A summary thread on lighting

[jebar77]

i have 2 400w mh fixtures plus a T8 fixture over everything. i believe i have a 10k, 6500k mh bulbs and im not sure about the t8 bulbs .... they are the run of the mill lowes replacement bulbs for the fixture, for me i need the extra heat during the winter months, all my plants are in the basement and i dont want to use the forced hot air to warm the plants and dry them out... even during the summer months i like to have the heat from the fixtures because the basement still stays a bit cooler than the outside.

[Becka]

Can I use any CFL to provide light to my orchids? What about a CFL that provides light for reptiles?

I am looking for a non-expensive set-up to supplement the natural light my orchids receive.

[Magnus A]

Originally Posted by Becka

Can I use any CFL to provide light to my orchids? What about a CFL that provides light for reptiles?

I am looking for a non-expensive set-up to supplement the natural light my orchids receive.

Yes you can!

Go for a "full Spectrum" bulb at a color temperature around 4000-6500 Kelvin.
Do not bother for special lampsfor reptiles as they usually give "alot" NIR-light (near infra red). I would neither bother about special plant lamps as the light look terribly and the cost is much higher without beeing sufficient better!


Some information:
There is nothing called "degree Kelvin" (°K), you do not use "degree" when measuring Kelvin temperatures. You though do when you talk about degree Celsius (°C).

/M

[Andre]

I have a 8 bulb t5 fixture with 4 foot 54 watt full spectrum tubes. How close is too close (other than overheating plants), how far should I place my Catts. If they are very close (5 inches) do I only get the benefit of two or three of the tubes versus the benefit of all 8 tubes. I grow Catt. walkerianas, and nobiliors. They are not booming but some of them have a suntan. Tubes are on for 13-14 hours.

[Ray]

No, I am not referring to any specific brand, nor am I saying that it is universally true.

If you look at the absorption spectrum of chlorophyll, you will find that the red peak at roughly 660nm is roughly 90% of the height of the blue one at 430nm.

A 6400°K black body radiator will also have that same intensity ratio of those wavelengths, but will also have greater intensity in-between.

A plant light that is rated at 6400°K corrected color temperature is likely to have emissions at those wavelengths that match those ratios reasonably well, while a 6400°K CCT fluorescent not made for plants may not.

[estación seca]

This thread hasn't been updated in a long time. Plants' light requirements have not changed, but technology has changed a lot since 2013. If you're contemplating buying grow lights, look at newer threads in this forum for more up-to-date information on equipment. The information here on what plants need is still good.

[WaterWitchin]

Originally Posted by estación seca

This thread hasn't been updated in a long time. Plants' light requirements have not changed, but technology has changed a lot since 2013. If you're contemplating buying grow lights, look at newer threads in this forum for more up-to-date information on equipment. The information here on what plants need is still good.

I'd never looked at this sticky, but I agree with you ES. I'm going to unstick it, as the information is outdated. And to someone newer coming along who wants to learn, it's not helpful overall. Thanks for pointing it out.

If someone knowledgeable about lights and lighting wants to step up to the plate and give a synopsis of present knowledge and technology, that would be grand.

[Steve83]

I'm pretty familiar with, and have grown under a variety of lights (cfl, t5, led, hid).

Its really down to led vs hid at this point. Even among leds, you have cob, board style units, strips (great for shelves), conversions etc. The biggest issues with many led lamps (it isn't rocket science to build one), are that they are not driven to the wattage specified ie. claims to be 200w, but draws much less when measured.

[Steve83]

I should have also elaborated, that I am working on a write-up reagrding my trials and tribulations with hid growing in a tent.

But could also do a separate piece covering led and hid lighting, and recommendations for layout.