I'm going to get river stones (the tumbled smooth rocks) from a pet store. and silicon them together to build a sort of box around the pump. Then silicon a screen to the inside of my stone pump box to keep sediment out and attempt to reduce blockage. And to my understanding it wouldnt take much to stop the flow of a slow moving pump. As to a higher powered pump that could tolerate a little more abuse. I plan to do my best to double the screen between the gravel pit beneath the dripwall and my false bottom to further my attempt in keeping the sediment minimal around the pump. I've even thought about siliconing the bottom layer of stone in place to the glass and make screen walls through the return to the pump. I'll try to make another sketch of what I'm trying to explain when I get home in the morning.