When should I see visible mycelium growth?Updated a year ago

The answer will depend on several factors such as type of genetics used for inoculation, quality and strength of genetics, and room temperature.

Spores:

The first two weeks for spores undergo a process known as germination. It will take another week or two to see visible mycelium growth. 

Liquid Culture:

With the right environmental conditions implemented and quality genetics used. Then visible mycelium growth should begin to show up near the injection site in two and half weeks. 

Keep in mind that the injection site is usually in the middle of the growing medium. Mycelium may be growing in the middle but will need some time to reach to the sides of the bag.