don't use it.
those algae fixes will cause havok in your tank
they can harm your biofilter,
plus the decomposition mentioned above,
and even tho they say that they won't hurt fish the fact is any chemical disolved in the water increases the osmotic pressure on the fish and it will stress them out
and ultimately the original cause of the algae bloom hasn't been addressed and it will eventually return
the best algae fix is frequent large water changes, some manual removal (i.e. scraping picking leaves, turning the gravel near the surface) and a good dose of patience- it usually takes a few weeks or a little more
also looking at your photo period to be sure u're not overdoing it there
if you dose fertalizers stop for a week or two, then move back into then at a lower level
also if you have high light and not enough Co2 for the plants to use it up that can be a source of algae blooms
and remember patience patience

algae can be frustrating just have faith in yourself so you don't go crazy
cheers-k