Is it evaporation or something else?

[appacalypse]

Hi, thanks for your time. Just a quick question.

My overflow is rated for 600gph and yet my magdrive pump does 950gph (not accounting for head pressure)

I've added a ball valve to match the overflow and return the best I could.

My question is, how can I be sure the rates are exactly equal?

In other words, if the overflow is doing ~ 600gph (maybe less due to the use of elbows) and I tried to match the pump at ~600gph, if the return is off by a few gallons, then after a while (few hours or days) the difference will accumulate and change the sump level.

How can I know the difference between a case like this and evaporation?

Thank you for your help and time.

 

[sfin52]

Mark with a marker where you want your water level.

 

[theMeat]

Hi
It no workie like that.
The return pump controls the amount that comes back down to sump. What goes up must come down. As long as you don’t go above what the overflow can handle

 

[GabeM]

The overflow will allow flow out of the display tank for up to 600 gph. That means as long as your flow from the pump is less than 600gph then it will take care of itself.