DIY Sump flow control question

[Ksnell]

I've just built a 10 gallon sump system w/ refugium for my 20 gallon reef tank. I've got a hang on overflow box that drains into a skimmer chamber w/ live rock, then through 3 bubble trap baffles, then into the pump chamber. The return line is "T'd" too put some water into the refugium, and gravity brings that water back to the pump. My problem is that more water is flowing into the tank than out of the overflow box. I have a ball valve control for my refugium and for the return line into the tank, and no matter what I do, more water is coming back to the tank. I constantly lose water in the pump section of my sump. I know some of this is due to evaporation, but I feel like I'm loosing a lot more than was just evaporating from my tank before I had the sump. Does this make sense to anyone? Any suggestions from people who have built there own sump? TIA.

[dskidmore]

Is the Display tank filling up, in danger of overflowing? The evaporation of the system gets magnified in the pump chamber, so you may just be seeing evaporation. Under the right circumstances, evaporation can be measured in gallons per day.

If the display is getting fuller while your pump chamber is getting lower, then you really do have an imbalance. Another T with a ball valve circulating water within your pump chamber will alleviate the problem without stressing your pump. That, or if you can find an aquarium club near you, see if someone is willing to trade you a smaller pump.

[two11devan]

Got any pics of the set up?