I have been using a ASM3 for the past 13 years on my 220 tank with a 40 gallon sump. But i am looking at making a refugium/sump and was wondering what a good small foot print skimmer may be. its been awhile since i bought one because the ASM3 does a really good job but it will not fit in my footprint of the tank i am going to be using. any input would be greatly appreciated.