Sump Plans & Opinions ?



Just about to endeavor upon a large build and am wanting some peoples opinions on how to 'tackle' this hurdle as its currently the only thing giving me 'grief'...

Basically I want to create an "L" shape sump with the equipment being in the bottom "_" and the refugium within the "|"...

However I want the "_" &"|" to be 2 separate tanks, connecting them is what is giving me the grief...

(ignore 'above display')

What I have drawn in the image is simply multiple PVC pipe connections however I can see multiple reasons why this wouldn't work unless it's just my paranoia ?

Also I kind of want to keep the "L" like drawn above where there is a gap in the corner, not necessary for just pipe work but because there will be a stand that fills the corner and on the stand is a large ATO reservoir, directly linked to the equipment sump below and beside it.

Any opinions ?

Would multiple PVC connections like this work and if it would, then at what depth should all the holes be for the connectors ?

Cheers for any comments :D


New member
I'm currently wrestling with a multiple sump system as well, to deal with restrictive space issues. In my case I'm going from a 125 gallon display with a 55 gallon sump to a 125 and 100 gallon tank that I want to run as a single system. I am considering drilling the existing sump at the top of the return end and having it instead fill to the top and over flow (bulkheads with pvc piping) in to a secondary sump BELOW it, with the return pumps for both tanks.. The lower level would have to be able to take the over flow from both tanks in an outage.. I'm weighing the pros and cons of doing this still though. My main reason for this was ease of maintaining the 2 as one system, using one set of monitoring equipment, versus the loss of flexibility in making different biotopes in both and and of course the risk of cross contamination..


New member
Are the tanks glass or acrylic? If glass, then is it tempered? What are the sizes of the tanks?

Getting PVC to line up exactly would be a nightmare. Not to mention the pressure on the bulkhead. If you try to drill tempered glass, it will shatter.

If you are stuck on that layout. Use hose between the connections to give some wiggle room. Why do you have some many? Are you trying to drill the side of the top tank? You probably would only need 1 or 2 at best depending on the tank size and the flowrate.

How about an overflow from the top to the bottom?

I have a 30g frag tank with the overflow going to another tank 29g and that overflow going back to the sump.

More details please.


New member
That's what I was thinking of doing with 2 sumps. Have the tanks overflow to the first sump and have that overflow to a secondary sump that would have my returns.