NSW is know to have about .08 PO4 in it. IMO you should switch to making your own water, much cleaner and safer.In srilanka pet shops doesn't sell marine stuff. Used to buy it online but last 2 years I bought all the stuff I need (CaCl2 , MgSO4 and NaHCO3 ) from local drug stores and chemical shops. No brands and not analytical grade stuff.
My tank running smoothly, lot of coralline and lot of coral and sponge growth. Only bad thing I noticed was start getting bit of alga on my LR even I'm running a 8 square feet turf scrubber and 4 feet long sea grass bed.
I use natural sea water and change 1/4 (about 200 gallons) of the total system amount once in every 3 months.
Agreed, 99% of the stuff many major companies sell is snake oil and does nothing. Koral Kolor from Brightwell does nothing at all, used it/wasted money. The additives I buy are kalk, ca, alk, MB7, Iodine or Lugol's, PO4 media and aminos.Feel free to run any particular products by us here. There are a LOT of products with bogus claims, even from the big name suppliers mentioned above.