Drainage is great, the hydroton underneath has no collected water in it that I have ever seen.

The tank has a partial screen partial glass lid on it. I doubt the humidity stays very high because the soil dries out somewhat if I don't spray it with water every couple days.

I have seen fungus on my houseplants which are all well drained. The humidity in my part of the state is HIGH for most of the year. Mold and fungus are an every day challenge so keeping mold and fungus out of anything that has a favorable growing environment is almost impossible.

I hope to be able to pick up the rest of the supplies to set up the new tank today. The frogs seem healthy right now.

Only thing I can think of for what caused this specific fungus outbreak would be adding wild caught isopods. They might have transported the fungus.

I guess the only good thing is the frogs are local species and should have dealt with it in the wild. I have seen similar white/yellow mold on wood and under logs but never the dots. Then again, the dots were more under the soil and the white and yellow film only formed on the top.

Hopefully it won't be a tiny fruit and I will be able to remove any true mushrooms that grow before they can develop spores. Exposure to the spores for people can't be any worse than breathing the air outside this time of year and it only gets worse util it dries out sooner or later, hopefully.

Maybe the fungus just wants to be part of the largest living organism in the U.S. that grows from Canada to Oregon underground, wish I could take it out and let be part of it instead of in my tank.