Green Algea...HELP!!

[dc8053]

I have a 75 gallon reef tank that is 2 years old and fully established. FOr the past few weeks I have been getting this Dark Green Algea growing on the surface of the sand/crushed coral and only on that. I can't seem to get rid of it, any suggestions. My ph is 0, Nitrite 0, Nitrate 0, Ammonia 0, Phosphate 0 and Calcium at around 550-600 ppm. Any suggestions would be greatly appreciated!! Thanks.

 

[andymi]

You might want to take a water sample to an LFS and have it re-tested for phosphates. Also do you have a cleanup crew in the tank to help eat the algae? You also might want to look at getting some macroalgae which will often (in my experience) help reduce some of the nuisance hair and slime algaes.
--Andy

 

[burnnspy]

I agree wit Andy, I recommend using a different test(Salifert is my choice) for Nitrates and Phosphates.
BurnNSpy