I doubt that we differ at all AFA kelp effectiveness. It is one of the 2 things bought in bulk, online, the other being neem meal.I build with Kelp meals and amend with extracts as needed......Methods and choices always vary and we each think ours to be better.
Maybe, for the most part. I'll bet we are not that different at all for kelp effectiveness.
Do what works for you, and be happy!
I used exracts/liquids before I got that first 50# bag of meal. Having that much, compared to the 5# bags, led to a lot more using the meal in top dressings and whatnot, where I had used the liquids. The results, to me, were "slightly" better at best, but the ease of use and much lower cost (~$1.30/lb delivered), just morphed into not ordering any more liquids as they ran out and using the meal for everything.
But, kelp is most certainly a "must have", no matter how used.
Wet