Sump Evaporation Is Really Fast!!


My sump in my 75 gallon FOWLR evaporates really really fast! It only takes a day for the water level to get close to the return pump, which is bad because if the pump is exposed to air it starts shooting microbubbles everywhere. I keep my light off and I put frozen water bottles in there as well, but the evaporation still occurs. I don't want to be topping off my tank every day. I also open my lid cause I heard the tank will stay cool that way.

Is this normal? Can I keep it from evaporating this fast? Is it even evaporation?


It's either evaporation or it's leaking. The lower the humidity in your house, the faster the evaporation. If you want to slow it down you will have to keep the tank and the sump covered.
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I agree with John.
It's pretty normal. You'll experience evaporation from any exposed surface. That means the display and the sump are both areas for evaporation, especially the overflow areas (overflow weir, baffles etc).

I was experiencing about 1% evaporation per day (0.5G), and just had to top off daily. There's not much you can do about nature and science.

You could consider adding a humidifier into the cabinet, or putting lids/covers over the sump and keeping the hood down will help reduce evaporation as it contains the humidity. Unless you've got a problem with temperature.

The last option is an auto top-off (ATO).

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