Building a DI system

[erik]

Hello all,
I would like to add a DI system to my RO unit and I'm having trouble
finding the anion and cation resins.
I'll be building the cartridges myself so I'm looking for just the
resins. I've found lots of refill cartridges that I'm sure I could
open up to get at the contents but I'm thinking it's cheaper if I can
find a source for just the resins.

TIA
Erik

[Pszemol]

"erik" > wrote in message ...
> I would like to add a DI system to my RO unit and I'm having trouble
> finding the anion and cation resins.
> I'll be building the cartridges myself so I'm looking for just the
> resins. I've found lots of refill cartridges that I'm sure I could
> open up to get at the contents but I'm thinking it's cheaper if I can
> find a source for just the resins.

1. Using just one anion and one kation resin in a chain is not
a very good idea. I am sure your father will explain why...
Use mixed bed resins instead. Or, at least use mixed bed
resin at the end of the chain to polish water and equalize pH.

2. If you still want anion/kation resin refills go to the store called
http://www.championlighting.com and check out their R/O
Cartidges & Membranes section. You will find anion and kation
resin refills in 64oz packages for $19.99 each...
This product is branded by KENT - contact them if you want
other sources... Maybe KENT will know some retailer in your area.

[Gary V. Deutschmann, Sr.]

Hi Erik

Find a Kent Marine dealer, Kent sells both resins in bulk sizes.

TTUL
Gary

[erik]

Why not use an anion bed followed by a cation bed (or vice versa)?
What problems would I be facing?
I thought it would be better to have seperate beds so that recharging
is easier.

I'm afraid my father and I don't speak very often.... :o(




On Fri, 6 Aug 2004 10:38:23 -0500, "Pszemol" >
wrote:

>"erik" > wrote in message ...
>> I would like to add a DI system to my RO unit and I'm having trouble
>> finding the anion and cation resins.
>> I'll be building the cartridges myself so I'm looking for just the
>> resins. I've found lots of refill cartridges that I'm sure I could
>> open up to get at the contents but I'm thinking it's cheaper if I can
>> find a source for just the resins.
>
>1. Using just one anion and one kation resin in a chain is not
>a very good idea. I am sure your father will explain why...
>Use mixed bed resins instead. Or, at least use mixed bed
>resin at the end of the chain to polish water and equalize pH.
>
>2. If you still want anion/kation resin refills go to the store called
>http://www.championlighting.com and check out their R/O
>Cartidges & Membranes section. You will find anion and kation
>resin refills in 64oz packages for $19.99 each...
>This product is branded by KENT - contact them if you want
>other sources... Maybe KENT will know some retailer in your area.

[Charles Spitzer]

there's no problem with that. as a matter of fact, if you follow gary d's
great info on how to recharge a twp filter, that's what is recommended. it
has to be split anyway when you recharge it because you use different
chemicals for each.

regards,
charlie
cave creek, az

"erik" > wrote in message
...
> Why not use an anion bed followed by a cation bed (or vice versa)?
> What problems would I be facing?
> I thought it would be better to have seperate beds so that recharging
> is easier.
>
> I'm afraid my father and I don't speak very often.... :o(
>
>
>
>
> On Fri, 6 Aug 2004 10:38:23 -0500, "Pszemol" >
> wrote:
>
> >"erik" > wrote in message
...
> >> I would like to add a DI system to my RO unit and I'm having trouble
> >> finding the anion and cation resins.
> >> I'll be building the cartridges myself so I'm looking for just the
> >> resins. I've found lots of refill cartridges that I'm sure I could
> >> open up to get at the contents but I'm thinking it's cheaper if I can
> >> find a source for just the resins.
> >
> >1. Using just one anion and one kation resin in a chain is not
> >a very good idea. I am sure your father will explain why...
> >Use mixed bed resins instead. Or, at least use mixed bed
> >resin at the end of the chain to polish water and equalize pH.
> >
> >2. If you still want anion/kation resin refills go to the store called
> >http://www.championlighting.com and check out their R/O
> >Cartidges & Membranes section. You will find anion and kation
> >resin refills in 64oz packages for $19.99 each...
> >This product is branded by KENT - contact them if you want
> >other sources... Maybe KENT will know some retailer in your area.
>

[Pszemol]

"erik" > wrote in message ...
> Why not use an anion bed followed by a cation bed (or vice versa)?
> What problems would I be facing?
> I thought it would be better to have seperate beds so that recharging
> is easier.

It is better to have separated beds for recharging, of course.

But it is NOT better for the performance of water filtering process.
I am not an expert in this field but I have read in reliable sources
that cation and anion bed generate ionic imbalance affecting
the performance of each other. Simply said - when you have water
with NaCl dissolved and you remove cation you do not "remove"
it - you replace it with H+ ion. Doing this you increase acidity of
water and lowering performance of the following resin bed. Similar
effect you can observe when you "remove" anion Cl- you do not
remove it, you replace it with OH- ion. To minimalize effects, in big
water purification plants they install SEVERAL cation/anion
exchange stations in chains to create very clean water. In a smaller
scale, "mixed bed" resins are such anion/cation stations chains
in a one case: they just work better, more effective when mixed
than if separated and connected in a chain.

As a disclaimer I repeat I am not an expert and I wrote above
from my weakening memory ;-) so I might be wrong in details.
But mixed bed resin works much better than two separated
anion and cation beds connected in a chain - that is a fact.

A practical solution in our hobby would be to use 3 containers:
first two for separated anion and cation resins - these will
take the dirty water and not last long (but you can easily
recharge them) and thirds filled with mixed bed resin for
water polishing - this one will last much longer in such setup.
For very small scale, like my 30 gallon tank, one mixed bed
resin last for more than a year, so I do not consider it an issue
and I do not plan to recharge resins until I will get a bigger tank.