[giftedk]

evening all,
                I got my system from omnipole and they were supposed to send me a refillable di unit, when i received it the di unit was not refillable.I also ordered a big bag of resin they then sent me a refil;lable di unit and told me to keep the other one and use it first. what i want to know is how do i know when the resin is used and its time to start using the refillable one ?.

[AuRavelling79]

Your TDS reading after the DI unit will go up. When it gets to about 010, kick the non-refillable unit into touch!

[baldeagle]

Back in the 1970's, I operated a de-ionising plant for boiler system feed water for BT, we also used it for battery "top-up"; I would use the plant to produce about 1000 gallons every Monday morning.

Then in the '90's I was making de-ionised water for cooling towers in a computer centre for a high street bank.

I seem to remember that in both cases we re-charged the resin by cleaning it with salt water [brine].

Has anyone tried this, or, more to the point, perhaps, why don't any of these de-ionising plants come with such a facility?

Baldeagle in Staffordshire

[steve k]

they do mate...the resin that is regenerated  by saltwater solution is a water softening resin usually found at the first stage of a 5/6 stage RO system. It is a different resin than the finishing resin which cannot be regenerated by saltwater.
Water softening resin beads attract calcium and magnesium from our tap water making it softer before it goes through the sediment and carbon filters then onto the RO and finally through the DI resin used as a polishing filter.
When saltwater is flushed through the water softening resin, the sodium in the salt attracts the magnesium and calcium particles from the resin beads and they are all flushed out through a waste pipe, leaving the resin beads clear of any impurities and ready to do their job again. I flush my resin every 400 litres which takes 10 minutes, then start my water making process which takes 4 hours to produce 450 litres.

[baldeagle]

OK StevieK
Thanks for that!
Baldeagle

[MrT_Beef]

u can get resin off cannabis plants

[steve k]

water must be a naughty word because that is the word I typed ...another meaning is Brine.

[Ian_Giles]

the resin used in the DI that we all use can be regenerated, but it is a pretty specialist operation
Not a DIY thing unfortunately
On one of the other sites I read someones post with details about how to do it, ok in a chemist's lab, but not in your garage

Regards,

Ian