Aquatic Plants Digest V1 #86

> Poly Filter by PolyBio Marine will most certainly remove virtually
>all benefitial trace elements from a planted tank.  It's a fantastic
>filter for removing heavy metals and other wonderful things from your
>water.  PolyBio Marine makes excellent water purification filters and
>the fish store certainly didn't mislead you.  However, I doubt that it
>is good idea to use this filter, in-line, on a planted tank.  If you are
>relying only on the trace elements found in your tap water, the poly
>filter is most likely removing all "trace" of them (pardon the pun).
>This type of filter is great for pre-filtering your tank water before a
>water change though.  I'm considering using one of these filters as a
>prefilter for my RO/DI unit.  I'm hoping it will help extend the life of
>the Deionization filter.

Good advice; I am only using it short term on a tank I just set up, to
remove what I believe to be excess iron.