Bonding two sumps together

Arsoncop · Feb 1, 2022

Hello, this is my first post so be gentle, I am attempting to build a sump for my soon to be up and going all-clam tank and frag tank, so two tanks 60 gallons total. I have two wet/dry filter boxes I had planned on using as a sump. Both have three compartments, originally I was going to use only one with a filter sock, skimmer, and return compartment. Now I have decided to add a refugium. So I need one more compartment, If I butt the two sumps end to end they will work great and I will have pretty room. Here's my question or concerns, where the two sumps meet needs to be waterproof or watertight. Because I will be cutting sawtooth slots in the wall where the two meet to allow water to cross into the next compartment. What glue, cement, or solvent should I use to make the connection waterproof and permanent?

lapin · Feb 1, 2022

The sealant would depend on what the wet dry boxes are made of. Gonna be hard to seal them.
Have you thought about maybe joining them with a bulk heads and a pipe between them

Arsoncop · Feb 1, 2022

lapin said:
The sealant would depend on what the wet dry boxes are made of. Gonna be hard to seal them.
Have you thought about maybe joining them with a bulk heads and a pipe between them

They are either plexiglass or acrylic, they are kinda older. The thought of using bulk heads has crossed my mind. But in my mind I would have to use a pump to move the water.

TheHunterYall · Feb 1, 2022

Just have it flow downhill a bit, use 45’s, 22.5’s, flexible or bend it down a hair.

Pistondog · Feb 1, 2022

You don't need much flow thru the refugium. A small pump into it, then overflow back.

flagg37 · Feb 1, 2022

Arsoncop said:
They are either plexiglass or acrylic, they are kinda older. The thought of using bulk heads has crossed my mind. But in my mind I would have to use a pump to move the water.

Just fyi, plexiglass is just a brand name for acrylic.

I think I would use the bulkhead idea. You don’t even need a pipe. Two 2” bulkheads will flow nicely. Just line up the two tanks and use a hole saw to drill the holes together so that you’re guaranteed for them to line up. Drill them fairly low and keep in mind that the water level will level out in the chambers on either side.

Jedi1199 · Feb 1, 2022

flagg37 said:
Just fyi, plexiglass is just a brand name for acrylic.

I think I would use the bulkhead idea. You don’t even need a pipe. Two 2” bulkheads will flow nicely. Just line up the two tanks and use a hole saw to drill the holes together so that you’re guaranteed for them to line up. Drill them fairly low and keep in mind that the water level will level out in the chambers on either side.

I agree with this. One thing I will say that has not been mentioned before, Use a gasket on the BOTH sides!! One under the flange on side A and one under the tightening nut on side B.

shakacuz · Feb 1, 2022

Jedi1199 said:
I agree with this. One thing I will say that has not been mentioned before, Use a gasket on the BOTH sides!! One under the flange on side A and one under the tightening nut on side B.

100000000% this!!!! when i drilled my 40B, because it was rimmed, i have to use multiple gaskets inside the overflow box because of the rim.

flagg37 · Feb 1, 2022

Jedi1199 said:
I agree with this. One thing I will say that has not been mentioned before, Use a gasket on the BOTH sides!! One under the flange on side A and one under the tightening nut on side B.

That is very true. Most bulkheads only come with a rubber gasket for the wet side. In this case there will be two wet sides. You’ll need gaskets for both sides.