Artificial Light intensity

Suncoast

Suncoast

Last season was my first year growing peppers.   i am south of Tampa so my main issues were the heat and white flies.  On the whole, I was pretty pleased with the results but I found that certain species needed to be placed in a "sweet spot" for sun exposure to do well.  Unfortunately a few got pretty crispy before I figured this out.
 
Oddly enough, several members here said that, with the exception of their Rocotos, they left all their plants in full sun all summer and never had a problem.  I find this doubtful based on my results.  
 
This year I tried an experiment.  I started way too many seedlings of way too many types about 6 weeks ago under artificial light in my workshop.  The light source is a 4 bulb 2 foot unit rated for 10,000 Lumens.  It has the capacity to only have two bulbs lit which would give 5,000 Lumens.  I have had it on full for 16 hours a day about 14 inches above the plants for the past six weeks and have observed the following:
 
The Chinense and Frutescans are thriving.  Deep green and no leaf issues. 
 
The Annums and the Baccatums seem to be yellowing and even showing minor sunburn.  
 
I moved the second two groups to the periphery of the light a few days ago.  Too soon to see any improvement.
 
What I need is some input from you experienced growers as to how you handle the intensity of the artificial light.   I am actually planning a large scale permanent grow in the workroom and want to have the best chance to have the plants do well
 
I live in southern California and it gets really hot during the summer. This last year I put my plants in a spot where they got full sun til 1:30pm and the rest was shade. They did really well. Consider a shade cloth  it's an added expense but your plants would really benefit from it.
 
From my experience on indoor grows there is no way you have too much light with florescents 14 inches above the plants..That's the distance I run my MH's at. And only get occassional burn on the tips..Let's see some pics.I bet it is a watering issue..But that is just a wild guess. Not seeing.
 
This is today at 4pm.
I only grow under 40% shadecloth or shade after 1pm.
And they really thrive.
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Sent from my HUAWEI VNS-L31 using Tapatalk
 
Second question on the same topic.
 
A few of the plants I recently started have begun to produce blooms while still quite small.  What causes this?  Too much light or not enough?
 
What measures did you take to solve your first problem? Or has it somehow resolved itself? Any reason for not posting pictures, which would help us figure out what the issue may have been, like another poster requested?

If you are still running that fluorescent light 14 inches above your plants, your problem is not excessive light, period.
 
Just pull off the white flowers to promote growth. And again you don't have a too much light issue. Except for heat I don't think their is such a thing as too much light. 
 
Sorry for the lag in replying and posting pics.  The flu has had me on maintenance mode for almost two weeks.
 
Here are several pics of my setup taken today.  As you can see...I am still getting some yellow leaves and leaf drop in addition to way too many small plant starting to flower.  
 
Any suggestions would be much appreciated
 
 
 

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To be clear, the larger setup is two 4 bulb 2 foot unit rated for 20,000 Lumens each.  It has the capacity to only have two bulbs lit which would give 10,000 Lumens each. 
 
I could really use some input here if anyone has any thoughts.  Some, not all, of the plants are losing their lower leaves and starting to yellow
 
I'd second MtCtChilehead's guess about it being a watering issue.

Is there a fan directed at the plants that I'm not seeing?

I ask because those pictures suggest your setup does not encourage a whole lot of transpiration in your plants.

Very low light intensity, judging by how far those lights are above your plants. No air circulation (if you don't have a fan). If the temperature in your garage is closer to your lows (60°-65°) than your highs, that will also be working against you. Very high humidity in your area, which I'm guessing is similarly high in a garage. All of the above will mean slower rates of transpiration, which will make your soil more of a liability if it holds a lot of water. And it looks a lot like a peat-based mix from your pictures - those tend to hold lots of water.

So basically, a soil that holds a lot of water and growing conditions that don't encourage a ton of moisture loss through the leaves can create over watering issues even if you think you're being careful.

Can you describe how you've been watering them?

Also.. just out of curiosity, when do you plan to put them outside? Sunshine and warm temperatures would probably solve your problems, and it looks like your lows are already 60°-65° or so?

EDIT: I also wonder if you might be seeing your plants shedding leaves that are just not getting enough light. Those fluorescents are very high, especially in relation to the lowermost leaves.. which also happen to be shaded by the upper leaves. It's not unusual for plants to drop leaves that are no longer getting enough light to be productive.
 
That is actually the input I was looking for.  There is between 8 and 12 inches between the bulbs and the tops of the plants.  With the intensity of the light as described, what distance should they be?  they are easily adjustable.  
 
