Interesting thread, I've never used vibrant specificly but my experience in general with bacteria type products is that you should always start with a much lower dose than manufacturers recommendations to see how your tank reacts. Usually if it's a weekly recommendation I try about an eighth and...
www.reef2reef.com
work threads are such data gold.
on a good note: Vibrant is the best valonia control ever found in the hobby, so if you are expecting valonia in the uglies then use it. if not, what you should do is not dose vibrant AND not wreck your tank. expect the uglies but handle them in person with rocks removed, set out on the counter vs always seeing your reefing problems as a water/param adjust and test issue
reinstate manual dirty gardening, digging, burning where creative. outside the tank, make your rock stacks accessible is the best trick you'll ever do.
expect to be removing rocks, not altering your water params, so you can clean them off (and in the exposed spots siphon up mess on the sandbed) and set rocks back in the tank cleaned, manually guided.
you get to back off in two years, price of a dry start.
for sure you can forego all this, and you can see how untampered uglies is faring out for folks as well. direct access willingness and planning is what you want, not a purchase or a doser. its a resolve, not a $