Ok FLL,
I don't think you're looking at the right specifications. You need to look at the power consumed, not the power produced (HP). I decided to use about 8 minutes of my life to help you a little. I looked up a 1/6 hp sump pump
(
http://www.littlegiant.com/framenav-pumps.html ) and found it rated at 5 amps 120 V. Putting on my engineering hat I know that :
P(Watt) = V(volts)*I(current)=120*5
= 600
watts. (You pay the electric company for watts used)
I also looked up a 1/2 hp ice eater (
http://www.marine-electronics-unlimi...ater+P500.html)
and lo and behold it also was rated at 120V 5 amps which calculates to be 600 watts, more horsepower, same energy usage. The ice eater claims to have an energy efficient motor, while the sump pump is cheap. Now the purists out there may argue that these are rating numbers and the 1/6 hp motor may not actually use 5 amps, I don't care, because during my 8 minutes of work I found a solution that should pay for itself quickly. Its called a Dock Bubbler (
http://www.dockbubbler.com/Dock_Bubbler_DB40.asp) the model for a 30 ft dock uses 47, thats forty seven watts of power, one twelfth of the power of your sump pump or ice eater, saving you mucho dinero per month.
Its similar to the system Jimbob talks about although the sticker price for all the parts is $525.00.
So if your looking to save money in the long run forget about the sump pump, buy a system like the Dock Bubbler, their sales pitch says it works great and if someone took the time to write it down it must be true.
Does anyone use a system like this??