The water level in my sump keeps going down...

[viperfish]

Originally Posted by zoaElite

What make you think it isn't evaporation? It's either evaporation or the fish are drinking it .

[snow1]

Okay thanks, someone gave me a good answer through pm just now. Thanks all for the help and I know what I have to do so it does not evaporate so much.

[banditpowdercoat]

Problem is, evaporation is helping tank stay cool. If you cover it with a glass top, you may run the risk of overheating. As well as you lessen the oxygen exchange when covering your tank.

[reefwars]

could be global warming

[scherzo]

+1 on helping cool the tank.

You can try covering the tanks with glass.... that usually slows it down.. but then also brings your tank temperature up. (Especially when the ambient temperature goes up)... reduce splashing.. etc..

Evaporation is part of the hobby. Do a quick search on ATO or Auto-Top-Off. You'll find a bunch of solutions that people do to keep their tanks at the same salinity.

[scherzo]

Oh.. I noticed that your other tanks are FW tanks.

So you won't notice evaporation on those tanks as much because you are looking at the level of water for the ENTIRE tank.. so it seems like it is going slower.

On a sump setup.. the ONLY area that you see where the evaporation takes place is IN THE SUMP which is a tiny cross section of the tank.. so 3 inches of evaporation in your sump.. every few days is probably equal to the amount of water you are losing in your fresh water tanks.. but you are looking at a larger surface area.. so your freshwater display tank will only lose 1 centimeter...

[SeaHorse_Fanatic]

A reef tank also has higher power (ie. hotter) lights & more flow. These contribute to the evaporation. I have glass tops now on all my tanks except the main reef and that helps a lot for reducing evaporation. Some of my tanks though are fw or fowlr.

[snow1]

Well the main tank has glass tops on it. The sump does not. Not going to buy an ATO. I'll look around and find a DIY way to get the job done.