Here is an informative article by Dr Lam on the health benefits of fulvic acid. While the article lacks references, I think it is still a pretty good summary.
It is claimed that the best fulvic acid comes from NZ, extracted from ancient Southland peat and sold under the brand, Nucell. I agree.
I recommend adding a dessert spoon to a couple of teaspoons of this into a drink bottle and drink it in 2-3 lots over the day.
I use this when doing long training rides, but adding 4 heaped teaspoons of Energiser to sustain me for the duration. This replaces the need for GMO gels and electrolytes.