i have 8 parrot fish and a large pleco to do that for me. I will add my stingray once it's big enough.
I'm more concern with water parameter. I just found out i used the wrong type of sand (core reef sand) in my previous setup. I knew that this type of sand will increase PH but i didn't know it would make such a different with a water to sand ratio. I only use 40lbs for my 500g tank. I had it for about 2month and my PH was at 7.8. The rest is large rocks. I will test the rocks later today to see if that's a contribution my higher PH.
The new sand I've purchase is black Tahitian sand (inert) about 400lbs. i should have done this in the beginning instead of trying to find a cheaper alternative (wasted time and money). I'm trying to get my water parameter to 7.0-7.2. I'm thinking about mixing the two together since i don't want a PH drop either.