diatoms brown slime algea

[leeks]

I never had this untill i moved the tank. The tank is three years old. the skimmer is working over time. I use carbon and strong water flow the more you mess with it the faster it grows. some corals are getting covered i keep brushing it off .and it is all ro water. any suggestions.

 

[MattM]

If it's slimy then it's probably not diatoms. They usually show up as a thin film on the glass or sand/rocks.

Are there bubbles trapped in it? Does it grow back within 24 hours after being siphoned?

If yes to both, then it's probably dinoflagellates. These are bad news. The main key is don't go crazy trying to fight them. Raise KH (5 - 8 meq/l), keep pH high (8.2 - 8.5), limit lights to a couple hours a day or turn off completely for a few days. And finally, patience. It will go away in time.