how often do you rinse/clean your bioballs? I am familiar with the proclear I have one on my 55, the balls can trap waste and build up gunk you need to rinse them regularly when you do a water change just fill a bucket with tank water and rinse them in there to get the crap off.oh yeah the sponge needs to be rinsed too.
since you have shrimp you obviously dont have anything thats going to decimate a good clean up crew, I would get more snails and crabs, do you know if any of your fish would eat starfish because serpent stars are great poop eaters as well as good at gettign missed food.