Ok so second nuking was Monday. I hit all the majanos I could see (at the time, I see more today that I didn't hit). I think I had about a 60-75% success rate. Those majanos that are facing upwards are much easier to nail than the sideways ones. I did miss a large patch in the back forty (at least I think I did) and one rock I actually took out of the tank and nuked as almost all of the majanos on it were sticking out the side of the rock (and frankly the rock was small and easier to take out). I nuked a couple of aiptasia which I have a 100% success rate for so far. I thought I tested a mushroom but sadly I can't remember where the damned thing was, it was a single mushroom and I can't find any singles anywhere nor any leftover bits so we can maybe call that one a tentative success. I also hit a few odd shaped polyps that are like a cross between a short tentacled majano and a rust colored zoanthid. Easy peasy, they're gonzo and so is the algae they were mixed in with on one of my powerhead brackets
I'm not sure I'd be so worried about doing a water change right afterwards, although I'm sure its a good idea. I turkey basted up the precipitate after each "treatment". The waterchange (20%) did perk up the tank though, everything is looking fabulous a few days later.
I'm also happy to report that nothing croaked that wasn't supposed to during the treatment. There were a couple of close calls as you can see the sodium hydroxide in the water column sort of like you can see a hypersaline solution in regular water or lower salinity (kind of looks like a heat wave under water) and you really need to give that a quick stir so it precipitates before it hits anything. At one point I thought it landed on one of my acans but it precipitated at the last second and all was ok. Its definitely soemthing you need to be careful with or you could end up with dead spots on any corals that are underneath treatment areas.