I used Agent Green and my phosphate level is the same
There are a few reasons that the phosphate levels won’t change after dosing Agent Green:
1.) There is insufficient calcium in the water column: This is common mostly in freshwater aquariums. To raise calcium levels (which will also raise pH), add one handful of crushed seashells or oyster shells per 25 gallons. This will buffer the system with enough calcium to enjoy the benefits of Agent Green.
2.) Levels that appear not to change can also be attributed to mature marine and reef systems that are holding phosphate inside of rock and other places it can be held out of the water column. If this is the case, then phosphate is simply being leached back into the water column to replace the removed phosphate as it naturally buffers. Continued use will eventually rid phosphate not only from the water column, but from all absorbed areas as well. This ability makes Agent Green the fastest and most reliable phosphate remover available by far.