Kombucha mold help

Hi,

This is my first post in this forum so let me introduce myself. I'm spaingt and I live in Benidorm (Spain, of course).

This is also the first time I have made Kombucha tea and I need help with a possible mold problem in my first batch.

The thing is, since about the second or third day, three black dotted lines apeared arround the top edge of the tea and at first I thougt it was mold, but I am now in the 12th day and they don't seem to have spead much or look that much like mold to me anymore. Anyway, I wondered if someone with more experience could help me find out if they are really mold or if they are just normal formations that acure on the newly forming "mushroom".

Here's a few photos (sorry about the quality of some of them):

I hope someone can help me.

Greetings from Spain.