Instead, remove as much of the Cyanobacteria as you can by hand, with a siphon or even by taking the plant out (if it is a Java moss for instance) and washing it, gently rubbing it, under the faucet.

You wish to remove the causes of these pests. If you are adding a fertilizer, especially one with ammonia, stop using it. You might fiddle with your light - extend the hours per day which may give the plants more energy to compete with the algae. A fancy phosphate absorbing sponge in your filter can be used too. Phosphates are a key limiting factor.

The biggest cause of these things - especially if there is Cyanobacteria in there - is the increase in nitrogen products. Ease up on fertilization and change more water more times.

Some fish will eat hair algae. Certainly young Chinese algae eaters can be used if you don't mind euthanizing them later. Black mollies may help if you don't feed them too many flakes - which are much less work than the algae eating. I may try some Ameca splendens or American flag fish in such a tank too. If you get American flags from a shop, quarantine them and give them an anti-parasite treatment.

I just recommended an article here on better algae eaters than the Chinese algae eater. That FINS site probably has it.

The APD index is at FINS. Search at http://fins.actwin.com/ and you will get more ideas. But do a water change first. :)