DI water Purification

[mysis]

Hi Anthony, i have a couple of questions about Deionizing units, and since you use these units yourself, i thought i better ask you.

OK, basically i have been read and researching these and i just have a few quick questions, i'll just make sure i understand it correctly.

Resins in the DI units are called "anion", and they remove negitively charged ions from the water, and "cation" which removes positively charged ions. those 2 types of resins make the basis of a Di unit. Correct?

Right my first question is, Any contaminanty such as pesticides, that are (neutrally chraged), will not be removed. Is that true?

Also i have learnt that the units should never be used to full capacity, since they could begin to release some of the contaminants they have removed back into the water. Is that true?


Thanks
Dean

 

[Anthony Calfo]

resins vary on what they will remove and if they will release matter (many kinds and qualities of resin)...

but yes, they will not extra weak or neutral charged elements as I understand it... and they generally don't leach much either once full (some do... most do not)

You really have to look closely at the exact specs of a specific resin to answer these questions properly, mate.

 

[mysis]

But due to the fact that DI units are 100% water efficient, they are still a better choice compare to RO/DI, also you said on RC that the resins can last a very long time, but i have conflicting information from a book called "The Complete Book Of The MARINE AQUARIUM" by Vincent B. Hargreaves", his book states that resins need to be continually replaced or recharged, with strong acid.

So i am kind of confused

 

[Anthony Calfo]

it depends on the resin... they run the gamut in quality... just like RO membranes run the gamut in quality.

it's interesting that even Kent mentions in their thick annual catalogue that DI produces higher quality water... and they sell Di as well as RO units.

 

[mysis]

Well, sound like DI would be a better choice, I haven't seen any at all in australia, as RO/DI, is the preferd method by pretty much everyone here In W.A for some strange reason, unless it is just the enitial set up cost that scares them away? But you would think due to the water chortages we are having in Australia, LFS would be pussing to get these units in and sell them to people, i think i'll pop down to the LFS and ask.
Oh yes and also while i am here, many people from RC are sad you and the other experts left, we have learnt a new forum site is in the pipeline and well, everyone, is hoping such a thing happens, and there will be much support if such a site is formed.
Thanks