[mike31154]

In the not so distant future I plan on replacing my hot water tank with a 'tankless' or 'on demand' hot water appliance. Hot water tanks themselves are not the greenest technology these days since much of the time you are storing the water and keeping it warm or hot when it's not actually being used, wasting energy in the process. I'm pretty sure the system we're talking about here won't work with tankless hot water heaters, so for me it's already a non starter. I also have concerns about sending water that has been through the prefilters, thereby dechlorinated, back into the home's plumbing. TDS might not be a problem, but by removing the chlorine you've opened yourself up to possible bacteria issues, particularly when sending this waste water into a 'warm' environment. Finally, running RO systems for short bursts (as in only when the hot water tap is opened) is pretty well known to not be the best for your system. TDS creep is an issue since it generally takes a few minutes for the numbers to get down to acceptable levels after the system is pressurized.

My current procedure is pretty unsophisticated but it works fine for me and would say it is 'effectively' zero waste. I usually run the RODI to make at least 14 gallons for my top up containers, more for water changes. I have several large plastic barrels that I collect the RODI waste water in. In the summer it goes in the garden, in the winter I haul buckets to the bathroom and use it to flush the toilets. A bit of work yes, but simple without the issues I've mentioned above. Can't really use it in the washer since I have a newer front loader and they don't use very much water. May not work for everyone due to space constraints.