Missing Water?

[Denon]

Recently one of my two 75G is losing water. I have two of them right next to each other, they are nearly setup identically both have glass lids same lights, filters, etc. One of them the water level seems to be slowly dropping. I have looked all around the tank on the floor etc no water. The only area outside the tank I see that seems to be damp is on the lid at the back of the tank, but nothing on any of the seems, floor or base of the tank. The other tank does not have this slight dampness.

 

[TwoHedWlf]

Sure it's not evaporating? Glass lid not sealing tight?

 

[Denon]

Suppose it could be, but wouldn’t think it would be so much I always fill right to the bottom of the plastic brace and did my water changes Sunday. So just really odd that much is gone in the one tank and the other one shows no water line at all. ?

 

[ADawson23]

If the floor and stand are dry, it’s definitely evaporating. I thought the same thing when I noticed my sump was loosing water much faster than normal.

 

[tlindsey]

Are the temperature the same in both aquariums?

 

[FINWIN]

Depending on the time of year and the humidity in the basement + ambient air temp, I can get massive evaporation. Usually happens in the winter. Also more aeration speeds up the process.

 

[Denon]

Are the temperature the same in both aquariums?

Yes they both float between 76 and 78f On ranco thermostats and ehiem heaters.

 

[deeda]

Is the surface agitation on the tank losing water more vigorous than the other? Any home heating vents or fans nearer the tank losing water?

 

[Denon]

Is the surface agitation on the tank losing water more vigorous than the other? Any home heating vents or fans nearer the tank losing water?

Not sure on surface agitation. It could be slightly higher, which may explain the dampness on the back of the top rim of the tank. I have 4 box filters on each tank, controlled with some cheap shutoff valves into my pvc loop. Tanks are right next to each other, one is about a foot taller off the ground than the other . The one losing water is closer to the heating duct and the lower tank, but it is well above both tanks.

 

[tlindsey]

The one losing water is closer to the heating duct and the lower tank, but it is well above both tanks.

I'm not a scientist but assuming the air exchange may be causing the evaporation of higher aquarium.