Problem with those kind of RO systems, is you have to be using water to make water.

Isn't that the same as a regular RO system? I mean once the tank is full it won't make water until you use it. Either way it's just about having the right storage tank for you needs, not really much different than a regular system.

Regular RO will make water when RO low, I mean, those ones that plumb the waste back into your house cold water line, the RO unit will only make water when something is using the water in the cold line. There needs to be somewhere for the waste water to go, and that means a household tap needs to be open.

I would assume an accumulator of some sort is used for the waste water so it can be stored when tap water isn't being used and discharged quickly when tap water is used. It's not ideal if you want to make 100gal a day but for most people it should easily meet their demands.

You would also want to discharge the waste into the hot water line as appose to the cold water line to prevent the filter from using discharged water.

This to date is the most efficient way of making clean water that I'm aware off (I could be wrong but haven't seen anything else yet). RO filtration is used in so many industrial applications and the waste created is always a concern. If it was possible to create a filter that created just as pure water without the waste or the use of an RO membrane it would be foolish to market it in home and aquarium applications. For this reason I'm pretty skeptical that it can be done. Such a filter would solve millions of industrial problems and the patent would also be worth a pretty penny, more than enough to retire on.

Why. I don't get what the difference would be from a hot to a cold line.

The RO filter uses water from the cold water line, so if you discharge waste back into the cold line the filter may be forced to reuse some of that discharge making your filter less efficient. The solution is to discharge into the hot water line so the filter can't reuse the discharged water.

Depends on where it's plumbed from I guess? if RO intake is taken from the cold, and waste is loped back into the cold, some waste water could just loop around and go back in the RO intake. But, if it's set to make water when a cold tap is open, it won't. the waste will go to the tap.


I acctually was thinking of doing this with my setup, as I am on septic and all the waste screws with the bacteria level in the septic. One thing I never figured out yet for this is if the cold water taps in house are off, there is still inlet pressure at the RO, but no where for the waste to go. The membrane now just becomes an expensive filter, and will plug real fast. No waste water to flush out captured impurities. They must use some kind of waste water presure tank and a auto shutoff on the waste line too

Technically speaking if you're using your RO water then you're using water from your cold water supply so the RO unit will continue to make more water and if the waste is plugged into the cold water supply the filter will be forced to use waste water for intake unless you happen to be using another source for tap water at the same time which isn't always likely. Obviously not the greatest solution to the problem of waste water but at the end of the day it's still the most efficient system available. This is why a new system would be very innovative and honestly if I was making it I wouldn't say a word until I had a patent in place and even then wouldn't be targeting the smallest possible market for the product. Hence, I'll believe when I see it :mrgreen:

In the mean time if the discussion is going to continue on the bases of zero waste RO we should move the discussion out of this vendors thread. I'd like to talk more about it as well and see if we can't rig up a DIY plug-in that can be adapted to all existing standard RO units.

We are having one problem.. The cost of the filters is extremely high. These filter are from the Pharmaceutical industry. Just wanted to keep everyone in the loop and that myself and our suppliers are trying to get the cost down...

well tell us how much they are if i spend 70-80 on a membrane 2x per year. and prefliters x 6 for the 1 micron and 6 and carbon 15 per pop and i use 4 of them

it will add up
is the filter life is how long thou. is this a cold sterile unit