Hey mate.

Those plants are looking beautiful.

I my self and a few other local growers completely discourage miracle grow. Some people like it, some people hate it.

There's much better soils out there then what you see on the tv.

Have you taken a pH reading of the soil? What ratio of NPK are they getting now to correct said nutrition issue?

Curious to see if the problem lies within the soil.

Good luck mate and will check back!