I disagree. I'm currently on my 3rd bottle so I've given it enough time to perform it's alleged magic.
I already introduced plenty of LR with purple, pink, red, orange coraline on it and it's been steadily deminishing despite good levels and regular doses of Purple Up.
I've since quit using the Purple Up and I'm now dosing two part Ionic Calcium and I'm now just beginning to see some spots on my tank walls after a month.
I've also got enough lighting according to most opinions.
I'm not saying it doesn't work but it hasn't shown me enough to keep using it at this point any longer.