One of my tanks just won't stay clear. The water always has this whitish tinge. I have a 75 and a 25 that are always crystal clear. My 55 though despite water changes and gravel vacuming and too filters rated for up to 70 gallons(each one is rated for up to 70 gallons total 140 gallons) and adding crystal clear and the like it remains hazy. I have repeatedly checked ammonia 0 ppm, nitrates 0 ppm, nitrites 0 ppm and ph. Both my 75 gallon and 55 are at 6.8 to 7.0 for the ph. The only difference is one is near a window,but it's been happening since it's set-up. So I don't believe it's an algae problem, but i could be wrong. So can anyone please help me to alleviate this problem.
