When I set up my Earth box and add the media, I add my first top dressing. I leave a clean area where I'm gonna plant, either the seed or the transplant.
This gives the top dressing time to breakdown to be available.
Those look like the little square ones. I think those are a bit deeper than the juniors and the regulars. About four and three quarter inches deeper. There is a distinct possibility you may have to do a top
misting of water. They may have a problem wicking that far up and keeping the top dressing moist enough for bacterial activity and plant usage of the top dressing. With Earth boxes you must be careful about top watering to prevent washing of nutrients down into the reservoir. You can run into problems if that occurs with the reservoir flipping and turning acidic.
With that being as deep as it is, I think it probably will be about 21 days before you'll actually be able to fill the reservoir with
some water. You don't want to fill the reservoir until the girl is ready for it. Depending on the moisture level of when you potted up their box, you can add a limited amount of water probably about 10 days out from Sprout. Probably for this size I would limit it to a Dixie Cup amount of water. All this does is have the wicking areas a bit more and moist so the roots will tend to go toward that area. Hopefully you packed the wicking areas when you potted it up. They need to be relatively firm fill the media in that area.
Take a look at this post. I kinda go over how I top Dress and what I do.
I think I have my girls picked or the next grow. 4x4 is a CBD/THC med grow. Jean-O's Genetics CBD Haze S1 Auto Fem gets a regular Earthbox. SUPER SATIVA CLUB AUTO ELEPHANT gets a regular Earthbox. Autoseeds.com Sweet CBD gets a Jr Earthbox. Twenty 20 Vidamints 50/50cbd gets a Jr Earthbox...
www.autoflower.org