With Vibrant, you add it weekly amount based on tank size.
More frequent water changes, focused on dying algae areas and not larger water changes. For instance, I would add after weekend water change, then would do a Tuesday or Wednesday night water change after work, then usual weekend water change, add Vibrant, supplemental Tues/Wed water change... repeat, repeat... Some will say take out rocks and scrub with maybe toothbrush, rinse with RO or saltwater and place back in tank, but most of my rock has coral encrusted so I didn't do that. With hair algae get in there with your hands to pull out manually to help speed its eradication. There is a lot of good online info, some will say Vibrant doesn't work, some will say Vibrant works fast, my experience like most: it took a couple of weeks to make any impact, so seemed like things getting even worse, but from start to finish for me and my tank was 3 months. It didn't get bad overnight, it didn't go away overnight, so even though that felt maddening to me - for reef tank it was probably all for the best... Now I'm back to "normal" but scared to introduce nuisance algae again with any new corals esp as it was a long 3 months. I've got additional dip types arriving today, but they'll sit unused until I see something I just can't have. Whatever it is will be dipped my new dip method: 1) peroxide on plug/rock or plug/rock removal, 2) iodine type dip and 3) new to me dip type (coming, natural, watch BSR video). Good luck to you!