Maybe it would be a good idea to find out why your tank had an algae issue before investing more time and effort in Glosso. Without knowing the cause you run the risk of having the same problem again.
Len
After reading numerous posts regarding trimming hairgrass "like a lawn," I cut mine. The result was brown ends that never grew and a severe algae infestation only in the hairgrass. The grass did grow new shoots but anything that was cut did not grow anymore and became infested with stringy algae.
I didn't have any algae issues prior to this but a good point none the less Len.