I am thinking of using river sand on a new Discus tank, can anyone suggest a good "available" option in the Sydney area...

It would need to be such that it didnt affect the chemistry of the water, as well as being able to foot some grass type plants (with the aid of root tabs and C02 for the plants well being and successful growth).

Colour is not that important, just as long as it is not to dark, and not too fine...

thx in advance.