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View Full Version : Have a few questions on my Premium RO unit


basssnake
09/21/2009, 11:09 PM
I bought my Premium RO/DI unit from you about a year ago. It is the 75gpd premium. On the flush valve coming out of the membrane(the waster water port) is that valve supposed to be turned off and the waster water just running through the little blue restrictor hose? Also, how do you adjust the waste water/ good water ratio? I am not sure where it is set at now. I have never checked to see. What is the easiest way to check it if i need to? detail me


Also, on the resin, did it come with color changing resin or non color changing resin? I bought it back in november of last year. I changed the carbon block filter back in may and i recently checked the water and i was getting a reading of 1ppm. But i also had checked it in the first couple minutes of running it(it hadn't been on for a week or so). I am trying to determine when i will need to change the resin.

On the resin you sell on the website, how many times will it refill the canister if a person buys the 5lbs?

thanks for your help Russ.

Buckeye Hydro
09/22/2009, 03:27 AM
<a href=showthread.php?s=&postid=15740422#post15740422 target=_blank>Originally posted</a> by basssnake
[B]I bought my Premium RO/DI unit from you about a year ago. It is the 75gpd premium. On the flush valve coming out of the membrane(the waster water port) is that valve supposed to be turned off and the waster water just running through the little blue restrictor hose? That blue-handled valve is to be closed for normal operation - which forces the waste water to go through the blue tube. Your flow restrictor is inside that blue tube.

Also, how do you adjust the waste water/ good water ratio? I am not sure where it is set at now. I have never checked to see. What is the easiest way to check it if i need to? detail me
Line up 6 to 8 identical drinking water glasses in front of the system. With your waste water tube in one hand, and your purified water tube in the other, how many glasses do you fill up with waste water in the time it takes you to fill up one glass with DI water?


Also, on the resin, did it come with color changing resin or non color changing resin? yes

I bought it back in november of last year. I changed the carbon block filter back in may and i recently checked the water and i was getting a reading of 1ppm. But i also had checked it in the first couple minutes of running it(it hadn't been on for a week or so#. I am trying to determine when i will need to change the resin.
A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the useable life of these two filters is to use a pressure gauge to identify when pressure reaching the membrane starts to decline. This is your indication one or both of the filters is beginning to clog.

Also be cognizant of the chlorine capacity of the carbon block. The Matrikx+1 #“Chlorine Guzzler”# for example will remove 99% of chlorine from 20,000 gallons of tap water presented at 1 gpm. Original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons.

Regarding your RO membrane and DI resin, use your TDS meter to measure, record, and track the TDS #expressed in parts per million# in three places:
1. Tap water
2. After the RO but before the DI
3. After the DI.

The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 parts per million #ppm#. Common readings are 100 to 400 ppm. So for sake of discussion, let's say your tap water reads 400 ppm. That means that for every million parts of water, you have 400 parts of dissolved solids. How do we go about getting that TDS reading down to somewhere near zero?

If you do some experimenting with your TDS meter, you'll note that your sediment filter and carbon block filter #collectively called “prefilters”# do very little to remove dissolved solids. So with your tap water at 400 ppm, you can measure the water at the “in” port on your RO housing and you'll see it is still approximately 400 ppm.

The RO membrane is really the workhorse of the system. It removes most of the TDS, some membranes to a greater extent than others. For instance, 100 gpd Filmtec membranes have a rejection rate of 90% #i.e., they reject 90% of the dissolved solids in feed water#. So the purified water coming from your 100 gpd membrane would be about 40 ppm #a 90% reduction#. Filmtec 75 gpd #and below# membranes produce less purified water #aka “permeate”#, but have a higher rejection rate #96 to 98%#. The life span of a RO membrane is dependant upon how much water you run through it, and how dirty the water is. Membranes can function well for a year, two years, or more. To test the membrane, measure the total dissolved solids #TDS# in the water coming in to the membrane, and in the purified water #permeate) produced by the membrane. Compare that to the membrane’s advertised rejection rate, and to the same reading you recorded when the membrane was new. Membranes also commonly produce less water as their function declines.

After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the 40 ppm water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm to 3 ppm, 5 ppm, and higher, you know that your resin needs to be replaced. Sometimes people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin “dirty” water. This will exhaust the resin quicker than would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal!

On the resin you sell on the website, how many times will it refill the canister if a person buys the 5lbs? Each refill is about 1.25 lbs, so about 4 times.

Russ

basssnake
09/23/2009, 02:12 PM
well, my tds reading is at 1ppm out of the resin cartridge. That was as soon as i turned it on pretty much. Don't you have to run it for several minutes and then test when the system hasn't been on for awhile? I didn't know this if it is true til i read something the other day.

So, it comes with the color changing resin? What color does it turn when it is exhausted?

I haven't done the glass test to see the waste/to good water ratio.

thanks, jack

Buckeye Hydro
09/23/2009, 02:42 PM
Yes - let the system run for 2 or more minutes before you take your sample/tds measurement.

The resin changes from nearly black to a tan color.

Thanks,
Russ