Using waste r/o water-anyone???

[falcon]

Is anyone using waste r/o water for w/c? At present, I am mixing tap and r/o water for w/c. What about using waste r/o for the tap component and then mix it with r/o water. Is is safe? Does anyone water parameters of this waste water?

Just a thought. If r/o removes tds and other water byproducts wouldn't using waste water be adding them back in concentration?

Any input would be appreciated.

falcon

[Bmeasure]

I would agree with your theory. I have never used wast RO, but it makes logical sense that it would be more hard than the original input water (higher tds). I would think that as long as you have relatively neutral water (between 6 and 8 pH) and/or not "liquid rock" starting water, then perhaps the waste from the RO could be used (maybe even diluted with tap) for hard water species. Lake Tangangikan species generally prefer a pH near 9.0 with significant water hardness, so maybe this is a way to produce better water parameters for these fish in certain situations. I'd do tests on the waste water and check as many of the parameters as possible for usefulness. PH, hardness, KH, phosphate, or any other solids are possible candidates.

[Z Man]

I will state my results again but first you MUST have some type of water hardness tester. I use an electronic TDS (Total Dissolved Solids) purchased for about $30 if I remember correctly. My tap water is 175ppp TDS, RO water comes out at 0ppm and the so-called waste comes out at about 190ppm. If I mix properly I can attain any TDS I want mixing both these waters. The rest of the waste I use for the other tanks, cooking and morning coffee theryby using most of it without wasting much at all.

[falcon]

Thanks guys. So it appears that you can re-use the r/o waste water. Could you use it also to reconstitute the r/o by adding back some of the minerals. I'm looking for ways to minimize waste. If I can make some r/o water, add some waste water to reconstitute it then this could work. Right now I am mixing 50/50 tap to r/o ratio. If I can use waste water in place of tap it would be even better.

I didn't realize how much waste water there is until I got a second r/o unit just for the fish and hooked it up to a sink for a temporary hookup when filling up a storage tank.

I've read somewhere that if you use DI filter, then you don't get any waster water. True?

thanks