i've got a 92 gal corner. and my overflow is very difficult to clean,(small area and a durso standpipe) therefor it doesn't get cleaned as often as it should. detrius builds up on the bottom and because of it i'm constantly fighting high nitrates. if i put some bristleworms in there would they survive without light? would i have to add sand to the bottom of my overflow if i did this? or should i just buy a small PH and point it at the bottom so things can't settle there?