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RE: Phosphate control

Steve Benz was asking about "total cost of ownership" issues with various
schemes of removing phosphates from his phosphate laden tap water. Steve,
provided that you have the space and the patience, I think that you might
have disovered your _own_ solution:

  [[ And no, there's really no mistaking that reading.  One of my tanks
     has low algae and fearsome plant growth -- 3 weeks after the last
     water change, it has almost as little phosphate as a bottle of
     distilled water I bought and tested.  I changed the water in it,
     now it has some phosphates.  I filtered some tapwater through
     PhosGuard and then tested that water, it came out fairly phosphate
     free.  I dropped KH2PO4 into the test-tube, it turned blue...
     There's no problem with the testkit here.  ]]

I don't know where you live, it's not clear from your signature line, but if
you pay for your water by the gallon, the use of a R/O water filtration unit
can be expensive as well. If your locality experiences water shortages, as
many areas in North America do, it is also kind of "ecollogically unsound"
to waste so much water.

You have discovered that quickly growing plants can suck nutrients from the
water column like a sponge - if you have the space and the light, you could
take advantage of this fact and use a plant like Azolla to pre-treat your
water. Just setup several open holding tanks in an area which gets plenty of
light, fill with tap water and add a handfull of Azolla. Let the growing
Azolla strip the nutrients out of the water. Once you determine that the
phosphate levels have fallen to a level you can live with, use that water
for your water changes.

James Purchase