That is nute burn my friend. What soil are they in? One of the first rules of farming is to read, learn and study, before you plan and act. Second rule, never add anything to your medium that you are completly unfamiliar with. Never used seaweed extract. But since seaweed is I am sure high in salinity , she is likely nute burned. In order to help you out, we will need to know what is in your medium, the PH of the water, the soil and the run off water. what other nutes are alrady in the medium right out of the bag. And how much seaweed extract you gave her. At this point, it does not seem to devestating, probably a good flush with some ph'd water and maybe a better mix of the soil you have. But again misdiagnosis happens here I am no Jorge Cavantes. But if you provide the info I suggested, either I or someone I can steer you too or towards your thead will be able to better assist. Good Luck!
