Everything is looking good...I like the way its grown compact with short internodal spaces so I've started twisting some clones in solo cups to create more bonsais to make some little shrubs
I keep getting these spots developing on my oldest mother, the MAC. She's probably rootbound, it's been about 4 months since she potted up. I need to keep her in a cup for space, will deficiency get better if I just trim about 50% roots and plant back in a cup with fresh soil?
I would try and invent in a bigger cup. Looks like it wants more phosphorous or some calcium. maybe give it a nice flush if you don't plan on transplanting up in size. Then some fresh feed. could be a buildup in the medium given how small the pot is. If you root prune use clean shears and sterile soil or you might shock it to a early death,
Good Luck!
So far so good, looks great! Wish you fun and good luck with all your bonsai grows, very charming and I look forward to see the next update. Happy growing!