lights on/off per 24 hours??

RomanX · March 9, 2016

Between last year and now, it seems I forgot how many hours per day to have the floureascent lights on for my tomato seedlings. I figurre I've got about three days until I MUST turn them on, so HELP. PLEASE!!

pmcgrady · March 9, 2016

Mine are on 12 to 14 hours, seedlings are looking nice.

Cole_Robbie · March 9, 2016

I think consensus is 12-16. I usually run mine 24 when I need the heat. I will shut them off on afternoons for a few hours if things get too hot. As soon as they go into six-packs, they go into the greenhouse and get whatever hours the sun shines.

TightenUp · March 9, 2016

16 on 8 off

kath · March 9, 2016

Quote:

Originally Posted by TightenUp

16 on 8 off

This is what I shoot for- they go off when I go to sleep and go back on when I wake up.

heirloomtomaguy · March 9, 2016

I give em 17 hours on 7 hours off. Why? Because i set the timers that way long ago and have yet to change it.

Merediana · March 10, 2016

Uhm, whenever I make it out of bed till I go to sleep again

It worked great for my peppers and eggplants and it now seems to work for the tomatoes, too.
Last week I haven't had much sleep because I had to do so much work for university and after around 16h the seedling were folding their leafs up. Seems like they couldn't handle more light...

jessleigh · March 10, 2016

Ive run em 24 hours a day and had no problems. I always forget to turn em back on whrn i shutem off..... and havent bought a timer out of lazinessmormforgetfulness, im notmsure which haha

bower · March 10, 2016

From what I've read, the usual recommendation is to let the poor dears get their 8 hours sleep.

I like my eight hours too, so it's easy to follow that without a timer. Gives them more of a day/night difference in temperature too, which afaik is healthy for them.
Sharon Rossy had some strange results last year we thought may be caused by lights on more than 16 hours, there's a thread here somewhere... I don't know if others have had similar issues. HTG I guess you're proof that 17 is also not a problem.

Also, if you really need the heat as Cole does, of course you have to leave em on.

One thing I've noticed by trying different light regimens, I got the earliest flowering dates under natural light conditions, that is spring day lengths closer to 12 than 16 hours.

PureHarvest · March 10, 2016

I've done 24 hrs of light and the plants did ok
But then I think about the fact that plants respirate during dark. Respiration takes the energy that was made by light /photosynthesis during the day and sends the energy/products throughout the plants at night.
I only did the 24 hr day a long time ago and now wonder if I limited my plants potential even though they looked ok

Worth1 · March 10, 2016

I dropped mine back to 12 or 13 on and they did great.
Worth

kurt · March 10, 2016

It is all about the oxygen/Co2 exchange for the plants photosynthesis requirements.Different plants vary in their needs at particular growing stages.Maters are/can be bred for seasonal differences.Alaskans have a good record for producing large plants/produce with 24hr daylight sequences but shorter warmth periods.12hr on 12 hour off is a norm for me.Plenty of variables to consider.Cannabis growers use different lighting cycles for optimal bud formation.

http://scienceline.ucsb.edu/getkey.php?key=2860

http://scienceline.ucsb.edu/getkey.php?key=3375

brownrexx · March 10, 2016

14 hours on for mine.

BigVanVader · March 10, 2016

Ya I find anywhere from 12 to 18 hours works great.

AlittleSalt · March 11, 2016

I have two rooms where they get different amounts of light.

One is where I sleep with very heavy curtains, so whenever I get up I plug in the florescent lights until 10pm.

The other room has lots of natural light first thing in the morning and florescent lights when I plug them in until 10pm.

So...yeah...the perfect 16/8 thing

March 9, 2016	#1
RomanX Tomatovillian™ Join Date: Jan 2015 Location: North Carolina Posts: 119	lights on/off per 24 hours?? Between last year and now, it seems I forgot how many hours per day to have the floureascent lights on for my tomato seedlings. I figurre I've got about three days until I MUST turn them on, so HELP. PLEASE!!

March 9, 2016	#4
TightenUp Tomatovillian™ Join Date: Mar 2011 Location: Jersey Posts: 1,183	16 on 8 off __________________

March 9, 2016	#6
heirloomtomaguy Tomatovillian™ Join Date: May 2013 Location: glendora ca Posts: 2,560	I give em 17 hours on 7 hours off. Why? Because i set the timers that way long ago and have yet to change it. __________________ “Enter by the narrow gate; for wide is the gate and broad is the way that leads to destruction, and there are many who go in by it. Because narrow is the gate and difficult is the way which leads to life, and there are few who find it."

