Tank clearing up??

[bjftanker]

Well after alot of trouble that i have been having with my tank it seems to be clearing up. So i have been keeping my metal halide light off for the last week or so. Now i beleive that it is as clear as it is going to get. Again my tank is a reef tank and is a 65 gallon. The metal halide is a single 175watt. But i have noticed that if i leave it on for 5 hrs or more that green algea starts to grow again. wHAT WOULD CAUSE THAT TO HAPPEN? JUST THOUGHT ONE OF YOU EXPERTS MIGHT HAVE SOME IMPUT ON THIS PROBLEM.. HOW LONG SHOULD I BE LEAVING MY HALIDE ON EVERYDAY?

 

[ostrow]

Weren't you using tap water? If so, the problem will continue.

If you have switched to RO/DI water, then it's probably a matter of checking pH and alk levels, and calcium too.

But in the end probably a phosphate problem. Feed less, increase circulation, and export phosphates (using somehting like Phosban or Rowaphos). Carbon is good to run if you don't do so, while the problem continues.

 

[impur]

How old is the bulb?