Hi! Really great info in that video. Spot on. The only thing I heard (and it's not much) that needs a correction would be regarding "lowering the temp to treat ich". The actual myth is with raising the temp. This apparently works on fresh water ich but not saltwater ich. Your spot on with that. Just thought I would add that one little tid bit. Great video again!
I will comment that lowering temp can be useful to reduce the metabolic demands on the fish and to increase available oxygen in the water. Lowering SG helps with both as well. This is important if a fish has a lot of parasites/worms in the gills and is essentially being suffocated to death.