Unfortunately we don’t sell any item specifically formulated to create nutrient jelly. I would recommend trying Thrive Alive B1 Green, I do not know proper amounts or what heating may do to it. It is a great general purpose fertilizer and is derived from three different types of kelp. Something else you could try, use solely the jelly to propagate seeds, and add the nutrients to your watering regime. A daily watering schedule consisting of feed-water-feed-water or feed-water-feed with the “feed” day being a weak nutrient solution and the “water” day using solely water would be much easier than trying to find a product to add to your jelly.
Find Thrive Alive B1 Here: https://www.planetnatural.com/product/thrive-alive-b-1-green/
Good Luck!