Sump size

[Kfactor]

Am just building my new discus tank it’s a 75 g tank I just can’t decide on the size of sump to go with . I have 37” of width and can’t decide between a 33 g sump or a 29 g . I want to go with the 33 but will take up all the length in my sump but worried the 29’wont be big enough in case my tank back flows . I will be putting in back flow valves and stuff but don’t want to rely on just that . Was wanting some input from u guys.

[Loku]

The bigger is always the best option!

[Trey]

Hi

I am also trying to make a decision on the size for a sump....and find on surfing that the bigger the better is the advice :)

[coralbandit]

IMO the 29 will too tall to easily service .
A 30 long will fit and is lower .

[FischAutoTechGarten]

I always build my sumps with an emergency 'dump' hole at the top in the event your back flow valves fail... Of course, that means you have to have access to a drain to accept the 'dumped' water.

I agree with coral bandit.... Loving the implementing of a dual chamber sump myself made from 2 x 20L tanks. The access from above is so nice. I've done the 29gal sump before below a 120 before (run in tandem with a canister.... when I was learning...) ... just so hard to service a tall sump in an enclosed stand cabinet.

[dspeers]

I always build my sumps with an emergency 'dump' hole at the top in the event your back flow valves fail... Of course, that means you have to have access to a drain to accept the 'dumped' water.

OK what am I missing, my sump return is drilled and comes up from the bottom of the DT but the return tube runs up to above the waterline and I drilled a tiny hole at 45 degrees down at the waterline which I have assumed would break the siphon. only backflow would be the water in the return tube from the pump to the DT. Tried it, unplugged the pump and it worked, which is how I set the upper water level in the sump tank. Did not even use a check valve.

[unicast]

Yes, bigger is better :-) But don't worry, 15 or 20 gal sump shall work for you well too.

First chamber just as a gravity filter, so you can vacuum most of dirt just there. Easier maintenance.
Last chamber should be pretty big as a water reserve for the tank, during water changes, evaporation compensation etc.