the first person 2 tell me was my friend he owns 3 hydroshops, i know hes trustworthy we grew up 2gether but i had been using root excelulator for so long i didnt want 2 switch even tho root 66 was more than half the price so i kept using RE for another grow, i started asking every hydroshop owner or worker when i stoped by them and they all told me the exact same thing that tecnaflora sent root excelulator in 2 a lab and had it copyed they sell it as root 66, almost every1 i have talked 2 who used 2 use RE now use root 66 because its so much cheaper!! there are a few that wont switch just because of the name, i tell every1 i can because i know how much RE costs if its a small grow its not 2 bad but if you have a couple 100 gallon res's your running threw a 100 dollar bottle real fast