T5 lighting intensity

[dennis4246]

I have questions on light intensity. Will plants that fall in the medium range for fc be ok using a 2 ft 4 bulb system that produces right at 1000 fc or should I buy the 4 ft 4 bulb system that will put out over 1600 fc.

Thanks
Dennis4246

[CoolPhrog]

I'm growing several types of orchids under a one light t5 fixture and a 2 light fixture and everything seems happy...most have that purple tinge to them.

Den. abberans
Den. atroviolaceum
Max. uncata
Pleur. grobyi
Tolu. sylvestris
Ascocentrum curvifolium

To name a few. I've measured the fc for both of these fixtures and the meter reads lower than the plants "want" but like I said, all seem to be doing very well.

Here's a link to some articles that you may find helpful. I think the important thing to remember (and that I was reminded of) is that you can try growing under lights and if the plants are happy, they'll let you know.

A summary thread on lighting

[cb977]

You also need to consider how far above the plants those lights will hang, the further away they are, the lower the light value

[Ross]

I would opt for the 48" fixture, myself. The 24" is really only 22" (the tubes) and 1000 foot candles is pretty low for most orchids. I use 48" 4-tube fixture as well as a 48" 8-tube fixture. 1600-1800 should be about right for most medium light plants. As Sue stated, just move the light higher if the 48" proves too much. Hope this helps.

[purerookie]

Hi,

I have been using a metal halide lamp for my orchids. It has worked well. The cost is not as much as it seems because it works off a transformer. The initial cost is faily high depending on what wattage unit you would buy. I have never had very good results with flourescent lamps. See my post in identifying orchid forum for an example of the results I get using metal halide. I give my plants 16 hours of light per day and vary the intensity by placing the plants at different distances from the lamp.

[purerookie]

I forgot to list a site showing what I use. Sorry.

Hydroponics of Buffalo - Hydroponic Lights, Bulbs, Lamps and Supplies

[nhman]

As Ross has said, the 48 inch T5's are excellent and will get you enough FC to grow (or BURN) just about everything. I have grown and flowered Catts, Zygos and Dens under these lights without any issues other than having TOO MUCH light. Having too much light is kinda like having too much money: Good to have and there are good treatments and fixes for either problem. I just have only had the "too much light" issue to deal with, though.
Again, as Ross stated, just raise the lights up further. A good light meter is a great tool to have!!

[SheilaJ]

I agree - high output T5's are very bright, I started to burn some minicatts with them. They are very different from the older types of fluorescents.

I also agree about going with the 48" if you have the room. You'll fill up that space soon enough, I bet!