Indoor Lights

[MoeCanada]

Hi All,

 

I just bought a new CFL 200 WATTS light for my aquaponics. The growbed is 2.5' x 3' and just wanted to get feedback on how high the light should be from the seedlings. If i keep my hand close to the light it does have heat and burns to touch and also how many hours a day should i leave it on. Thank you for your feedback

[TCLynx]

You want the florescent lights rather close to the plants.  A few inches from the leaves.  How long will depend on how fast you are trying to grow the plants divided by how much you want to save electricity.  Some where between 12 and 20 hours of light per day probably.

[Sylvia Bernstein]

You want to keep that light 3 - 4" from the tops of the platns, and keep them on for 16 - 18 hours a day once they germinate.  Anything less than that and they will get leggy, e.g. stretch out to look for more light.

[John Gelineau]

I use 125 W CFLs on my indoor grow beds. I usually keep them about 6-8 inches away from the plants. Though since i have such a variety of plants in my beds some mornings i wake up and the snow peas and brocoli are touching the lights. They usually get a dehydrated looking "burn" depending on how long they have been toughing. I usually just prune my rapid growers more often because of this. I usually have to angle my lights, base end up ,to get good light to everything because of the distance of the light to the plants. I have also found, depending on the setup, when u go to hang ur lights, hang them in a way that the base is closer to the back side of the bed, dont just center the whole light unit, because this causes shadded areas from the base of the bulb. Check out my videos i have poasted, the basement garden part 1-4, to see what i mean. As far as time on and off, thats up to you. If you can afford it, keeping them on arround 18 hours for there vegatative growth stage is ideal, mine only stay on for 14 hours and do just fine. They dont grow legy because the light is so close they dont feel the need to stretch to find more light. There all nice and compact. If you have anything that flowers you can use a 2700K flowering CFL and decrese the light cycle to induce flowerein and fruiting.

[Paul Van Lare]

My aquabundance is producing mustard spinach, kale, and romaine very well under flourescent lighting.  It seems that the sweet spot is 3"-6" from the bulbs.  Recently I spoke with an orchid grower who uses standard high bay fixtures with cool white T8 tubes from the local hardware store, so a T5 Badboy like the one shown in this picture is just one of the many Flourescent options.  With the 8 lamp fixture shown I noticed a healthy poulation of algae growing in the bottom of my ebb and flow fitting column. This was solved with a piece of cardboard over the hole. Hey Sylvia, when are you going to make an attractive cover to replace my cardboard? Maybe something that matches the system... 

[AJ Grottke]

You want the light as close as possible to the canopy (without burning the plants) while still illuminating your entire growbed.  Note that light diminishes exponetially as it gets farther from the object it is illumintaing. (Beer-Lambert Law)

[Sylvia Bernstein]

Hey Paul.  Just sent your image to our manufacturer...I'll let you know.  The light stand is being announced soon....

[Paul Van Lare]

I agree with AJ.  The justification for sticking to 3" or more is that the plants tend to grow quite rapidly in my Aquabundance and can easily grow 1-2" in 48 hours. So I avoid burning plants when not tending to them daily.

AJ Grottke said:

You want the light as close as possible to the canopy (without burning the plants) while still illuminating your entire growbed.  Note that light diminishes exponetially as it gets farther from the object it is illumintaing. (Beer-Lambert Law)

[Paul Van Lare]

Great!  I'll take three when you get em in.  :-)

Sylvia Bernstein said:

Hey Paul.  Just sent your image to our manufacturer...I'll let you know.  The light stand is being announced soon....

[Diane Reilly]

LED lighting are widely being utilized for distinct outside and also indoor uses. The effective use of architectural LED Light Bulbs has made many commercial establishments and also residential houses look far more interesting. Soluna Green

[Converse]

Okay, I'm gonna show my ignorance here.  Are any of you using 'regular' florescent bulbs  (like those used in schools and other public buildings), or are ALL of you talking about using those special florescent "grow light"-type bulbs?

[Vlad Jovanovic]

I've used 'regular' T-8 "Daylight" tubes with wonderful results, kept them real nice and close to the plants though (2-6 inches). Though I must say, I will only use florescents (CFL or tubes) in an area that is NOT connected to the system. Like a separate sprouting table. I have been in offices where a florescent tube exploded out of the blue, and have heard of CFL's doing the same, so I am weary of poisoning an aquaponics system with the mercury from a broken florescent light.

If I had a small system, I might consider it,  where starting completely over would not be that catastrophic, but with 8 IBC grow beds and an additional 576 square feet of rafts, I'd considerate a real bummer of an ordeal to go through over a silly light. Has anyone ever had this happen? A CFL or tube just explode? 

[John Cubit]

I see this is rather old post but maybe I can get some advice.  I am really wondering if I am the only one using an incandescent grow light.  I currently have only on light, SYLVANIA 65-Watt BR30 Medium Base Soft White Incandescent Grow Light Bulb, and it was about 32" from my bed.  I have some plants doing fine, like a tomato and snow peas but I germinated those outside of the bed and the tomato was a cutting.  My lettuce leggy from seed and falls over and dies cause the stem can not support itself.

All the plants are different heights from 24" tall to 3" tall to even the seedlings.  How would I compensate for that without starting another bed, that I can not afford.  I did lower the light to 12" above the grow bed but the heat of the lamp raises the temp of the hydrocorn and in return raises the water temp 3 degrees.  Plus now the tomato is above the lamp.

Any thoughts on this?  I can adjust the lamp from day to day but that just is not practical.

Here is some photos of it all:

 Leggy lettuce seedlings

I have since lowered the light to 12" above bed.  This the the minimum distance recommended my Sylvania.