Jim,

If you havn't already, try to find out what the TDS is in your area. That's the Total Desolved Solids. You can find this number by calling your water company I beleive, or your local Culligan company. The lower the number, the longer your DI tanks will last. That will impact your price greatly, and quality somewhat. I know there are some wc'ers that use a wfp a lot on resi. Carbon fiber poles help with weight slightly, but are expensive.

Micah Kommers
We Wash Windows www.we-wash-windows.com
South Carolina