DO NOT dose hydrogen peroxide!! Find the source of the excess nutrients and deal with it accordingly (don't overfeed, make sure you're keeping a stable w/c schedule etc) keeping algaes at bay is easiest dealt with if you have a good way to export nutrients. The most common nutrient export obviously being water changes. If you have the space, I would reccomend setting up a refugium and placing some live rock/chaeto in it to help reduce those nutrients. Good luck !