Stems tall = stretching for light caused by not having enough light
stems flimsy = caused by the stretching
Solution: use popsicle sticks and a twist tie or piece of string to make a brace, when first planting seeds only fill your container halfway with soil so if this happens you can add more soil around the main stem in the container to shorten the stem coming out of the soil thus making the plant less top heavy, also run a decent fan at all times because the breeze against your plants will help to strengthen the main stem.
Fans = keeps stagnate air from your grow space and provides fresh co2 for your plants, sturdys the stem.
Light schedule = sprout stage 24 on 0 off
Week 2-4 veg stage 18 on 6 off
rest of growth flowering 12 on 12 off
Exhausting your space is necessity for getting rid of smells that could potentially lure thieves or snitches