Temp in the room varies from 70 to 78
 
Humidity is a constant 50%
 
I have a ceiling fan on in the room but I do have fans I can focus directly on them.  
 
I have been watering them every three days.  That seems to be before any wilt can happen but my moisture probe is reading semi dry
 
This is my first year with the grow lights indoors.  I actually planned on trying several in the room for the full season.  That is the reason that i am trying to dial this in a bit.  The rest will be going outside in the next week or so.  
 
Do you know the type of fluorescent light you are using? Are they T5's? High output (HO) T5's? T8's?

Those all have different light intensities, which will determine how high they should be above the plants. Regardless which type you have, though, 8 to 12 inches is way too high.

Light intensity goes down (a lot) as distance increases when you are using artificial light. This is one reason artificial light is harder to work with than natural sunlight. With your lights 8 to 12 inches away, your plants are probably growing in the equivalent of "light shade" or even "heavy shade". No good for a plant that needs "full sun." I know it may look like they're getting plenty of bright light - but I guarantee the intensity is too low for good plant growth.

The number one thing I would recommend is to lower those lights until they are 2 to 4 inches from the tops of your plants. I would do this incrementally over a period of about a week to make the transition gentler.

I also recommend a fan (gently) blowing towards your plants. I cannot stress enough the importance of air movement when growing indoors.

Your humidity and temperature both sound good.

I still suspect a watering issue in addition to the light issue though. I personally don't put a lot of stock in moisture meters when using soilless mixes, and watering every 3 days sounds excessive for your soil, light levels, temperature, and humidity.

Do your pots feel noticeably lighter before you water than they do after you water? Weight is a good way to judge when watering is needed, but it takes a bit of practice to get a feel for it.

Have you let your plants go until they wilted? If you haven't, that is another way to determine how often you should be watering (although it is somewhat stressful for the plants). See how long it takes them to just start to wilt, then the next time around, water them a day sooner. This could be useful for you to determine right now how often to water, since an occasional wilt isn't going to kill a pepper plant. However, since moisture needs change for potted plants as they grow, your best bet long-term is to get a feel for the weight of wet vs. dry and to base your watering frequency on that.

Two other things to pay attention to if you plan to grow plants to maturity indoors: what are you doing for fertilization, and what are you doing to prevent salts from accumulating in your soil (both from fertilizer and from your water source itself, if you aren't watering with distilled water)?
 
The smaller setup is aT5 4 bulb 2 foot unit rated for 10,000 Lumens.  It has the capacity to only have two bulbs lit which would give 5,000 Lumens.  The larger setup is two 4 foot fixtures that are 4 bulb each with exactly twice the output of the smaller setup each.
 
I do check the weight of the pots prior to watering.  They always seem lighter.  I have waited an extra day or two a couple of times and have seen noticable wilt on some of the plants
 
I generally use a dilute fish emulsion as fertilizer.  The plants usually get up potted at least three times during the season.  The pots in the pics are their first up pot from 12 oz Dixie cups.
 
I did not realize the importance of a fan. I set one up this evening
 
I personally don't use organic fertilizers when I am growing in containers with a soilless potting mix. I am aware that some people prefer them, but container growing often does not support the soil food web necessary to process organic fertilizers into forms plants can use. Switching to a synthetic fertilizer with a ratio close to 3-1-2 may help you. Using a very diluted dose each time you water tends to be more effective than the "high dose, rarely" that the packaging usually recommends.

It sounds like watering may not be the issue, so I would suspect that lack of light is your main problem.
 
Suncoast said:
One question I forgot to ask...how many hours of light per day is optimum?
Click to expand...
 
When my old light timers broke in 2015 I left my CFL's on 24/7 for the entire grow. Stuff turned out good. 
 
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But those are not as bright as a T5 HO.
 
This year I'm doing 16 on 8 off on my high output T5's. For seedlings I'm keeping them 10" above the tops, to avoid scorching them. I still have the grow mats plugged in since half the trays haven't sprouted yet, so I don't want to cook the plants. Soil temps are staying at 92-96F with that setup and they don't seem to be getting leggy at all. 
 
When they get a bit bigger (many are developing 1st true leaves now), and I'm done waiting for any lingering sprouts to pop, I'll shut off the grow mats and slowly move them closer until they're 4-6" away. (Or whatever the soil temp tells me is "good", I want to keep it somewhere around 90F.)
 
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