Gravity Fed Fluidized Bed

I made this fluidized bed filter out of some polycarbonate scraps. It has large grain sandblasting sand so the bubbles from the gravity fed water doesn't eject the sand into the sump. Holds about two gallons of sand. It is not fully fluidizing at this point but all the sand is moving. The holes are left over from the sides being aquarium lids. Most of the water flows out the sides that form the angled sides. I'm working out the kinks of an air purge system to so I can put finer media with more surface area.

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