R/O question

[shawmutt]

I'm still trying to compile a budget for a salt water tank, and was researching prices on R/O systems. One common phrase I came across was "waste water." Apparently some systems have 5 gallons of waste water for every gallon of R/O water. Here are some sites I found:

http://www.algone.com/reverse_osmosis.htm
http://www.owaters.com/rev-osmosis.php
http://www.aquatechnology.net/frame426316.html

I didn't realize that these systems flush water down the drain, I thought that the water sat in the R/O unit and was squeezed out of the membrane, sort of like my brita filter--the filtered water trickles through, there is no waste. Can anyone verify this info?

 

[BillyZ]

you are correct. RO filters generate both clean water and waste water. and typicaly much more waste water than clean water.

 

[kribbz]

is the waste water good enough to drink or is it just nasty water?

 

[RogerMcAllen]

It should be drinkable, just taste really bad. If you get 1 gallon pure and 6 waste, that would be the same as taking 6 gallons of water and boiling away 5. The remaining 5 would be good, just not as good. I might be completely wrong here, but my logic seems to make sense.

 

[shawmutt]

That seems like a huge waste. If I had a 46 gallon bowfront reef tank (that's what size I'm looking into), I'd have to change 9 gallons of water every other week. I'd be wasting 36 gallons just to do a 20% water change! Not to mention the times I'd have to top off the tank, from what I hear in here around a half-gallon a day! There has to be a better way...

 

[fishfreek]

In some tests i saw someone do of TDS on waste water it was just a bit more dirty than their tap water.

I use waste water to do my laundry with. Others use it for plants. Others use it for freshwater tanks (i have done this also).

How about us with larger and more tanks. Its not as bad as you think. An average morning shower goes thru more than 36 gal of water i susupect. Most of the time when you fush uless you have a new water savor toliet you use upward to 5 gal of water.

 

[dustybrannum]

So what is a good choice on ways to obtain water that wont cost an arm and a leg per month? I was looking at a 5 stage RO at Sams club for 149.99 with a 3 gallon tank. It never said how much it produced a day. I inferred from one comment that an RO/DI would be better than just an RO, is this correct?