is amazing stuff. I would encourage anyone who doubts the ability of this stuff to do some research of it yourself. Chemicals will help, but it's temporary at best. You will find this is true in time.
Also, these chemicals are antibiotics. What do they do? They are used to kill bacteria. I could be way off here but wouldn't that include your biological filtration? It has to be impacting it in some way and not for the good. Choose to go that route if you want a quick fix but if you want a permanent fix, rid your tank of the source. Do your water changes, shorten your photoperiod, lessen feedings, rinse frozen food in RO
before feeding, feed better quality food, syphon as much as possible of it from the rocks and sand during water changes, change you light bulbs every 9-12 months and watch your phosphate and nitrates.
We don't even know that the OP has cyano
but even if it's just normal algae, these things will help. Good luck Squado.