I've used Coco-wet for years. A small bottle of it lasts forever. It's organic.
I'm not sure if I would buy LK nowadays. I know they stripped it from what it used to be concentration wise. Ferti-organics sells Fulvic/Humic powder that is pretty good and cheap. I've used the Soluble Fulvic from them.
Ferti-Organic has dedicated itself entirely to the organic agriculture. We have developed a complete line of natural raw materials and insect repellents for farmers, blenders, formulators and agriculture companies. We are committed to the organic sustainable agriculture and to those who just...
www.ferti-organic.com
Customhydronutes sells small sizes of their stuff.
Edit: looks like Ferti will send you samples if you email them.