In my 90g (up and running ammonia and nitrite free for ~8 months), when I do my weekly water changes, the multipunctatus cats start doing some of the craziest flashing I have ever seen. Nothing happens to the cichlids. I have also noticed that the synos are much more playful recently (since spring hit), a group of five of them "playing" almost non-stop. I just attributed it to springtime and the urge to procreate (unfortunately no hosts for multi eggs in this tank). These are the only real changes I notice in the whole system. Everyone is eating, none are visibly sick, cyprochromis still spawning regularly, non-syno cats behave normally. Anyone out there have any clue what might be going on?
Water parameters are normal: Am 0, NI 0, NA ~10.
My only guess at this point is that as the fish are growing bioload is increasing and there is more fluctuation than there used to be at each water change. However, I would expect this to affect everyone in the tank, not just the catfish. Perhaps because they are scaleless...?
Thanks for any help you might be able to provide.