Seedlings - Grow light questions.

[woody21]

i have set up my propagator with some fluorescent lighting above to stop my seedlings getting leggy. i think i have enough light but how many hours of light per day? at the moment im just putting it on when i get up and off before bed (16-18 hours)

i have no useable windowsills for my seedlings, not enough direct sunlight and far to cold at night. anything in my windows sulks and dies slowly.
so will be putting them into the spare room under a much bigger grow light but only because picked up a bargain lot of indoor growing gear in the local ads earlier this week, impulse buy! it was so cheap i had to!, since then ive been reading up about how to use it all.

how do i acclimatise seedlings to go under a 600w hps grow lamp?
it will be tomato, pepper and melons i have to try first in there.
its a blinding amount of light, even with the light 5 foot above its still mega bright and i think it will shock them. i know from reading that its strong enough to scorch plants if i get the leaves wet while light is on.
its warm and bright, like having a but of australia of my own

i have a few plants in there already (not seedlings), chilli plants have perked up and really love it, tomatoes too have improved and look great for the 1st half of the day but they droop a little in the evening but im unsure why. too much light maybe? or too warm in there? (has extractor and fans, temp it 75-78F)
hoping they settle in and get used to it, but i bet the seedlings would get stressed.

any thoughts, advice or suggestions welcome.

last question, am i nuts? my freinds and family sure think so!

[Two_Sheds]

What spectrum/lux is it?

[woody21]

What spectrum/lux is it?

the flourexcent tubes are blue spectrum for plant growth, not the red fruiting ones.

the hps lamp is a sunmaster hps (high pressure sodium) dual spectrum bulb. however the graph on the box shows only small spike in the blue wavelength and most of its output is up towards the red end of the spectrum.
no lux specs on the box, google tells me 90,000 lumens output for a 600w hps lamp.

[Two_Sheds]

how do i acclimatise seedlings to go under a 600w hps grow lamp?

So you already have the seedlings? Somewhere? And you want to now move them under the lamp?

[redser]

Well for what it's worth this is what I used ... a 5 ft twin 60 watt shop light. Had it suspended from a plank resting either end on chairs. I kept the seedlings/plants a couple of inches (max) below the light. I only had it on for 8 hours a day and they flourished. Remember not to give them too much light, they need to rest. This light is very intense and more than they would get during an average day in our climate. They didn't grow at all under the lights. But did all their growing in the dark. I think that's when the photosynthesis actually happens?? It was amazing to see the growth spurts taking them out each night. You could exhaust them by giving them too much light. So cut your hours down and save on the bill at the same time. I locked mine away in a cupboard. Used it for 2 months (early-February - early April). Since then, with the brighter longer days I've been using windows sills and a cut down blowaway out the back garden. Then bring them in at night. Toms are getting on for 18 inches with 2 trusses and some flowers open. Chillis and peppers all have flower buds.
Can't tell you anything about the hps but it sounds amazingly bright! See if you can shade them a bit? Or else sell it on and stick with cool white flourescents.
Best of luck

[Maccabee]

I think you're nuts to be converting your spare room and spending all that effort and money on equipment to grow chillies

The temps seem fine, certainly not enough to wilt an established tom. And the light should be ok for them too. Maybe they are thirsty by the end of the day? Is the soil dry?

[Aberdeenplotter]

Ordinary fluorescent lamps work well enough. Some exhibition growers use them. Sodium lamps throw out an incredible amount of heat as well as being extremely expensive to run. As soon as your seedlings are big enough, get them outside(in a cold frame or similar) during the day if possible and take them in at night. That way, you will harden them off ready for planting on and give them all the light they need.