We have 6 neons, I've noticed twice when turning on the light in the tank in the morning 1 of them looks like it's dead, floating on it's side going up in the bubble wall. It looks completely lifeless, but both times right when I get the net it takes off & acts completely normal. 1st time was 4 days ago & then again this morning. I'm 99% sure it's the same neon, it's a little bigger than the others. Anyone know what this might be? Thank you