i did a 40% water change this afternoon...checked the water before and after, everything was normal...now he's doing worse, he finally made some movement but swam to teh top of the water did about 20 fast circles and then floated down to the bottom...then after a second recovered and swam behind a log and is still sitting there...he has lost 70% of his color, his scales look white/transparent almost like there not there...any idea whats wrong?? is there any kind of "general medicine" i can give him??? he needs it NOW!!! please help if you can