I never put nutes in the 5.5 ph soil but on the bag it says it already has slow release nutes. I have grown in the same soil before no real problems just that my autoflower plants that were supposed to grow to about 2 feet grew to 6-8 inches. And the main reason I got new soil and transplanted the big plant and another is because the bigger plant had some major problems, as you can see in this pic it was turning yellow and had the bottom leaves burning
which I think is most likely a ph problem/nute lockout/salt buildup, the other ones are smaller no problems yet but they seem to be getting slightly more yellow as they grow. Im gonna see how this transplant goes and maybe try flushing the other ones then adding some baking soda. Thanks for your help