Overflow and Sump Question

[Maverick00]

it all depends on quite a few factors

-how high you run your water level above the overflow inlet
-how much pvc you are running
-where your siphon stop hole is located on return nozzles

Id recommend running sump as low as you can and simulate a power outage, then you mark out how much higher the level has raised and adjust accordingly

for an example on my 33gal, ill lose only a few gallons back into the sump if the power goes out.