Used RO units...

[Semo]

Hey,
A co-worker is selling a used RO unit.

Pure-Flo II RO Unit - 50 GPD TFC - 3 Canister with Pump

This is the general infor on it..


These units feature:
50 GPD TFC membrane
Diaphram water pump
1 micron filter cartridge
Carbon block filter cartridge
GAC (granular activated carbon) cartridge

Ideal Source Water Conditions:
Chlorinated or non-chlorinated water supplies
Water pressure - 60 PSI
Water temperature range: 69 - 78 degrees Fahrenheit


The unit has been in his basement out of use for about 6 months. I am sure the membrane (along with the other 3 filters) is supposed to be changed after sitting that long.

My question is: What type of stuff am I supposed to check for in the water the unit produces? Just wondering what to offer him for it if I have to replace all the filters and membrane.

 

[Jennie]

Get ahold of a TDS meter, you can also check for phosphate before and after to see if the levels differ.

 

[TimSchmidt]

Not sure on the going rate but I do know you can get a RO/DI unit (i think it's 50 GPD or higher) on ebay for 100 bucks and they normally come with an extra sets of filters and membranes.

 

[Semo]

I tested it and all is good except...silica...I assume all regular RO/DI units don't remove silica unless its Hi-S membrane. I don't think I would need to replace the filters quite yet, but definately need something for the silica.

I know these units with the pump are 250 bucks new, but it really seems worthless if it leaves silica in the water. I will probably pass on it mainly cause I'm too ashamed to offer him <25 bux for it.

 

[RickD]

I found that whenever you purchase a used RO/DI unit, you should replace all the filters. Unless you immediately install the unit and flush the system out.


Also your DI cartridge can be used to remove Silica.

http://www.reefkeeping.com/issues/2005-05/rhf/index.php

Talk to your local water purification expert or LFS about where to get them.