ive taken the time to link you to the first results of a google search.
First of all, I would like to thank you for such a great question relating to the article:
this is the guy who wrote it: Rich Hamilton, has been in the hydroponics industry for more than 20 years, working originally as a general manager in a hydroponics retail outlet before becoming an account manager at Century Growsystems
. He enjoys working on a daily basis with shop owners, manufacturers, distributors, and end users to develop premium products.
if you need articles from scientific journals ill look them up for you.