i prefer excel to h2o2 to get rid of algae. i just turn off filter/powerheads, and dose the full dose into algaed areas and turn the filter on after 5 min. works great for the occasional tuft off bba i get on ancientish anubias leaves.
but should your shrimp eat the algae? mine go to town on stringy algae.
Eheim Pimp #296
Canon Pimp #67