Hi... I have had my 180 set up for just about two monthes and have had my 8 Cariba and 3 red bellies all about 4-6 inches in length... My problem is on the top of the power heads and on the lids and inside my filters (ac 500)'s there are these small white worm like lines. They don't move at all as much as I can see. Threre about as long as this mark _ Sorry I don't have a digi. camara or I would take some pictures. I was thinking bad water but I change about 25-30 of it aweek. So that couldn't be it? I was also thinking over feeding but I always take whatever is uneaten out withen an hour. Also I feed them everynight and they eat about 75% of the food I throw in. So I really don't want to feed them any less I would think? If any of you guys have had these can you give me some idea's to get rid of them. I just added salt after my water change hoping that would help. Thanks in advance!!! Jake