"Mandarin333" wrote in message ...
What are the drawbacks of using mixed bed DI resins?

You probably can't recharge them. Typically, a heavy metal remover such as
Kent's toxic metal sponge can be recharged with muriatic acid whereas an
organic scavenger like seachem's hypersorb can be recharged with bleach. Once
you mix them, you can't recharge them anymore and will just have to eat the
cost of replacement whenever they get exhausted.

Yes, this is a known fact rather than a hidden drawback... but ok.

Also, KENT makes a unit with two separate resin beds: anion/kation
and these you can recharge if you want. If you really want to deal
with acids and bases at home... Yes, if you have no small kids
running around it could be feasible, but otherwise... questionable.

KENT makes also a DI unit which works with tap water WITHOUT a RO
stage: this way you have NO WATER WASTED if you care so much about it.

In your last resort, when you really use them a lot, you can do
mixed resin separation yourself, recharge them, and mix them back.
I have found an article somewhere on the net describing the process
but do not remember where was it exactly.

Personally, I just fill a clean trashcan with tapwater then dechlor and heat it
to temp. I filter it with a high grade carbon and phosphate remover along with
toxic metal sponge and hypersorb in a cannister filter. That way half the water
doesn't go down the drain as with an RO unit and I can recharge my resins
unlike with a mixed bed DI unit.

What phosphate remover & heavy metal sponge do you use?