phosphate sponges, water purifyer

Gail Bowker wrote:
>>I'm looking for a bit of advice about my tank and water supply.
>>2.      My aquarium bloke sold me a phosphate sponge and told me to use
>>that in the tank because of the high level of phosphate in our water
>>supply.  I did so, but would like to remove it and replace it with a normal
>>fluval sponge when the plants/gravel/laterite/lights are in place.  Are
>>these sponges the only way to remove phosphates, and are they a bad idea?
>>3.      Same aquarium bloke would like me to buy a water purifyer unit (a
>>cheap one, not an RO unit).  I'm note sure about this though.  After it
>>filters the water, you have to add a pH adjuster and Electroright (no
>>ingredient list on the side of the bottles).
>>A government water analysis gave the following reading of our tap water:

>Nitrates 1ppm
>>Silicates 10 ppm
>>phosphates 1 ppm

Bill Brady, Maryland USA replied:
>The level of phosphate in your water supply needs to be dealt with. The
>nitrates will also become a problem if you use straight tapwater to
>replenish evaporation.
>You can get phosphate removal resins that are very effective.
>I would also suggest that you put Nitrex or Spiroex in the bottom chamber,
>both will eventually act as a de-nitrator.
>If the water purifier unit suggested is the Tap Water Purifier (TWP) by
>Aquarium Pharaceuticals, I do reccommend it for making top off water. It
>produces pure water which is what you need. In this case you would not add
>anything to it.
>If you have unacceptable levels of hardness, the TWP water can be mixed
>with in when you do partial water changes.

Bill,  Thanks for your suggestions.  What are these phosphate removal
resins?  I am using  Phosorb at the moment.  It consists of some granules
in a bag that is placed in a chamber of the Fluval.   Is this the same
thing as you are talking about?

And the aquarium shop did not know the name of the denitrators you
mentioned.  He in fact said he had heard that denitrators did not do a lot.
I'm a bit confused now.

The Water Purifier is the TWP that you recommend, but it results in
deionised water doesn't it?  Then why wouldn't it be necessary to replace
the trace elements and fix the pH before adding it to the aquarium in top
up water?  BTW the tap water here is very soft about 40ppm.