Mycorrhizae are THE wonder ingredient in any grow and should be compulsory!
Have been growing for 35+ years and discovered mycorrhizae as an experiment 3 years ago and now can't believe I ever grew without their addition to my soil, the results are outstanding and real - extra health and much less feeding is needed, my plants have never been better!
The mycorrhizae (fungus) live on the plant roots and in return "pre-digest" nutrients for the plant, making the nutrients more easily absorbed.
Definitely use the Synergy, it is worth every cent and the benefits are real!
Hope this helps, Organoman.