new tank and sump

[Teamu]

I'm returning to reefing after about a 10 year break and I am planning a new tank. I know there are a lot a variables to take into account to calculate the amount of water that will drain after the pump is turned off. What I really need to know is the depth that a weir will hold back. A very conservative depth would be good enough. Being a corner unit its hard to find a good size sump that will fit. Any thoughts? Thanks!

120g corner tank
15 inch long corner weir.
Varios 6 or COR 20 pump.
1 1/4 inch return with two 3/4 inch loc-line nozzles.

 

[mcgyvr]

I'm not sure what you are asking...

But I'm likely going to answer that based on the variables a generic amount can't really be given or be useful in anyway..
The calculations to know how much water will drain are quite simple..

 

[thegrun]

There are a lot of variable primarily dealing with how you configure your return line(s) but I would plan on about 1-1/2" of drain down water (1728 cubic inches, or 7.5 gallons) if I am reading your question right. I only drain about 1" in my 120, but I configured it to minimize the drainage.

 

[Teamu]

Thanks, I was estimating about 6 to 8 gallons so that seems about right.