Review on Enhance Water Filtration with hygger 6.2-Inch Large Aquarium Filter Media - 7.9 LBs 40-Pack by Jennifer Collins

I received 1 box and then 2, the stones didn't break, the second was in a slightly different packaging but it didn't matter. , or flat. They are a little over 4 times as long as they are wide, I put over 50 on the end under the sump filter box and then put some on edge/flat to the front to allow the others to stand. I think the water entering the sump drains into the holes and around the edges of the vertical holes for maximum bacterial penetration and filtration. Although ceramic/brick, they are light and strong currents can push them, especially if you try to stand them up. Properly tuned, they are stable and stay in place. I also have some round ones, they are complementary, a bit wider and stack differently, both are the same length, I have more of them (square/rectangular) in the palette.