New Grower When???

[Kman1965]

My plants are 19 days old today. At what point should I switch from MH to HPS? Thanks in advance for your help.

 

[Jr kron]

I switch around the time I switch to bloom nutes. I switch to bloom nutes at the end of the stretch. There's a thread around here that states exactly when to switch but I can't find it.

 

[seraphim19]

Jr Kron is spot on.

You want to keep her under the MH until week 5-6. When you notice the vertical growth slow down or stop its time to change lights and nutrients

 

[Kman1965]

I switch around the time I switch to bloom nutes. I switch to bloom nutes at the end of the stretch. There's a thread around here that states exactly when to switch but I can't find it.

Thanks for your help....I appreciate it

 

[Kman1965]

Jr Kron is spot on.

You want to keep her under the MH until week 5-6. When you notice the vertical growth slow down or stop its time to change lights and nutrients

Thank you for taking the time.

 

[SAVAGE]

when the plant stops growing them switch to bloom nutes and hps light

 

[low_and_slow]

I'm a bit more broad brush with my recommendations, but I'd say that so long as you won't stunt or burn a seedling, HPS is fine all the way through the plant's life cycle. I've grown photos and autos from seed under LED, HPS, CFL, etc. Never noticed a difference other than how many HPS/MH bulbs I burn out by handling them excessively ;-)