either of these options, you'll have to keep the tank reasonably full, or the filter won't be able to pull in water. Evaporation can be a pain.

The best way to do it, in my experience, is to plumb the output of the canister into the overflow box, plugging one hole. Put the input somewhere else. The overflow box turns into an aeration chamber. This does not minimise any risks, however.

Note that putting an airbreak in the input doesn't really help -- if its close to the surface, you'll pull air in, potentially breaking your canister filter's siphon. And, if its too low, you'll have a lot of water on the floor before it even hits it anyhow (though, it might make the difference between 50-gallons and 80-gallons on the floor!)
 

Freakgecko

CCA Members
The reasons for no sump is 1.) cost, and 2.) the stand does not open up well for a sump to be placed inside. A 20 long was hard enough to fit underneath (grow out tank). I may end up plumbing to the canister, but I’d rather have it plumbed to an fx5/6 rather than the 405 I currently have on it. Not always easy to convince the wife to spend more money on fish lol
 

CSnyder00

Bearded Wonder
Staff member
If you are simply concerned about a dead area in that overflow, just run an air tube down to a foam cube filter. That will draw water in and out and add a tiny bit more biofiltration. Swiss Tropicals sells full sheet and whole cube filters and tubes that wouldn’t cost you that much. If you have a lifter, I think I actually have some poret foam laying around you could cut a piece from for a small fee...
 

Freakgecko

CCA Members
If you are simply concerned about a dead area in that overflow, just run an air tube down to a foam cube filter. That will draw water in and out and add a tiny bit more biofiltration. Swiss Tropicals sells full sheet and whole cube filters and tubes that wouldn’t cost you that much. If you have a lifter, I think I actually have some poret foam laying around you could cut a piece from for a small fee...
I actually do have an aqualifter, and should have something laying around. Thanks for the idea, that’s perfect! Never even thought about the lifter
 
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