Preventing mold...

[eebco]

I had issues with stuff growing (eek) in my tank and I think it killed one of my hermit crabs. I think my substrate was too wet initially and I had it some sun part of the day.

I cleaned my tank and put in new substrate. 5 to 1 sand to eco earth. I have 10 gallon. Heater on back above substrate. I see some condensation and I’m worried the stuff growing is going to happen again. I moved them to a new location away from afternoon sun. The temp is always 77 and humidity is between 83 and 77 always. I have the lid covered with plastic and I poked some holes in the plastic bc it was too humid at one point. All my stats are good, bit now the top layer of the substrate is dry yet I still see condensation elsewhere. I know it’s now good to have the substrate dry on top. I feel like the tank it smelly when I first take of the lid. So again ... trying to find the right balance. Any suggestions?!? I have 2 small crabs.

[curlysister]

The white fuzzy mold that grows on the surace of things won't kill your crabs. A bacterial bloom under the substrate can be harmful. Can you see any grey or green along the sides of the tank, under the sub line?