Just tested and tank water and GFO reactor water are both at .18. The levels have been coming down steadily since I changed out the reactor media last about 1 week ago. I am using Warner Marine Research PHOSaR HC (High Capacity) .
.18 is extremely high. If you're getting .04 out of your reactor then it's doing its job.
If it is coming out of the rector at .18 then it is probably exhausted. I would use a small amount changed weekly until your phosphate comes down.