Since I have been using this product I have not had a problem with phosphates in the water. The phosphates were destroying the chlorine and it was causing problems, I now always have a floc block in my skimmer box which seems to have fixed my phosphates problem.
Great product for the price and they last quite a long time. Slow dissolving and also helps with water clarity. I put a small rock on them in the skimmer box to weigh it down on the sock tie end.

Very happy with the results so far.

so far so good,the pool cleared up in two days so that was good thank you