Yes it indeed seems like the Jack is not having the time of her life. It might be a nitrogen toxicity reaction, which usually presents itself as dark green colour. Even if you used a "Light Mix" type of soil, some plants are more delicate if it comes to Ec values which might result in stress or even burns in case if the Veg Feeding is introduced to early, no matter the doses. We would recommend give it few days on water only to see if she improves..