Yea, i just use aquaclear 50 on it. The back refugium is removable therefore you know it not tightly fitted. When the water goes into the first chamber down the sponge into the second chamber with the biological filter and then back to the last chamber with pump back into the display tank. The problem here is the seal is not tightly fitted with refugium and the back wall so the water running from chamber 1 don't run through all the mechanical filter it just goes through the leak into chamber 2 same with the water in chamber 2, it leak into chamber 3, so most of the water barely even pass through the filter media, so it not filter probably and then the slot for the heater in the bottom of the chamber suppose to have water from chamber 2 running through it but instead there gap which allow water from display tank to leak through and then pump back into display tank which completely bypass first two chamber with the filter media. This might sound confusing but most of the water barely touch the filter media. I remove the back chamber and the acrylic that hold it in place this gave me alot of extra space to add my driftwood.