by Spider » Thu Aug 08, 2013 5:10 pm
Sounds to me like if you need that much perfectly clean DI water investing in a serious RO setup would be the way to go. Huge amount of wastewater though. I've seen units that can be mounted on the wall and plumbed in, that sit there and fill up cisterns or 55 gallon drums. I had a small one I got for cheap set up next to the washing machine, so the waste could just go down the same drain. It barely kept up with the fish tank though.
Probably best to just buy this stuff rather thank kit-bash it together.
If you want to rig it up to fill a drum or whatever, you could probably use a float valve like in a toilet tank and make it fully automatic.