I have one patio tomato plant in a ~6 gallon container that is loaded with tomatoes (most are still green at this point). In the beginning, I started feeding with organic fish fertilizer, but growth wasn't great and after researching, I realized that in containers, it's very difficult to be successful organically without further nutrients. So, for the last couple months, I've been using Miracle Grow, and the plant has taken off (very lush, lots of flowers, lots of tomatoes).

I just noticed recently, however, that the newer leaves on the top are starting to get yellow between the veins, similar to the chlorosis on my rhodo.

Any ideas as to what it might be? Do I need to use something else other than MG for heavily producing tomatoes in containers?

Thanks.