Want to buy small RO/DI

[9fishers]

If anyone in south Atlanta has a small (less than 50 or so gpd) for sale, we might be interested. Must be in great condition with no repairs needed. Thought we could get by without one....wrong. Have a wet/dry filter I could toss in.

Anyone???
Thanks,
Nicole

[nate-g]

how much are you looking to spend? The reason I ask is that I bought a very nice 5 stage 75gpd RO/DI from AquaSafe systems out of canada. They have an ebay store and the complete setup runs $100 for buy it now. Or you can risk bidding like I did and win the system for $80. Very low TDS and nice quality components. Uses a Filmtec membrane just like all the others.

Nate

[Cobalt]

I have a 30gpd unit I might consder selling if I pick up percula's unit. It all brand new filters and an extra carbon filter. I'll post here soon...

[9fishers]

Cobalt, 30 gpd sounds great! As far as how much $$ to spend????? Dont want an off the shelf one because I dont want an off the shelf price. I am really hoping to get a good used one for less. I also have a wet/dry sump I'd toss in.

Thanks for the replies,
Nicole

[phishschtick]

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. Use can always test with a TDS meter or conductivity meter though.

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.

Just a thought - Dale

[georgiajams]

The TFC membranes used in most models cannot come in contact with chlorine.

You are saying you should just make sure that the filter has been run with carbon the whole time, right?

[phishschtick]

That is correct. A TFC (thin film composite) membrane cannot tolerate chlorine as it will damage its rejection capabilities. Carbon is used prior to the membrane which removes the chlorine. I don't know, however, how to test the effectiveness of the carbon and when it has been exhausted. Therefore I replace the carbon block every 6 months for the heck of it. Can anyone comment on a better approach?

Some equipment manufacturer's offer a CA (cellulose Acetate) membrane that is chlorine tolerant but then you're dealing with bacteria issues that will eat the cellulose. So stick with the TFC and you must use carbon as a prefilter.

[Cobalt]

Sorry Nicole, percula's unit sold so I won't be selling mine.

[9fishers]

Thanks, anyway, Cobalt.

Nicole