Thanks for your insight! On the contrary, my IOS tank flooded a couple of times due to choked filter wool. My tank produces a lot of "slime", and I need to change the filter wool twice a week. I still haven't found the root cause, and I was hoping having a sump tank would help a little. Besides, all the equipment and wires are all on top of my work desk at the moment, which is very unsightly, so keeping all these underneath makes a neater workstation. There are pros and cons to keeping a reef tank in the office...