i have the model 2.... well had. i didnt like it. I thought it was waaaay to small. If you want a fuge style your skimmer and return need to go in the third chamber. Which then makes it very to put in anymore reactors like gfo, carbon or kalk. I upgraded to a trigger system sump and i love it. plenty of room for reactors, return, and my heaters in the third chamber. The first has my skimmer and some live rock and it also has holders for probes, the second is a fuge.