> On Tue, 20 Jun 1995, Peter Cole wrote:
>
> > The problem with drinking water filters is that they use salt
> > to soften the water - hardly ideal for plants! However, carbon
> > filters are available which are suitable. I use a Britax
> etc
>
> Thanks. So I should look out for a carbon filter purifier. Durham is
> quite soft, but Leeds (with exactly the same geology) is quite hard
> (Yorkshire Water artificially harden the water!).
Yeah, now they're privatised they've probably got shares in the
water softener industry (cynic? me? :)
I've just cut open a filter, for curiosity's sake, and I'm
quite surprised - there's not much carbon in there, but a lot of
what I take to be polymer beads - I guess about 25:75. These
beads are .5 - 1 mm and white in a used cartridge, so I poked a
hole in an unused one, and these are yellowy and clear.
So I take it that this is some sort of osmotic process...
What I'm wondering now, is if there is any way to rejuvenate the
used beads, and save having to bulk buy cartridges with monotonous
regularity. Anyone know how this process works, and if it can be
reversed to clean the beads?
I remember someone mentioned cartridges costing $10 in the US -
these are 2.50 UKlb here (umm, $4-ish?). Conceivably it might be
cost-effective to import them from Marstons? It would depend on
postage costs I guess...
Happy growing,
Peter
> From Loyd.Wix@URCGB.SPRINT.COM
>
> Regarding water purifiers/filters, I am not sure how
> effective a carbon filter will be at removing inorganic
> materials from tap water. I use rain water until supplies
> run out in prolonged periods of dry weather - then I resort
> to acidifieing tap water with citric acid. I still dont like
> this solution as I am concerned about long term salt build
> up in the compost.