Need Help with High Phosphates

[Myka]

Over-skimming is fairly difficult (unless you're trying haha). Generally, that is not something you need to worry about. Purigen is fine, I wouldn't say it is better or worse than carbon, it's just another option.

12 grams of the Fluval is about 15 mL (1 tbsp) or so? That is definitely on the cautious side, but that's good. I'm not convinced your phosphate is 1 ppm though, that's really high. You could add another 12 grams every second day or so. What does the Fluval stuff say is "full dose"? I use about 125 mL per 50 gallons of BRS normal capacity GFO, but that is quite aggressive.