Welcome to APC! That Tetra product is a new one for me. Just reading the website description of it says it may be dropping the phosphate level too low for plants to thrive, and dropping the nitrate level too low for plants to thrive. The description reads to me like a scam, but I won't say it is one. In any case, if the plant growth is slowed by that stuff, algae will begin to colonize the tank. Algae loves aquariums where the plants struggle to grow.