The number one reason to use external spot treat testing with peroxide before we bother adjusting nutrients is because the only way to evaluate a nutrient adjustment in tank is to see if the change prevents growback--not if it removes the built-in algae.
If we have cyano, siphon remove all of it, detailed hours work, then apply your peroxide to the cleaned tank. The 2016 method is about work first, peroxide second, collect more wins than earlier years.
When we apply peroxide to cleaned surfaces and detritus free tanks, not wrecked ones, that's doing differently than the masses and it's a bigger win on your algae because the hard work first step was your cost for having grown it and challenged yourself.
Algae targets respond better to peroxide when algae biomass has been hand-removed or cleaned by the keeper, before the peroxide addition. This is about the win not hoping a chemical does all the work for us. Algae tufts left in tank are self supporting mini biomes and by removing the mass you gain an upper hand, nutrient controls are for prevention not removal of invaded conditions.
***expect new mini invasions from alternate communities when you clean a set of rocks and have them in a reef not covered by coralline and coral flesh.*** the original allowance of takeover began the halt for coralline and coral deposition, because we decided to catch up means a cycle of work will be needed or use the cleaned rock as base rock under rocks covered in coralline and coral. Take no action with peroxide before a test rock has shown total compliance first. Total growback control must be attained on your test rocks first before you know what to do with the whole tank.
http://www.nano-reef.com/topic/374651-can-a-cycle-be-complete-in-two-weeks/#entry5354480
vegasgundog from friends at nr.com using a little peroxide water to blast some gha as part of early tank cycling. its responding well enough to non scraping that topical only treatments are fine, its not very set in and this appears to be working just fine.