Grow lights switching from metal halide to HPS

[F1rechicken]

Hi if you had plants under 18 hours of light with a Metal Halide bulb and switch to an High Pressure Sodium bulb,but keep it at 18 hours on how will this affect the growth of the plants?

 

[Hosebomber]

It would cause stretching and elongation of the plant.

 

[F1rechicken]

what if the plants are already showing signs of sex but are still kinda short....would switching the bulb without changing the hours of light help them get taller?

 

[JJ Bones]

Why do you want them taller? You want short stout bushes. Not long, stretchy plants.

Anytime you grow indoors I encourage smaller sized plants for success. If you do go the big plant route you will need plenty of supplemental lighting to make it worth-while.

 

[F1rechicken]

they been on 18 hours of light with a metal halide for about 3 months and they are only about 2 feet tall....they are rather bushy I just wanted them to get bigger....if I switch bulbs and the amount of time to 12 hours I know they will start the flowering cycle,I was just hoping to get more out of them by them getting taller at this stage.

 

[DrOfDank]

When you switch to HPS & 12/12, they'll go what's known as 'the stretch', where, depending on the strain, will continue to grow up to double or triple the size. Judging by your description, you have an Indica that will grow to up to double in size, IMHO.

 

[LivenBurn]

u probably need to re-pot already-- ur rootbound sounds like... hope u got the vert space indoors...