Why are my bottom leaves yellow?

[Ontario]

What am I missing and does any plant fertilizer work?

[OldManGrower]

Ok my friend. First, being new to this forum, I strongly suggest you read the site that sponsors it. It can answer all of your questions. But to address your particular issue, Your soil appears to be very dry. The yellowing you see often occurs from ph issues which can result from underwatering. Usually it spreads so you need to address it.

[alltatup]

I totally agree with OldMan. If you want to grow mediocre weed, don't study!!! https://www.growweedeasy.com

You absolutely cannot feed Cannabis just anything.