ro/di filter ?s

[vr697getta]

i have the The Optima Vision RO DI system from Purely H2O this one http://www.purelyh2o.com/catalog/Th...em-p-16134.html
i wanted to know are there better replacement filters other than Purely H2O's. where i live the water quality is not the best and i seem to be going threw filters and the membrane faster that i should. after a 2 months my tds start to climb quick.
thanks roland

[savethereef]

i always get mine from www.airwaterice.com

[crvz]

I get my from www.buckeyefieldsupply.com, but I've heard good things about awi as well.

[AZDesertRat]

The very best replacements are from www.spectrapure.com . Unlike any other vendor they have beta test units placed all over the country, actually all over the continent, and monitor data collected from those sites to determine what works best in what conditions and locations. Some of the highest sediment loading in the country is in the New York area and some of the hardest and highest TDS areas are in the southwest and Florida areas. Their filters are performing flawlessly in all those locations. Its all I use with my TDS over 800.

[vr697getta]

i looked at there site and i can't find a membrane that will work with my ro

[AZDesertRat]

Any Spectrapure membrane will fit your unit. They all have the standard TW1812-xx configuration like a Dow Filmtec. I would suggest the Select series 90 GPD, I think they are having a sale on them right now too and they are definitely a big improvement over off the shelf untested membranes. Thye guarantee 98+% rejection. Use a 0.5 micron or better yet the 0.2 micron absolute rated ZetaZorb pleated prefilter with 10x the surface area so it filters better and lasts much longer due to the additional filter area. Add a single 0.5 micron Chlorine Guzzler carbon block and your system should last much longer and work much better.

[vr697getta]

thank you AZDesertRat i will do that

[frank2926]

your problem may not be your pre filters. That is not a bad unit you have. You should not really be seeing a rise in tds with your size tank in 2 months. Your sediment filter may be clogged, you may not have enough incoming water pressure and or you could have chlorine or Chloromines in your water. I would call them and have them trouble shoot your unit for you before you go spending money that you may not have to.

[vr697getta]

yeah i will try that i really think its the sediment filters i use they turn brown quick and don't seem to last at all

[AZDesertRat]

If I remember right the Vision has an inline pressure gauge, what does it read with fresh filters installed and what does it drop to before you change them?
Either way the 0.2 micron prefilter wil be a huge improvement due to its increased filter capability and its increased surface area which gives less pressure drop.

[vr697getta]

well embarrassed to post this but i found the problem right now i am running my ro and i grabbed the wrong bucket to put the water in and there must me something in the bucket causing the high reading because in the other bucket it reads 5 and i just put it in a drinking glass and it reads 5 also but i think i will check out Spectrapure so i will get a longer life out of the filters .
thanks for all of the info and sorry for the bonehead move on my part

[Curve]

with spectrapure you will get 0 for a long time. Az put me onto them and I will always use them from now on.

[AZDesertRat]

Lets do a lesson on using a TDS meter here.
Do not test from a bucket, storage tank or other water storage container if you expect any level of accuracy on what the RO/DI unit itself is doing.
To test, first get a clear glass drinking water glass, prefferably new or hand washed, not in the dishwasher, with absolutely no water spots or soap residue. Dishwashers often leave a film and will give bad readings.
Next, grab a sample of the tap water and stick the probe in it. Let the reading stabilize and write te results down. Next, very important, triple rinse both the glass and the meter in DI or distilled water to ensur it is clean for the next test.
Now, grab a sample of RO only water before DI. This is a critical test, if your unit does not have an RO bypass valve I would highly recommend getting one. All you need are a 1/4" John Guest tee, a few inches of 1/4" tubing and a 1/4" ball valve and plumb it in between the membrane and DI. Again let it stabilize and record the results. Do anther triple rinse with DI or distilled and finally take a sample of the final RO/DI. Let it stabilize and write down the last reading. Do a final triple rinse and put the meter away clean and capped and the glass away upside down so dust and debris don't contaminate it.

Your RO membrane efficiency can be figured with the first two TDS numbers. Take the tap water TDS, subtract the RO only TDS, then divide it by the original tap water TDS and multiply that number by 100.
I will use my numbers here as an example
tap water= 835
RO= 6
RO/DI= 0

835-6=829
829 divided by 835=.9928
.9928x100= 99.28% rejection rate or efficiency.

With an off the shelf Dow Filmtec membrane in good condition I would expect to see an efficiency of 96-98%, if its much lower than that it could be costing you more in DI replacements than the cost of a new membrane.

If you do test TDS from a bucket, the sink, the neighbors or whatever (saltwater tanks themselves are way beyond the measuring range of a normal TDS meter so don't even try.) make sure you give it a good rinse with DI water ASAP so you don't ruin the probe. Never ever, (did I mention never?) put a meter away dirty.

[vr697getta]

my ro doesn't have a bypass valve but i will install one
again thanks for all the great info