Ok, let's not go crazy. Don't you think "crash" is a little overly dramatic? I mean I brixed yesterday at 10. So more like falling out of a window on the first floor. My 10 could go to what 8? 7?
I'm just trying to get this plant to the finish line with a lesser bug issue. I have added the bone meal to my weekly top dressing but it'll be at least a couple of weeks before any of that breaks down enough to be useful and the plant is already half way through flower.
Start with a tea then. Use molasses but at a heavier rate, more like a feed.
Go 1 tbsp per gallon of water, add in a full solo of EWC, some kelp or something like that, and some crushed up bone meal. Maybe 2 tablespoons, or if you have some high P guano try that. Any high P mineral that is powdered.
Brew the molasses and other ammendments for 24 hours in a warm room and then toss in the EWC for another 18-24 hours and see what that does.
If you can get it in when they are only half-way dried down so it homogenizes easily throughout the pot thats even better.
Toss some powdered High P crumble in too if you like. That way you get a one time sugar boost and a huge influx of new microbes.
Most will die as the pot restabilizes the population but the corpses will be filled with P from living in the tea.
Thats pretty much the tea I give every grow right at flip. I use more minerals than just that, I add some glacial rock dust and a smidge of SRP.
You know that O2 is good because you are watering properly, Ca is good as per the refractometer, and you have microbes, so it's carbon or P.
Put both in with molasses and a P source, and if you have kelp it's always a good additive. See what happens.
If you are just trying to reach the finish line at any cost, a weekly tea is far better than just sugar water. It's the fastest way to get P in. One good tea could do it.
The only down side to tea feeds is that you may get tip burn if it's too strong.
I would start with that knowing that calcium is already good.
Wash in a top dressing with it.