I disagree with Done. First of all excess phosphate is most certainly a major factor in black beard algae growth and PhosPure adds nothing to the system it only removes excess phosphate, emphasis on the word Excess. For whatever reason be it the fish load, plant choice, substrate or any combination of these and other factors, the phosphate production in this tank exceeds the plants ability to remove it therefore intervention is required in this case. I’m not saying that this is The cure for Black beard algae all I’m saying is before you start dipping your plants in bleach or hydrogen peroxide rule out excess phosphate.
How does a product designate what is needed and what is excess?
Seachem claims that PhosGuard can limit PO4 to 0.2 ppm. Many people far exceed that with their doses, in fact, target dosing using the EI method is stated as 1-2 ppm.
I've had a couple BBA outbreaks and gotten rid of them without changing my phosphate input levels one bit. More often than not fluctuating CO2 is the issue.