RO/DI

[alton]

To start off; I am no professional when it comes to the subject but after talking with Scott yesterday I just wanted to pass on some info. First of all I have learned Chloramines eats RO filters. I actually run three chloramine filters before my RO, and I still have to change my membrane out at least once a year. Why? My tap water is higher in free and total chlorine than my pool in my backyard. Another issue people are running into is DI exhausting way to fast. Per the spectrapure website (see attached) the higher the TDS is out of the RO membrane, the faster you will go through DI resin. Another must item for me is a triple sensor testing TDS meter, one for incoming tap, one for checking the TDS after the membrane, and the third for after the DI. Since I run dual DI, I have a meter between the DI cartridges. Once my RO membrane starts dropping from 1 to 2 it takes no time to get to 10 and my DI resin goes fast. Hopefully others will add to this with there experience and issues.

http://www.spectrapure.com/

Our sponsors (Air Water Ice and Russ at Buckeye Hydro)carry the filters and accessories to make your water quality the best, I just used Spectrapure because of the chart they have on there website

[FarmerTy]

Great info Alton. Not pertinent directly to your setup but if for some reason your DI gets spent very quickly and you have very low TDS going into the DI stage, try aerating your water prior to DI stage in a brute trash can with an air pump and then pump in into DI. Some water has a very high carbon dioxide level and that can expend your DI very quickly as well.

[Sierra_Bravo]

I have a 150 gpd 4 stage RO/DI from BRS and was using BRS resin. I had mentioned to Alton that I was burning through the DI resin, making only about 120 gallons before it had color changed and started showing 3 - 4 TDS going into my storage tank. I took his advice on installing additional TDS meters so I could see what was happening. I also called Chris at Air, Water, and Ice who advised me to change from the 150 GPD setup to running just a 75 GPD setup since I don't really need to make that much water and switch from the standard BRS 550 flow restrictor to a larger 800 in order to properly flush the single membrane. A 150 GPD would have required an 1100 restrictor. The premise here I believe is that BRS puts a smaller flow restrictor on its 150 GPD to reduce water waste, but then you are not properly flushing the system and forcing the DI resin to work harder.

I do not have chlorimines in my water supply; we are chlorine only. Currently I have around 250-260 TDS from the supply line. After the sediment and carbon filters it is reduced to around 230-240 headed to the membrane. Coming out of the membrane and after it flushes for 5 min, the water entering the DI is around 10 TDS and that is reduced to 0 coming out of the DI.

Prior to the changes I had about 30 TDS coming out of the membrane and into the DI. We'll see if it helps. I also purchased Air, Water, and Ice's resin instead of the BRS. I'll update if it helps longer term.

[alton]

10 is much better than 30, keep us updated