cloudy layer on water res (pics)

This cloudy layer forms on top of the water after 3 or 4 days of changing the water. Is there any way to prevent it or get rid of it? It seems that whatever it is, it is effecting the plants leaves. I took some pictures of the water, went over the top layer with a black knife and the leaves.

The plants are about 3 weeks old, it's a hydro drip system with clay pepples.

There is also white salt looking stuff around the rockwool. Is this actually salt? How would I go about getting that off there if it is even harmful. I tried pouring fresh water on it but it did not help.

Thanks for the help..

You have mold growing on the rockwool. Completely cover the rockwool with hydroton so no light can get to it and mold wont grow. It needs light grow. Is your reservoir free from light too cause that may be the same problem.

damn mold! I hate mold! I just bought more hydrotron a couple days ago so I'll pour that on top. The reservoir is also transparent so I'll wrap it with aluminum foil and cover the top.

Thanks for the help, I'll update how it goes.

no problem, sounds like that is likely the problem with the res water.