thanks Sharn, I have just lost my algae eater tonight as well it looked a little bit slimy on its belly side, the problems began after introducing 4 guppies last week I think some of the water from the bag got released into the tank with the fish and caused havoc, now I have done the formulin should I do a 30% water change tomorrow and then do a whitespot cure again, the others look perfectly happy but then again both algae eaters were out swimming with each other today and they seemed quite alright as well....