I have just finished building my pvc overflow it works like a charm and am about to order my pump. I wanted to what kind of media i should use in the middle of my 10 gallon sump? My sump has 3 chambers, one for where the water flows in with mechanical filtration there, one in the middle for whatever biological filtration i put in, and one for the return. The middle is roughly 14 inches long and the water will be around 5 inches high. Also how much should I buy because it will have things in like ounces and litres and I'm not sure how much that will fill.
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