40gal breeder with sump

[coraline23]

I am in the process of setting up a 40gal breeder tank with an eshoppes eclipse M overflow box. I was planning on building a sump with a 20 long but someone mentioned I would be better off with a 29 gallon in case of possible overflow issues if the pump failed. Is this true? Thoughts / suggestions?

 

[ichthyogeek]

Hmmm, it depends on the pump etc. Most sumps I know of don't operate at 100% fullness, but if they do, and the power goes out, chances are high that an overflow issue might happen. The best thing to do really, is to operate the sump at a level where, if the power goes out, the water won't all drain to the sump and flood the floor.

You can achieve this through, when setting up everything, simulating a power outage. Before you plug everything in, fill the 40B, and the sump halfway full. Turn everything on, get the overflow primed, etc. Then turn everything off. Wait for about an hour or so to figure out how much water drains through to the sump. You can (optionally) then add more water to fill the sump, and turn the pumps back on, to see where the "safe" limit is for when adding topoff water, etc.

 

[R.Weller]

If both tanks fit in you space, then use the 29. You’ll be pleased in the long run.

Irrespective of the overall size of the sump, you’ll want to calculate the volume of your return chamber when you set the baffle. How many gallons does the overflow box hold & how long is your plumbing? Assume this will all drain out when power is cut or when the return pump malfunctions. Both events are likely to happen over the lifetime of your system.

Are you planning on using a kit or will you be installing glass baffles? The kit will provide some flexibility to adjust over time, but we have always used glass for DIY sump builds.