I have a 5 1/2 gallon tank and the water in the tank is deceasing...i don't know why,i have a 10 gallon and it never does this?

Can you tell me why the water is going down slowly?

What,if any kind of tank covers do you have on both of those tanks? Evaporation of water is pretty normal-The tanks that I have with openings on lids tend to evaporate faster than with the full coverage lids.

i don't have any lids now for it,i will be in a few weeks.

As Devs said, the reason why the water level is decreasing is because of evaporation. It's more noticable in your smaller tank because it's 1/2 the size of your larger tank. I have a 10 gallon with no hood, and I find I have to replace a cup or more of water every few days!

ok,now i know it's not a big deal

THANKS DEVS & IPODGIRL!