White powder/slim on fish

[newhobbist]

I've noticed that my Black Molly has a white spots on its body. I'm sure that this is not ICH. These spots are small and not cotton-like so I'm not sure whether it is fungus or not. Additionally, there are larter area (almost whole head) covered in something that looks like white slim or very fine powder.
Today I found that my Rainbow Shark has similar simptoms. Both fish swim at one spot and move only when I feed, though they eat without their usual hunger.
Water parameters are normal with amonia, nitrite at zero and nitrate at 30. I change water every 7-10 days. PH is 6.5, and temperature is 79 degrees.
What can it be and how to fight it?

[severum mama]

Take this for what it's worth, as I have no direct experience with this disease, but this sounds like velvet to me. Maybe if you post in the unhealthy fish forum you could get a recommendation for a med. Good luck.

[FishFingers]

Sounds like velvet to me try this site:

http://www.fishpalace.org/Disease.html#Velvet

Hope it helps.

[malkore]

white spots would either be ich or velvet. Confirm which it is (since ich is more common, but velvet isn't exactly rare) adn then treat accordingly.