March 10, 2016	#11
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	I dropped mine back to 12 or 13 on and they did great. Worth Last edited by Worth1; March 11, 2016 at 10:53 AM. Reason: Drooped

March 10, 2016	#12
kurt Tomatovillian™ Join Date: Oct 2011 Location: Homestead,Everglades City Fl. Posts: 2,500	It is all about the oxygen/Co2 exchange for the plants photosynthesis requirements.Different plants vary in their needs at particular growing stages.Maters are/can be bred for seasonal differences.Alaskans have a good record for producing large plants/produce with 24hr daylight sequences but shorter warmth periods.12hr on 12 hour off is a norm for me.Plenty of variables to consider.Cannabis growers use different lighting cycles for optimal bud formation. http://scienceline.ucsb.edu/getkey.php?key=2860 http://scienceline.ucsb.edu/getkey.php?key=3375 __________________ KURT Last edited by kurt; March 10, 2016 at 11:33 PM.

March 9, 2016	#2
pmcgrady Tomatovillian™ Join Date: Feb 2015 Location: Central Illinois Posts: 1,836	Mine are on 12 to 14 hours, seedlings are looking nice.

March 9, 2016	#3
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	I think consensus is 12-16. I usually run mine 24 when I need the heat. I will shut them off on afternoons for a few hours if things get too hot. As soon as they go into six-packs, they go into the greenhouse and get whatever hours the sun shines.

March 10, 2016	#7
Merediana Tomatovillian™ Join Date: Feb 2016 Location: germany Posts: 190	Uhm, whenever I make it out of bed till I go to sleep again It worked great for my peppers and eggplants and it now seems to work for the tomatoes, too. Last week I haven't had much sleep because I had to do so much work for university and after around 16h the seedling were folding their leafs up. Seems like they couldn't handle more light...

March 10, 2016	#8
jessleigh Tomatovillian™ Join Date: Feb 2016 Location: san martin, ca Posts: 9	Ive run em 24 hours a day and had no problems. I always forget to turn em back on whrn i shutem off..... and havent bought a timer out of lazinessmormforgetfulness, im notmsure which haha

March 10, 2016	#9
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	From what I've read, the usual recommendation is to let the poor dears get their 8 hours sleep. I like my eight hours too, so it's easy to follow that without a timer. Gives them more of a day/night difference in temperature too, which afaik is healthy for them. Sharon Rossy had some strange results last year we thought may be caused by lights on more than 16 hours, there's a thread here somewhere... I don't know if others have had similar issues. HTG I guess you're proof that 17 is also not a problem. Also, if you really need the heat as Cole does, of course you have to leave em on. One thing I've noticed by trying different light regimens, I got the earliest flowering dates under natural light conditions, that is spring day lengths closer to 12 than 16 hours.

March 10, 2016	#10
PureHarvest Tomatovillian™ Join Date: Mar 2014 Location: Mid-Atlantic right on the line of Zone 7a and 7b Posts: 1,369	I've done 24 hrs of light and the plants did ok But then I think about the fact that plants respirate during dark. Respiration takes the energy that was made by light /photosynthesis during the day and sends the energy/products throughout the plants at night. I only did the 24 hr day a long time ago and now wonder if I limited my plants potential even though they looked ok

March 10, 2016	#13
brownrexx Tomatovillian™ Join Date: Feb 2016 Location: Southeastern PA Posts: 1,420	14 hours on for mine.

March 10, 2016	#14
BigVanVader Tomatovillian™ Join Date: Mar 2014 Location: Greenville, South Carolina Posts: 3,099	Ya I find anywhere from 12 to 18 hours works great.

March 11, 2016	#15
AlittleSalt BANNED FOR LIFE Join Date: May 2014 Posts: 13,333	I have two rooms where they get different amounts of light. One is where I sleep with very heavy curtains, so whenever I get up I plug in the florescent lights until 10pm. The other room has lots of natural light first thing in the morning and florescent lights when I plug them in until 10pm. So...yeah...the perfect 16/8 thing