Help!!

[nufishlover]

My Cory Spongebob just died and now my Cory Patrick is acting wierd. I never saw Spongebob acting this way-i just came one one day and he was sucked up against the intake filter dead. I put Patrick in a quarantine tank and sometimes I think he's dead because he's lying on his side then he's up swimming around and eating. Then I thought he was dead again because he floated up to the top of the tank very still like then he'd swim to the bottom and start over again. He did this a few more times then he started acting normal again. He has no abnormal outward appearance except he is a little darker and I know that can be a sign of illness. Today I came home and he was lying on his side but when I touched the tank he was up swimming again What should I do? The Water tests fine and I have had ten gallon tank for 9 mos. I do 25 to 30% water changes bi-monthly. I have 5 Zebra Danios and 4 Neon Tetra's that seem fine. The Danios are food hogs so maybe the Cories weren't getting enough to eat? I did lose a pleco a few months back and I never knew why. I'd appreciate any advice. Thanks!

 

[Sea_Monster87]

Corys are schooling fish, so they can't be kept alone. I saw a cory in an LFS once that was alone, and he looked/acted like your cory is. I think he's stressed because he doesn't have another cory to swim with. Make sure he/she has lots of hiding places, and buy him another friend if possible. Also, I'd put him back in the big tank if I was you, but you may want a second opinion on that.
HTH
Sea Monster