Hello to all. I just set up my 55 gallon aquarium this past Sunday 8/5/07 along with the dual ( 2 carbon cartridges) outside filter , added the appropriate amount of the Cycle ( made by Hagen) madication to the water, on Monday the water was crystal clear, I added 4 Zebra Danios as I was told it was a good hardy fish to start, but today Tuesday, the water is hazy again and one of the fish is sluggish, the gills seem to be enlarged, and its body seems scaly, the other fish are fine and swimming along. What should I do ? should I do a part water change, etc.
?
PS I tried posting this question to the " New to the hobby " site, but I could not get in. Your help will be greatly appreicated. Thank you.

PS I tried posting this question to the " New to the hobby " site, but I could not get in. Your help will be greatly appreicated. Thank you.