reasons for a clown might jump?

[Kigs]

i've just lost my ocellaris i've kept for almost a year. he had such character and he was such a great pet. paired up almost instantly with my stubborn percula too when i first put it in...

and he decided to jump out of the tank tonight. by the time i found him, he was already dry. i know i'm being stubborn here...but why would my clown jump?? did something scare him? was the female being agressive?? they always got along ... this sux.

 

[jallard]

lack of O2 maybe....ya have a skimmer or something breaking the surface tension