Killing Algae On Waterfall Rocks?

[msr0459]

I've had my pondless waterfall up and running since late last year. I now have green rocks on all the water paths. I've read online that hydrogen peroxide applied directly to the rocks (with waterfall off, obviously) will kill the algae fairly quickly.

Can anyone attest to this working? I'm aware there are products I can purchase expressly for this, but since I have so much, I figured peroxide would be way cheaper.

I've already applied a product for the string algae, but it's had no effect on the "green" rocks.

Thanks!

Edit* I just found a thread on using sodium percarbonate on rocks to Kill algae. Easy enough to sprinkle directly on the horizontal rocks, but I also have a lot of green, vertical surfaces. Can this stuff be mixed with water and applied with a sprayer? I was thinking that may dilute and/or diminish the end result?

 

[Hound Heaven]

It was wonderfully warm a few days ago and since the algae was beginning to get thick in a few spots, I unplugged the pump and then squirted peroxide around. Drying it in the sun really helps too.