My top tank. It 5' off the floor so it's bare minimum sand. My plecos poop was full of sand,
The pvc pipe in the back pushes every thing towards the front glass.
The vertical pipe pushes poop towards the airlift, on the opposite side.
The baffle contains the up flow scrubber, the small front hole with the plastic mesh. Is 400 gph full suction.
Fish just loved swimming in and out when fry. The plastic mesh was to prevent that as it takes a while to get them out. It is adjustable, when the fish were fry it was very low flow. Their is a 8x8 filter floss section, that I blocked off to increase suction, at the 1/2" hole. To pick up plecos poop.
The vertical tube in the back is an airlift built with vinyl tube.
All the water passes through the algae scrubber, a lot of the poop gets pulverized in the turbulent air bubbles.
A 400 gph submersible pump with 8" 0f head. Pushes the water through the basement, 55 gallon drum, and through a fluidized sand filter. Back to the top of the aquarium. Where the filter socks, floss box are, after mechanical filtration, it's all gravity fed into the horizontal pvc pipe. In the top picture.