trouble is no matter what it is, if you can't be sure of the quality of the water you are getting from the LFS, it could all be a waste of time, could come back if the water is the cause.
Many people find the LFS water is not the greatest, they are generally busy places, changing filters etc can get forgotten.
I wouldn't start with Vibrant yet, try and work out where the issue is coming from, rather than adding something to fix it.
It could just be a new tank thing, to me it looks like diatoms, and maybe the water you are getting has too much silicates in it, if it just blows away and disappears with a turkey baster.
Look to either make your own water or buy distilled water from Walmart and add the salt yourself, see if that calms the diatoms down.
That's what I would do, make sure where you are starting from is not the issue.