How long does your DI resin last?

[Neuticle]

It seems like I go through DI resin retarded fast, I'm using about 1lb per 150 gal of water made.

Is anybody else having these results? I'm using Air Water and Ice color changing resin, so I figure it's a local water issue not a resin quality issue.

[Amphiprion]

Mine have lasted for years. What approximate TDS are you getting from the membrane? For every 1% increase in incoming TDS from the membrane, you'll get a corresponding 25% decrease in resin life.

[Neuticle]

I don't use a TDS meter, just go by the color change of the resin. Do you think my membrane is damaged?

[Amphiprion]

Either damaged, clogged, or both. Your resin should be lasting much, much longer. This is why a TDS meter is essential--not necessarily just for post-DI water, but to make sure your membrane is doing what it is supposed to be doing. How long have you had the particular membrane you are using and how often do you change carbon filters? In general, you should replace all sediment and carbon filters every 6 mos. Also using small micron ratings and sub-micron rated sediment and/or carbon filters greatly enhance membrane life by preventing premature clogging. Also, do you have a flush kit on your RO/DI unit?

[Neuticle]

hmmm, I honestly couldn't tell you if I have a flush unit. It's an ebay 6 stage system, pretty much the same stuff everyone else sells for about $125.

I know I need to change my sediment filters, it's just a matter of my memory working when I'm at Lowes. I have 3 sediment filters prior to my RO.

[Neuticle]

For the membrane flush, is this what you're talking about?

[Amphiprion]

Yes, that is a flush valve. I always flush the membrane after I run the unit for about 30 seconds - 1 minute. You say you replace your sediment filters, but are you including carbon? What is the volume rating on the carbon filters? Some of the lower end ones will need to be replaced more often, since they are only capable of filtering 1000 gallons or so. As you can imagine, that gets used up quickly and can damage the membrane before it can be replaced by allowing chlorine past. The 6 mos. rule vs. volume rule is sort of like your car before an oil change-- x000 miles vs. x date--whichever comes first.

[snoopdog]

What color does the resin turn when it goes bad ? I may need to change mine too.

[Amphiprion]

It usually goes to a brownish color. Some DI resins, especially the higher grade ones (which feature much higher filtering capacities), don't even change color. But don't judge it on color; judge it on the TDS. If the TDS is still zero out of your resin, then I wouldn't be concerned. In general, though, the resins change after the TDS values drop to more unacceptable levels.