Just posting a warning. Be very careful with any Product using Lanthanum Chloride. MUST filter through a filter micron 10 or 5 even better sock. Products like these work but at a risk. The resulting particles that form need to be filtered out or you will have loss of fish. Not just tangs but angles and other fish as well.

I like this product because I can easily adjust the number of drops to reach the phosphate level I want. The fluconase did not work for me and neither did gfo although both products work for most it seems. With gfo it is not easy to place the proper amount that you need to reach the level you desire. It only worked a little for me anyway. Fluconase probably kills certain kinds of hair algae but not the one I have so I am not knocking either of the products that didn't work for me, just saying. But Phosphate Rx does work for me!

Great product but experiment with low dose until you’re comfortable with effectiveness. Used 60 drops on a 250g and lowered phosphate (according to Hanna checker) from 0.72 to 0.12. As Gary notes, skimmer kicks in to high gear and I use a 10 micron filter pad to catch the precipitate. Also, as many have noted and written on the warning label, can affect yellow tangs. Well I don’t have any yellows, but my Kole and Powder Brown do scratch themselves against the substrate and park themselves in front of a power head for a bit. They’re fine after the initial cloudiness clears.