Dark shiny leaves, Clawing towards the ends. Is this a sign of N toxicity?

Hey growmie, yeah, that’s early nitrogen toxicity, dark shiny leaves clawing down is a giveaway. Happy Frog already has nutrients, and adding Gaia 4-4-4 on top can push it over the edge for young plants. Best move now is to stop adding anything with N and just water with pH’d water (6.2–6.5). Let them burn through what’s already in the soil. Once they lighten up or stretch a bit, you can bring in a lighter top dress, ideally lower N and more P/K (like a 2-8-4). You caught it in time, they’ll bounce back just fine. ps what Hashy said makes sense as well so maybe a combination of things...