[DuTaz]

I have a started my grow 16 days ago ( thats when they went under the lights which are 400 HPS ) i started my plants in this soil " SHAMROCK NATURE'S OWN multi-purpose Compost " and i also add pearlite.
1st Question is : was this the right soil to use ?

2nd Question is : now that my plants are 16 days old is the soil still ok and should i be transplanting them yet to larger pots and if not yet when ?

3rd Question is : ( my bottom leaves are turning Yellow and i have not started to use fertiliser yet ) is now a good time to start puting fertiliser in and if so WHAT KIND, HOW MUCH, AND HOW i know this might sound to be dumb but this is my first time growing

4th Question is : is there a booster for the vegetation stage and if there is what kind do i get and is it really worth it ?

Thanks for that help and if i can think of more question i will add them too lolol

thanks