Gear*guru,
I don't think that there is any submersible, with enough umph. I have used Iwaki 40RLXT, and 55RLT, and even the 70 in a few cases. Not many sub pumps that can hang in that company. I have an etss 600 that bangs pretty well with the largest Eheim pump. Forget which model number it is. Good luck, awesome skimmer! Mike