light distance from seedlings

auntavis

auntavis

Member
My last grow, which was my first grow, I think I had my light too far from my seedlings. I used a 250 HPS all the thru the grow and will this time as well. Last grow my seedlings got to leggy and shot up to fast, so I lowered the lights this time to about 3 feet above the seedlings. This time around they are in plugs which are in trays of water. Should I move the lights closer or is 3 ft a safe distance to not damage the seedlings? One seed has poked thru the plug (with seed still attached) and the other is threatening...any input on distance?
 
8

85jetta

Member
i have lemon skunk seedlings under a 400 watt hps an its only about 18 inches above the seedlings an they seems to be doing just fine and they are very compact as well, i dont think you will have any problems puting a 250 watt about that far if not a little closer. Id just play around with them a little bit to see what works better and what doesnt, just keep a close eye on them to make sure that if something goes wrong you can fix the problem before its too late.
 
Snafu1236

Snafu1236

Well-Known Member
dude, put a thermomemter at the canopy. maintain a 78F temperature, no more than 22" away, and this is ideal. you may want to gradually inch closer, start from 28" and move to 22" over a 3 day period. At 22", move your 250 W down as close as you can with monitoring and maintaing a cool, wind driven 78F. even better if youre using an air-cooled hood.

pull light away if you notice pale tops/chlorophyll bleaching.
 
auntavis

auntavis

Member
Thx for the input...the thermometer is a good idea. If mine weren't so young I'd feel more comfortable lowering the light, but with the seed still attached I'm hesitant.
 
jawbrodt

jawbrodt

Well-Known Member
^No, it won't hurt them. Think about them being outside....the sun is brighter than the majority of peoples' setups, and seedlings love it. Your enemy, is the heat produced. If you can keep that under control, you can run that light 9-10", no problem. If you wanna play it safe, wait 3-4 days after sprouting, then put them under full light. Keep it around 16" til then, and you won't have to worry about a thing. I use flouros, and keep them within 1 1/2", right from the beginning. They love it.
 
auntavis

auntavis

Member
good to know...I have one that is sprouting leaves already, and one that still hasn't cracked it seed shell. It looks pitiful laying limp with a seed on the end of a root. It broke thru good and went on its side. Hopefully it'll do the damn thing. I lowered the lights today to about 14-16" so it should perk up if its going to. I'm afraid to mess with it too much.
 
Shmulster

Shmulster

Active Member
hey auntavis i used the chart that frmrboi put up and i can tell you first hand that if you use it they actually dont stretch at all (a week and a half after germing i even put it closer). 250HPS dosent get that hot if you have proper ventilation so the closer the better (ofcourse to a point where if you put your hand above the plant and its uncomfortable you pull it back a abit). hope this helped :)
 
Kiboko

Kiboko

Well-Known Member
Exactly what I was looking for, many thanks... truth be told, the chart is more useful than a graph imo.
 
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