suggestion for new plant indoor

hi! i'm cultiving a new plant indoor , i recently transplanted it in a bigger Vase. Considering i use a lamp mh 250w (with an all mix soil) and i don't want (like in the past) the plant grow too in height , just to see even with the LST, just the the higher parts to receive the right amount of light, how much the plant should be growing and be tall (considering the lamp isn't too strong)? thank you

You can grow it as tall as you want really, but it will grow 1.5-2x size once u switch to flower, so don't grow your plant all the way to the light and then switch, cause you won't have any room. If you are using a tent I recommend a scrog net, it helps a ton on keeping everything the same height https://www.amazon.com/Grow-tent-flexible-trellis-pack/dp/B07DJS94BD If you aren't using a tent to hook the net on, I would recommend just some plastic coated wires like https://www.homedepot.com/p/Vigoro-50-ft-Heavy-Duty-Coated-Wire-T025BVG/203894420

If its just one plant with a 250w light, you might consider side lighting it.

AgentPothead said it well. You have to account for the stretch and plants vary with regards to how much they stretch. I am currently growing an unknown strain, I switched to 12/12 when they were around 20 inches and they didn't stop stretching until they were all around 50 inches. Luckily I had that much height to work with. From my experience, sativas tend to stretch more than indicas. It always helps immensely when you know the strain you are growing because the breeders can typically tell you roughly what the stretch will be.

Thank you!!