My favorite is phosphate rx. This stuff is amazing. Just place drops into my skimmer every few weeks when phosphates start rising. I also use rowaphos from time to time but I hate emptying and cleaning reactors.
I used to use Reef Interest PO4x4 anout 4 tablespoons on 650 gallons. I think my swabbie I have on my skimmer got caught up with the phosphate removal so I pulled my GFO reactor off line about a month ago. I feed a few tablespoons of LRS food daily plus the APEX auto feeder dumps pellets daily
Current PO4 .02
I know the swabbie had a lot to be do with increased nutrient export-it cleans the skimmer next 3x day