stablizing water levels in refugium

[emoutz]

Im having a problem keeping the water level in my refugium up - the result being that I have to turn the pump off once per day or add water to keep my pump from running dry. This is my setup:

lifereef overflow box (rated at 700 gph) > 20 gallon, 3 chamber sump > quiet one 4000 (rated at 1000 gph) w/5 ft head and two elbow pipes.

I've got ball valves on both the drain and return. If I choke the pump pretty hard, I can keep the water level somewhat even (i.e. I have to refill the sump once per day rather than once every hour). However, it seems like I'm really not getting as much flow through the system as I'd like if I do that.

Any suggestions? Should I buy a smaller pump (one that might have to play catch up with the overflow for example?).

[Dubbin1]

Sounds like the only thing happening there is water evaporation.

[drunktank]

i dunno if thats evaporation, esp if u have to fill it up every hr when the pump is running full. Seems like the pump is just draining the sum- evaporation shouldnt be that quick unless the waters being heated up, and the heat would be caused by an internal pump maybe? Just a thought

What kind of pump is it and is it internal ?

[emoutz]

its a quiet one 4000 and is internal. Tank temp is stable at 80. The tank is a 90 gallon and the sump is around 20 gallons.

I doubt evap is the culprit - it could be - but I wouldnt expect the sump water level to drop several inches in a 12 hour period (esp. at night when evap tends to be lower b/c the main lights are off).

[Mark426]

Either overflow is too small or the overflow plumbing too small. You have to get some more water FROM the aquarium for your sump to keep up. I would work on getting more water from the overflow and keep my pump as it is.

[emoutz]

I asked Lifereef about my problem, their reply was that the pump/overflow combination was fine (if the pump was choked back a little) and that the problem is:

"As for your sump running dry this means that your sump does not have enough volume of water to be pumped into the main aquarium, a common error that many make. Your trying to move more water than your sump volume will allow."

Thoughts? I dont believe this is the problem: (1) it is 20 gallon sump flowing 700 ghp or less - isnt that pretty much par for the course?; and (2) if the input/output are balanced, the size of the sump (assuming it is within reason) shouldnt matter. But more sump = more leeway with respect to matching the flow rates.

I think I might just try to find a flow meter, measure what the lifereef is actually putting out, and find a pump that will return that exact amount, or maybe a little less.

[Dubbin1]

emoutz your setup sounds similar to mine and I loose about 1.5g a day to evaporation so keep that in mind when you are fixing this problem.

[emoutz]

Findlay oh huh? I went to undergrad at ONU - prolly 20 miles from there.