Autos are often overthought.... they are plug and play as they say.
Plant them in a good soil mix upfront and just water for a few weeks.
They hate over feeding and will shutdown / slow / stunt, etc.
That is all I grow .... as I can do perpetuals all year.
18/6
Plant seed into final container size.
EASY watering in beginning..... NOT FULL CONTAINER WORTH.
Plenty of light
No Defol
No Nutes ( if running good soil ) during “ veg “
( soil will feed it plenty on its own )
After say week 5 ( typically) day 35ish ... is when sexing and buds start forming.
If you screwed the pooch at ANYTIME during these first few weeks then it will show when it flowers. It be small / under developed . The “ third wheel “ aspect of autos ( ruderalis ) can run differently than expected....... this gene was supposed to ONLY bring fast finish on cuts.
But ....
It can stunt / runt out / stall / not flower ( have to flip ) / grow differently even from same stock ( lanky vs strong branched ) .... it is a gamble sometimes with the ruderalis as part of the equation...... but with SIMPLE thinking it will produce. It will not be a large yielded in most cases however there are some autos that will grow quite big. I personally have had 4-5 foot autos growing out.
People hate them , but often fail do to “ user errors “ ... nothing else.
Depending on strain , there are DWARFY / LOW RYDER type strains , some form that SINGLE cola shape too . But there are some great breeders out there for better plants ( Mephisto , etc. )
You can’t fuck with them like you do with REGULAR seeds ... just plant and grow.