a smaller skimmer might actualy be better. I am about to build one, and i have been reading up a lot on them. You want a realy tall one, so the bubbles will have more time in the water, and therefore, collect more waste. You will also want to get a counter current one. But a skimmer with less flow may actualy be more benificial. About 75% of your tank size in gallons. This way, the bubbles will, once again, be in contact with the same area of water more longer, because some of the bonds in the organics can take a while to break, so when the non polar charged organic waste is in contact with the polar outer edges of the bubles longer, it will actualy be mroe efficient, but i might have gotten the polar parts reversed, but none the less, from the reserch ive been doing, thats what ivefound. Im sure some people may dissagree, and feel free to. i acutaly encourage it. It might be hard to find a skimmer with about 24gallons per hour, but one rated for a 180 is a pretty powerful skimmer. Just what ive found, and if you dont agree about the flow, im sure you can agree about the length and the counter current section.