We have five tropical mollies in a ten gallon fish tank. There is some strange white, almost translucent debris that has settled over the gravel at the bottom of the tank. What is that?

I don't know but have seen some really gross fish tanks lately. Doesn't anyone know how to use an aerator for fish tanks. It is much healthier.

Do you have snails? It could be their eggs.
It could be a growth of bacteria and algae.

Do you have any water tests to test the water with?
How long has the tank been set up?
What does your routine maintenance consist of?

Maybe it would help to change 1/4 water and add some stress coat