[ElleDee]

I'm trying to figure out the plumbing for a sump and I haven't seen examples where people use a typical overflow with a lily pipe on the return. Is there a reason for this? ADA indicates a 17 mm lily pipe with enough GPH is good for a 120P, so it shouldn't matter if this is done with a sump or canister, right? Is there some other consideration I'm missing?

 

[Leeatl]

Only thing I can see is with a sump you want to have good flow and turnover of the water . A Lilly pipe may not be able to handle strong flow without splashing , shooting water up , etc . I use DIY spray bars and 2 DC pumps rated at 845 GPH . I have them set to %80 to get it balanced .

 

[ElleDee]

Only thing I can see is with a sump you want to have good flow and turnover of the water .

Isn't that also true if you're running a canister? Do people running canisters just accept lower flow rates than people running sumps? I've never run a canister, so I don't know the considerations.

I went back and looked at the ADA website and they actually recommend 13 mm tubing for a return for their 120P and a flow rate of 158 to 316 GPH. The 17mm tubing is recommended for their 180cm tank at 316 to 475 GPH, and I could probably use that if I wanted to, but I reckon that's a lot less flow than you're pulling? (And no, I don't plant to use official ADA lily pipes, but I was thinking that their calculations and recommendations would be sensible.)

 

[Leeatl]

You are right on the canisters , but I don't think they push as much water as a sump return pump . Best I can say is try it and let us know how it goes .

 

[minorhero]

If you have a sump then you already drilled your tank. Not much reason not to drill your tank for return and less maintenance (admittedly if using stainless steel lily pipe maintenance is pretty minimal. But there is nothing wrong with using a lily pipe. Lots of styles so you can pick one appropriate for the type of flow you want.

Personally I wouldn't trust anyone who makes filters to tell me how much flow to have in a tank. I want at least 4 times actual turn over an hour.

 

[mourip]

One reason that you might not want to use a glass lily pipe with a sump is that it is a good idea to drill a hole in the return just below the water line to create a siphon break for when you turn off the pump or have a power outage. This is not an issue with a cannister filter.