I would cut the rock down to 40-50 lbs just to free up some space for fish to swim and corals to grow. All you really need is live rock a good skimmer and water movement to run a reef, its called the Berlin method. I have no real form of filtration on my tank. I have a good skimmer, sump with fuge area, shallow sand bed, around 40 lbs of live rock, reactor with carbon and I will fun a filter sock over my sump drain some times. I would call my set up more of a water treatment than a filter. My rock also has many different sponges that have grown that help filter the water.