I've been doing 1% changes on my system for over 2 years. I love it. If it wasn't for that I bet I'd be one of these guys doing 1 every year, lol.
Check out my build:
http://www.canreef.com/vbulletin/sho...us%27s+upgrade
The pump I use is on pg 13 post # 126. It's got a matched dual head pump so what is taken out is exactly what's going back in.
And the ATO water and New Salt water tanks it gets it from are on pg 16 post 158.
I made the decision to go this route based on this article:
http://reefkeeping.com/issues/2005-10/rhf/