tiny hole n problems bringing ph down

Too early for calmag 5.5 ph water Add more soil to the top Your coco is giving you the wrong ph transfer.

at this age I'm more than sure it's nothing, but having problems with your ph will cause all sorts of issues so make sure you keep that within the optimal range to ensure this young seedling gets off to a good start.

Calmag increases the pH ... and at this point in the little one's life, I don't think you need to be adding it... if you buffered your coco with it, that's fine (and, from what I understand, necessary) but don't go adding more! You're going to have a lot of problems if you can't get that pH down to 5.8 or so... What are you using to reduce the pH... whatever it is, use more of it! Good luck (and btw, can't see what hole you're talking about and it would be the least of my concerns at the moment)