Coco Coir/Miracle Grow Mix Feed

I am a first time grower and all of this has been a huge learning experience for me. I am now to the flower stage and my plants have been growing in miracle grow potting mix. They are indoor and I monitor the PH and RH very closely. I have added Coco Coir to the top of the soil mix so they are miracle grow with about two inches of Coco Coir on top. Do I still need to feed the coco and if so how often do I feed them and what are the best products to use?
Thank you so much!!
I need all the help I can get!

Top dressing extra soil media for more roots? Since it's coco I'd water in some cal- mag not nitrate based. Or top dress with dolomite lime. Otherwise continue your fertilizer schedule if all else looks fine.
But you're not doing that yet?
How many weeks flowering at 12/12?

The coco didn’t really do anything, coco has no nutrients. Pictures would help, is there an issue with the plant? Top dressing with more fresh soil would be a better idea than coco if you’re trying to feed. We need more info and a pic or two to help.

It depends on what type of miracle grow soil you're using. Some has slow release fertilizer that's supposed to be good for 6 months. Read the instructions.

This thread has some great information.