<a href=showthread.php?s=&postid=7074986#post7074986 target=_blank>Originally posted</a> by Rogger Castells
You need to find the logic behind their behaviour, perhaps the ph, alkalinity or temperature are fluctuating during this events, I've also seen some negative responses to strong lighting or even a combination of things, I dunno but you must find the pattern by playing detective in your tank until you determine what it is that is causing this, once you do it will be easier to fix the problem.