Yep, that makes more sense. It could just be a low salinity bugging the Xenia then. Personally, on a tank with either a poor skimmer or no skimmer at all, I like to to bigger waterchanges. Try doing 5g waterchanges instead.
Here's an Aqua FX RO/DI system for a very reasonable price. I have an AquaFX, and I really like it. I don't know where (or even what province) Rimbey is...
http://www.canreef.com/vbulletin/sho...highlight=Aqua