RO/DI cartridges chances? How often?

It depends on the level of chlorine and other impurities.  I replace sediment and Carbon every 6 months.  Ro membrane and DI are replaced only when needed (get you own TDS meter!).

The danger is that if the carbon becomes expired even for a couple days then chlorine will make it through to the RO membrane and destroy it. 

Quote:

Originally Posted by scrapman 

I have been running my RO/DI system (3 cartridges) for two years. Everybody seems to be happy.

Twice a year I have a service coming to my house (my water comes from a well) to service the house system.

They also check my RO/DI water.

They say it's OK>

Should I take their word for it?

How can I check myself the purity of my RO/DI water?

Thanks

I would never take anyone's word for anything in this hobby.

When they say it's ok, that could mean a wide range of things. Mostly I will go off what the EPA says is "OK". The EPA has a standard of what TDS is safe for human consumption. That number if I remember correctly is around 500 TDS!!! Here in Las Vegas our number is in the high 400s. Now this is usually a result of additives used to purify the water, however, these are chemicals we do not want in our tank. There is also metals and other things that are included, EPA regulates "maximum levels" of what can be include in your water. What that means is that while certain things cannot be in the water at all, some are allowed at low levels.

So with that you do not want them in your tank, will these chemicals harm fish, most won't at the standard drinking levels, with the exception of a few that are treated with water conditioners. However, their are chemicals that algae love.

You stated that you have well water, there are chances that chemicals from surrounding land leech into the water. However, as long as these chemicals are lower than EPA standards, the company can stay your water is OK! I personally find it hard to believe that changing your filters out after 2 years that you are getting 0 TDS. Secondly, are you positive that you have an RO/DI or just an RO. 3 Stages are usually just RO.

I agree.....I find it very hard to believe you've gone 2 years and no filter changes.....Possible on the membrane, but I'd be curious if you did put a TDS meter on your water and see what your getting......

Yep.........RO/DI unit......

A nice handheld unit for $22.00, or this......

A mounted TDS meter that will monitor your incoming water source with 1 lead and the other lead is hooked to your output water.  $29.00

I forgot to add this link to my post: Some of the effects of the minerals in water are scary.

http://water.epa.gov/drink/contaminants/index.cfm