Hi Gary,
I have been harvesting off my unit roof, circa 2000 sq ft for the last 6 months. Just topped using mains for the first time tonight.... Both 1000l IBCs frozen.... Grrrrr... My tds is 9 from the roof but still ass it through a particle filter and a 22L DI unit to give me 000tds.... Perfect, quick,simple and cheap!!!!
Cheers
Matt