strange oto cat behavior - dying but I don't know why

[hbeth82]

After doing a water change this evening, I looked up to see one of my otos shoot up towards the top of the tank, then slowly drift/fall back down. He'd lie motionless on the bottom, then do this again and he's done it several times. Any idea what could be wrong? I noticed one flitting around the tank earlier, more spastic than I'd noticed them act before but am only assuming that it was the same fish. I've also lost two other otos in the last 5 weeks. I have green algae growing on the glass and they get bits of algae disc a few times a week, so it couldn't be hunger. I've also lost a grourami showing dropsy in the last 2 weeks.

Ammonia & nitrate levels are at 0, nitrate stays below 20 ppm.

Any advice is appreciated.

 

[joy13]

Considering what the oto goes through before making it to the store it is amazing any live. They are all wild caught and most aren't fed much until they are sold so are probably starving to death when we buy them.

 

[AshleyXavier]

Perhaps you can check the water you use to change, what type of water, how much you change, etc. Most people will need more info to help you.

As for buying Otto Cats, when buying from shops, choose your otto carefully. One easy indication is to look at their stomach area, if it is flat or drawn in, it's probably starving, weak and will not be able to survive well in a sudden change of enviroment or water.

The healthy ones who have eatern well, the stomach tends to be more rounded.

 

[hbeth82]

I'd had these otos for 5-6 months and other than one death in the first week, everything had been okay until 5 weeks ago. I'd felt pretty good about that at the time.

As for water changes, I use tap water and change every 6-8 days, taking out about 30%. The nitrate in the tap water is about 7-10 ppm. I use the Aqueon water change system so I think that should cut down a little on the stress, having water coming in as a steady stream rather than cups being dumped. I usually add Prime to a small cup of water and pour that underneath the filter returnflow.

I'd noticed the frantic swimming several hours prior to the water change but I can't profess to know it was the same oto, though I'd only had 2 at the time.