Vitamin/Hormone booster, and yes...I like it for sure. I notice a difference a lot on my Sour Bubble. I have one Sour Bubble plant that was cloned a week prior to a couple other, and it has now surpassed both the other SB that I was feeding MaxiGrow and the VH booster. Until dansbuds told me about it, V+B was growing the plants WAY too slow. 2ml per gal of the hormone booster mixed with 1.2-1.4 EC RO mix is proving to be MUCH better! Without the hormone booster your plants will look healthy, but lack vigor in veg. I am hoping all of my strains like it as much as the Sour Bubble for veg, and 3 other strains that I started feeding the same mix yesterday. I switched 2 Sour Bubbles from MaxiGrow to V+B with hormone booster, because they were not stretching as much as I would like. my Sour Bubble mom receives NO hormone booster, it is getting too tall. I might give Air-layering a try to split the mom up into a few smaller plants... Anyways, anyone using RO version for veg should use that VH booster, unless you need slow veggers. V+B works ok for veg, will keep plants healthy, but no vigor. I need vigor. I have been using tat PUSH spray too,not sure how much that is helping. Spraying 2 times per week. I will update how my other strains do in Veg with the RO version with VH booster...I know how they all do without it, good but slow.