Thanks for the info. Do you think it would be ok to skip the eggcrate part?
I was thinking putting the piping down with holes and then then screen on top. Then placing the #2 aragonite gravel so the water could flow better at that level. Then topping it off with a few inches of fine.
My concern is that some fish might burrow down and expose the eggcrate and then there would be little to keep the fluids dissapating back into the display from the lower portion. I was thinking with this method, whatever gets dug out, the fine sand would backfill the hole.
rick