Well bummer. Dosing with invertebrates can be tricky. My anemone is my canary in a coal mine. If it looks unhappy, I wait. I generally have always erred on the side of caution with dosing, because I have many other inverts to care for. In a tank with only plants, you can go nuts and push the envelope. Your plants can get everything they need from fish food, if you feed liberally, but you end up with more phosphate than is needed. So I add CO2, nitrate and fish food takes care of phosphate.
Good luck with your project and keep us informed.