my clownfish keeps twitching

[foggy_mind]

Also, make sure your heater isn't malfunctioning. A slight temp fluctuation can stress them out. What brand are you using?

Yeah, heaters can be sketchy. I've had a few fail on me over the years. Always good to have a backup.

[threeSixZero]

I've heard some clownfish just twitch more than others. Could be a personality thing. But definitely rule out the other stuff first.