I had extremely high phosphate of 4.0> in a newly set up 1500 ltrs marine system and as it was not stocked with any livestock and coming to the end of the nitrogen cycle I used this to get the reading down to 0.20 in a week.
I use every day to keep the phosphate down just one capfuls a day, very good product, you know when the phosphate is being lowered by the amount of cloud that is produced in the tank