Output

**PessimisticOptimist** · 02-03-2010, 05:53 PM

Quick question - how much unfiltered H20 residue, technically referred to as "The Brine" I believe, should I expect to produce for every gallon of RO/DI H20?

I have a feeling there is something wrong with my RO/DI because I am getting a hugely disproportionate amount of the former "Brine".

Please advise so I may plan and act accordingly, i.e. buy a new RO/DI, or try to rehab the one I have.

Kind Regards,

**Phurst** · 02-03-2010, 06:19 PM

I believe typical rates are around 4:1.

**PessimisticOptimist** · 02-03-2010, 07:13 PM

4:1, Brine: pure H2O? If so, what do people due with all the "Brine" What a waste of water. Is there a way to minimize the ratio.

**CarmieJo** · 02-03-2010, 08:36 PM

Some units are more efficient than others but I think 4:1 waste to pure water is average. Many people run the brine line into the washing machine or a rain barrel. Others use that water for potted plants or the lawn and garden.

**PessimisticOptimist** · 02-03-2010, 08:51 PM

Originally Posted by CarmieJo

Some units are more efficient than others but I think 4:1 waste to pure water is average. Many people run the brine line into the washing machine or a rain barrel. Others use that water for potted plants or the lawn and garden.

I'd have to have a rain forest in my house to utilize that much extra water.

On the bright site, at least now I know my unit is working correctly.

**THEJRC** · 02-04-2010, 10:16 AM

he he, I popped one of our lines out to the garden and I'm glad I did... the only issue is when we get deep freezes I've got to wait till the line thaws before I hit it up for water. not too huge of a deal as I have a second unit at another point in the house but it's something some will need to be conscious about.

A better way to test the effectiveness of your RO unit is to get ahold of a TDS meter, these range from ungodly expensive to super cheap. Even a cheap one will work. Try and get TDS as low as possible but in some areas this can be a tricky peice. Measure the TDS of your tap water, and then with new filters the TDS of your RO, that'll give you a good delta as to how well the unit is working. Over time the TDS will rise, a few points and it's time to flop out the membrane.

**AZDesertRat** · 02-04-2010, 01:32 PM

4:1 is the standard waste ratio on home use type units. This is necessary to cleanse or flush the accumulated solids away from the membrane surface. If you have relatively good water, say a tap water TDS of 100 or less and you use softened water or have low calcium carbonat hardness the n you may ge ta way with 3:1 but most of us don't have that luxury with the tap water TDS averaging around 250 nationwide.

Have you measured your waste ratio? This is a good thing to do as most RO and RO/DI units are supplied with a fixed type flow restrictor and we all know our water conditions are not the same as the next guys. Some vendors such as Spectrapure and Buckeye Field Supply use the better capillary tube type flow restrictors that you take a couple minutes and trim for your exact water conditions. This not only helps reduce excess waste but it can help produce higher GPD and even better water quality in many cases, all for less than $5! Meause both your good and waste production using a measuring cup or other graduated device and see how much you are wasting, you may be surprised how far from 4:1 it can be. Much less and you prematurely fould membranes, much more and its wasting plus not producing as much good as it should.