So you credit your success against dino's to hydrogen peroxide and UVS then.
How big is your system and what UVS are you using? The 40w AquaUV would be good for me I think, but the dimensions are horribly long (38" x 4" x 2.5")... The AquaUV 57w dimensions are more doable though (20" x 4" x 2.5"), so I'd probably go for that. Maybe overkill but that seems to be the way to go with UVS if you're actually going for the kill.
I will let the FM Ultra Algae X take it's course, if dinos come back I will probably run a UVS. These things are expensive though
