Hey friend !
I always buffer my coco with cal mag and using it from starting the seedlings in small doses of 0,5-1 ml/lt . That’s because coco coir actually needs cal mag itself , using all of it and not enough staying for the plant.
Also , I always go with ph 5,8-6 max .
You do good with watering and keep in mind that you can not easy overwater coco so it’s better watering more times than less. I never let coco dry at all ✌️✌️
Good luck there 🍀