Brown Algea taking over tank

[dueces]

Recently I changed my filter media and my lights. Around that time I started getting brown algea all over the tank. It was on the sand bed but now it is all over the glass, rocks and my corals. I have check water and it is fine. Nitrates, Calcium and salt are all at good levels.
Does anyone know how to treat this? I can post pictures if it helps

 

[yosemite sam]

A picture would definately help. What is the algae like - slimey, hairy, etc.? And it's growing on your corals too? Can you post all your water parameters, please?

 

[sleathorn]

I get the brown algae when my lights need replacing. When I replace my lights I normally buy some more snails and hermit crabs. The brown algae then disappear for me.
I would have first said change your lights, but you said you did. So, try getting some more snails and hermit crabs.