RO Gel filter discolouration?

[Anonymous]

Hi

My RO unit which has only been running for around 10 weeks now has a clear compartment filled with a gel type substance as the last (of 4) filtration stages. The filter is only used for evap topoffs as I access my own sea water and thus dont mix RO and salt. Usage is thus minimal. Originally the 'gel' was a deep purple, near black colour. I notice that at both ends of the canister the gel has started to turn orange. Is this normal and what does it indicate? My LFS is unable to provide an answer.

Sooo excited, have to tell someone! My tank is filling up with occupants, got a pile of different shrimps for it last night and put 4 tiny occilarus clowns in my fuge (for now) last week. Also got a big emperor that dominates and put all my LR into the main tank! Starting to look absolutely wonderful! (Sorry, just had to let someone else that understands know! :lol: :lol:

 

[Anonymous]

The gel is actually a deionization resin (DI resin) that remove additional ions that your RO did not remove. Your is a "color changing" DI resin, and it is often to have the color change to give you an unusual stratification. However, in your case, I suspect that the saltwater leak back to the DI chamber, making it to lost capacity in the upper (output) end. Make sure there is an air gap between the topoff output and your saltwater to elimitate this problem.

 

[Anonymous]

Thanks for the prompt reply!
The outflow was in the sump and in contact with salt water for some time... now I have finished the automation process setup it is above the water (actually the outflow from my Kalkstirrer) there is now a non return valve between the RO unit and the kalkstirrer as well. From your response, I assume the colouration will stop growing under these circumstances (?)

 

[Anonymous]

>...From your response, I assume the colouration will stop growing under these circumstances (?)

Yes.