ive got a couple of plants under a hps at the moment, im planning to flower this weekend so there ready before i go on holiday... due to the LST undertaken my plants arent very tall... would it increase yield or decrease yield if i hung the lights about 4 ft from the plants in the hope that they would stretch a bit before i started flowering to increase stem length and therefore possible bud sites, then droped them back down after a week or so...

i some times stretch in the first week of 12/12. so when they have stretched the buds arrnt as close together. but thats just me, it seems to help, i think,
but 4 foot is too much. my lites are normally 1foot, from the top of the plants, but when i want to str. i just move the lite or plants 1 3/4 foot or 2 foot. for a week. 4 foot is kind of too much. your plants will get leggy and fall over.
what lites are you , wanting to use?.

having longer stems between nodes is not an advantage. You want to have close nodes...so the cola can grow together instead of single buds.

It's always best to keep your light as close as possible while maintaining heat issues and light spread.

Drink!

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"The art of medicine consists of amusing the patient while Nature cures the disease." -Voltaire

having longer stems between nodes is not an advantage. You want to have close nodes...so the cola can grow together instead of single buds.

Well this is debatable...If you live in a high humidity environment, some times with certain strains it is better for alittle stretch to counter mold issue's. The down side of course is that the lower buds are further away from the light..

it mat be so, but in some cases i find it helps, depending, on what style of grow you want.

buzzy.... ill move the plant close then... cheers