Hydrogen peroxide

[mantis]

I'd only recommend 3% or 6% for use in the aquarium.
Outside in a bucket or something you don't need to be so careful as there's no fish/shrimp/snails that could get squirted accidentally.

My crypts are solidly rooted in the tank so no way to remove them without kicking up all the tropica substrate, think I'll go with the 6% stuff, cheers.

Just to makes sure I don't kill all my fish, I put it in a syringe with no dilution and squirt it directly onto affected leaves inside the tank? To be honest this will be a last resort as hopefully I seem to have most of it under control, just a bit stubborn hair algae left on the slow growers I think.

[Gingerlove05]

Just to makes sure I don't kill all my fish, I put it in a syringe with no dilution and squirt it directly onto affected leaves inside the tank? To be honest this will be a last resort as hopefully I seem to have most of it under control, just a bit stubborn hair algae left on the slow growers I think.

Yep
The reaction in water is really quick, the algae will discolour. As long as you don’t squirt it directly on your fish/livestock you will be fine
I’ve done it out of water as well but with the leaves still wet, it makes a satisfying fizzing sound as the reaction occurs, just make sure you dont leave them out of water too long or it starts to bleach/kill the leaves. But that’s only out of the water