These tanks are nicely built and have very clean lines. Due to the lack of surface area, Dissolved Oxygen could be an issue if you put too many fish in them. I didn't want to ruin the looks of the tank by putting a powerhead in there so I purposely keep the sump a little lower than normal so that the water has to fall into the last chamber (the return chamber). The falling water off-gasses CO2 and Oxygenates the water a little. I also have the return nozzle turned sideways so a little water goes to ripple the surface of the water and the rest sends flow around the bottom of the tank. Another thing that I'm going to do once it's in stock is to buy their Spin Stream and that will help with flow as well as Dissolved Oxygen issues. The LED moonlights are too bright and corals will not go to sleep. I had a choice.....make a nice clean light look ugly by putting some ugly electrical tape over some LED's or use a second timer just for the moonlights. Water changes are easy. I unplug the pump, take out 2 quarts and then replace it. It takes less than 60 seconds. (I have to do water changes because the black tunicate, orange tunicate, tree sponge, and feather dusters all need daily doses of phytoplankton. Additionally, the Tubastrea as well as the Dendrophyllia require target feeding on a regular basis. If I didn't keep up on my water changes, my nitrates would be 100 in just 4 or 5 days.