From the National List of Allowed and Prohibited Substances:
(j) As plant or soil amendments.
(1) Aquatic plant extracts (other than hydrolyzed)—Extraction process is limited to the use of
potassium hydroxide or sodium hydroxide; solvent amount used…
Thanks Sherwood and Lizette! You've given us some great suggestions and I appreciate your thoughfulness. One small thing that I do to search for Extension information is to put site:edu in the search phrase. You'll get educational institutions other…