Ill try that...I have to get a red light...I know its not the snails and hermits...i hear that all the time...this is LOUD. I thought the glass was cracking...it scared me. It may be a hermit in the back. I have some of the HUGE red scarlets. He may have been stuck and was pushing hard trying to get out, hitting the glass. They are strong little buggers.
Thanks,
Josh