Leaves on Oncidium turning reddish - Too much light?

[LightsCameraFlowerspike]

Hi Everyone!

First post, woot!

I recently put my oncidium (and phals) under grow lights... Two reflective light fixtures with two CFL bulbs, one warm one cool, both 100W (1600 Lumens). Admittedly, I don't have much experience with grow lights, so I've been doing so experimentation.

Basically, after I put my oncidium under the lights the tops of the new growth have been turning a bit red. The tips are pretty close to the light to begin with, and I have the lights on for 14 hours a day, and the orchids are placed near a dim window where they receive about 5 hours of dim sunlight.

My question is, do you think i should simply move the lights higher? Or should I cut the hours the lights are on? I read that the higher the lights are, the less effective they are.. I'd appreciate any advice!

Thanks

[RandomGemini]

14 hours seems a bit much to me. I do 12 and my plants under my T5s receive NO sunlight at all.

I have my oncidiums set up with a foot between the fixture and the tops of their leaves, well, some of them anyway, I have a couple that are quite tall and the leaves almost touch the fixture, but the pbulbs are still over a foot below the lights. I grow my cattleya and brassavola at a distance of 6 inches from the same fixture. I used an outdoor plant stand to elevate them. I don't have any purple on my oncidiums and my biggest concern with them being that close to the fixture is that oncidiums do not need to dry out as much as cattleya do. Being close to the fixture means less moisture.

[LightsCameraFlowerspike]

Thank you! That's good to know.

I've read varying opinions on how long the lights should be on for.. the most I read was 16 hours. You are right though, 14 hours is a bit much. Phals obviously don't need that much light, but the light was supplemented to care for my precious oncidium Given that they do get some natural light already, I'll lower the time they're on.. but to find that perfect number is tricky.

[gngrhill]

From what I have read, the lights should mimic the length of day for most orchids as length of day can trigger blooming in some orchids. So going by that, I turn my lights on when the sun comes up and off when the sun goes down. Shorter in winter, longer in summer.

[LightsCameraFlowerspike]

While that makes a lot of sense, I've read that since the light input plants get from grow lights is lower, days can get extended. So for example, in the summer, one could have the lights on for 16 hour days, but in the winter lower it to 12 hour days. So the plants still recognize that the season has changed, and get enough energy from a light source at the same time. Someone correct me if I'm wrong

[Paul]

A reddish blush to the leaves is fine. However, that does tell you that you are at the upper limit of their happy zone ... any higher and you risk bleaching out or burning the leaves.