Nice plants! First stop thinking you need to provide this for that phase of growth and that for this phase. The idea is to put what is needed in the soil and then just water your plants. Soluble nutrients are handy but once you begin to use them you cannot really go back to adding dry soil amendments. There’s a reason people who grow with them tend to stay water only.
Fish bone meal is a great soil amendment but it’s only part of the story. I add it into my mix at every recycle. Best thing to do is to add it to the soil about a month before there are plants growing in it but a top dressing with a few other inputs is an alternative. You’ll need an active soil mix in order for bone meal or whatever amendments you add in to break down and become available. That means you will need a form of compost (ie worm castings) to provide the soil with active microbes that decompose organic matter for absorption.
Fish bone meal in and of itself will not make your buds bigger; lighting/wattage is what governs the yield. P value of 1-25-0 seems way too high for an organic input. Otherwise I would suggest trying a simple top dressing of fish bone meal, kelp, and ewc although your plants don’t seem to need much. The buds are still developing and plants are quite healthy so why not just keep on doing what you are doing for this run? You can amend and recycle the soil after next harvest properly for the next run and aquire some better amendments in the meantime. For finishing these buds I would brew up a guano tea; my advice.
Here’s a simple recipe:
6-10 pellets of guano (or 1 cup EWC)
1 tsp molasses or pure maple syrup
1-3 gal clean water
(Optional) 1 tblspn liquid fish
(Optional) 3 tsp kelp meal
Bubble for 24-36 hrs and serve