[phishschtick]

Preamble: I have seen a number of requests to buy used RO Units and thought I'd add my two cents. For the life of your animals a used RO system may not be your best bet unless you truly know what you're buying.... I cut this from a recent reply just incase you didn't see it.

Rambling: Folks, I work for Dow Chemical and we bought FILMTEC back in the 80's. I sold the first units to equipment manufacturers in the S.E.

The major cost of the unit is the membrane. The TFC membranes used in most models cannot come in contact with chlorine. Also if a unit has sat idle for some time the membrane itself will dry out and possibly not work as effectively as it should. You can always test with a TDS meter or conductivity meter though to see how well the membrane is rejecting ions.

Therefore when purchasing a used model, you may always want to consider to at least replace the membrane or be sure you know the circumstance of the unit (still in use, always Carbon protected (absorbs the Cl2))

I'm not trying to sell more RO units, I'm far from that business today. And when I restarted my tank just recently - I did not use my old RO membrane or Carbon. I bought new ones.

Just a thought - Dale

 

[georgiajams]

I got mine used as part of a deal with a used tank. I changed out the membrane and the carbon and filter.

One more thing to consider, I've heard that when you change the carbon, you should run the system for a little bit (30 min-1hr) with the RO membrane disconnected. This allows the little carbon particles to be dissapated without clogging up the membrane.

Next, when you put in a new membrane, let the water run through the membrane run for a while before collecting the water. I've heard up to a day. The purpose is to wash the "preservative" off the membrane. You will see some white stuff in the run off, which is supposedly this preservative.

Does all this sound right to y'all?

 

[phishschtick]

If you are using a carbon block the rinse is not as critical as you suggested, however, I'd still do it as you mentioned. Granulated carbon most definetly do a rinse,

With regard to rinsing out the membrane perservative - ABSOLUTELY!!! Time of rinse varies on size of membrane used. A full day sounds adequate.

Now I only wish I had rembered that myself. I got so anxious .... I rinsed only for a few hours as I got everything set back up and then only realized two days later that the 200 gl make up water I had prepared could have had an issue

 

[Ray1214]

I just bought a new 5 stage with uv ro/di filter for right at 130 bucks from Water the H20 Guru.