Dennis,
Good point. It's all a trade off. We have developed a strict protocol for minimizing the opportunities for pests to be introduced. Along with your point, we are wanted lots of open space and wanted to keep the rock off the bottom of the tank. Currently very little rock is touching and the concrete allows us to make spacious formations that rise up from the bottom of the tank yet are stable enough to handle the high flow. I'm not happy with the sump performance so we are re-engineering it to better handle the pumps. Here is a sketch.
Rob
Good point. It's all a trade off. We have developed a strict protocol for minimizing the opportunities for pests to be introduced. Along with your point, we are wanted lots of open space and wanted to keep the rock off the bottom of the tank. Currently very little rock is touching and the concrete allows us to make spacious formations that rise up from the bottom of the tank yet are stable enough to handle the high flow. I'm not happy with the sump performance so we are re-engineering it to better handle the pumps. Here is a sketch.
Rob


