ro/di color changing ?

[charles6299]

i have a kent marine 4 stage ro/di unit.......i have it installed now for 4 weeks and the di cartridge is turning reddish half way......
question #1...is it still good when the color is half way ?
question#2...i have EXTREMELY hard water, will putting in a water softener lengthen the life of the di cartridge ?
........we had Culligan water come out today....we tested 18 grains of hardness....youngstown city water is 7 grains....i am hoping by putting in the water softener is going to be ok for the fishies and coral.........

[Steven Pro]

Usually the DI cartridge is good until the entire thing changes color, but sometimes the two resins in the cartridge get shaken enough to seperate. When this happens, you will see two distinct colors split in half.

A water softener will help the RO membrane, which in turn will likely prolong the life of the DI resin.

[Unresistible Blue]

Steven is right on. Sounds like you need to get a tds meter!

[BubbaWPB]

sometimes the two resins in the cartridge get shaken enough to seperate. When this happens, you will see two distinct colors split in half.

OOOOHHHHH! So *THAT'S* why it happens ... I've been wondering why, when I replace the DI resin, it changes half way suddenly, then stops.... I bet it's the pressure motor thingy I have attached that shakes the whole unit... good thing the unit came with a TDS meter... I knew the resin wasn't bad yet.

[Unresistible Blue]

The separation of mixed bed resins is due in part to the aggitation of the water passing through the cartridge - but probably more importantly is how the resins were packed in the cartridge originally, and how long they have been in use.

Over time, the resin beads will shrink while in use. If the resin in not packed tightly in the cartridge, the anion and cation beads (only one of which contanes the color-indicating dye), will separate, and you'll only see the color change in half of the cartridge.

If you are using bulk resin and a refillable cartridge, pack the resin tightly!