Algae Problem

I believe you are on the right track with the rural water change Joe. It could also be the home's plumbing? I'd suggest you not go over 2 TDS at the most. You might want to get a hold of the water supplier and find out what levels are present/how they treat the water. They should have that info available. I added a 1 micron filter to my RO side and put in a second DI cartridge too. What GFO are you using? I use BRS's high capacity GFO, it works GREAT! Although it's expensive, I believe it's well worth the money as my phosphate will go from 0 , then shoot up to 10 when the GFO is spent...then after replacing it, within a day or 2, it's back to 0 ;=0)