After reading through this thread last week, I started peroxide dosing and lights out. Prior to this, I went through a 3 week treatment using FM's Ultra AlgaeX. I was hopeful after starting with 48 hours lights and the initial 3 doses. My skimmer was pulling all sorts of gunk out. Then, as I brought the lights slowly up to more normal levels, but still only about 6 hours with blue lights and 3 or less with whites, the dinos started to return. The Ultra AlgaeX gets dosed every 2 days and by the 2nd afternoon, my sandbed and rock were starting to coat in dinos.
This week, I've done 3 days of lights out followed by a day with blue lights only for about 4 hours, and now I'm in my 2nd day of another 3 days lights out. I'm hopeful but will know more next week as I bring the lights back up.