Artifical light overkill?/ yellowing leaves

[Birdieollie]

Hi all! I'm wondering if anyone can help me with growing under lights. I installed a 4ft HO T5 fluorescent fixture with eight bulbs. In hindsight I think I should have found an led equivalent, but now it's up. It's primarily for a lemon tree. I have a few orchids about 24" below the fixture. When aos recommends a 6" or 12" distance from fluorescent light, are they referring to a two bulb fixture? Should I be growing much farther below with an eight bulb fixture? At a 24" distance, the light meter reads around 1000-1100 fc. I know that pale green foliage is good, but I'm starting to wonder if they're getting too yellow. The leaves on the oldest pseudobulb of my prosthechea radiata are turning yellow yellow, and I don't know if that's due to too much light or some other cultural issue. There's a Wilsonara that is starting to look a bit yellowish. This phalenopsis bellina seems a nice yellow-green, but now I'm wondering if it's too much. There's a big box clearance cattleya whose newest leaf has some purplish coloration. Should I just lower them all six inches, and see what happens? It's just for winter. They'll all go outside in summer. Thanks so much for your advice.

[Birdieollie]

I forgot to mention, the light is on for 14 hours a day, and I'm thinking of reducing it to twelve. Someone in another group told me that that's probably too long.

[estación seca]

The AOS recommendation was probably for standard fluorescent tubes, not high-output.

The Phal. is getting too much light. The others look fine.

You need to pay attention to heat. HO tubes are hot. They may burn you if you touch them, and if plants are too close, leaves may sustain heat damage.

Most orchids we grow come from near the equator. 12 hours of light in summer and 10 in winter is fine. No sense paying for unnecessary electricity.

[Birdieollie]

Thanks estacion seca, they do get hot, and boy are they bright. I feel like I'm getting a tan under those lights. I'll reduce the hours and ease up the light on the phal. I moved it to the edge of the bulbs where it's not so strong, but I'll also lower it several inches.

[Leafmite]

I am growing with natural light after using three four foot, four tube fluorescent lights for a number of years. I needed the extra height on the shelves for the 'little' trees and passionfruit vines and I decided that the natural light would need to suffice. I rehomed the lights this past summer. They do create quite a bit of heat. A fan can be very helpful. If you are worried about the orchids, definitely move them away from the light or maybe shade them with other plants.

[Birdieollie]

Thanks Leafmite, I'll do that. I tucked a few of them under the lemon tree-- thought they might feel at home there. I'll pull them back a little until they keep a bit greener.

[Leafmite]

Lemon trees are quite nice. I have a Meyer's lemon tree.

[Birdieollie]

That's what mine is! A meyer lemon. I bought it online about a month ago. I probably should have waited until spring, but it was a great price, and impulses prevailed. It's dropped a lot of leaves, but I'm sure it'll be fine. It also started budding heavily soon after going under the T5 lights. I have a weakness for all things fragrant, and this is one of my favorites. It'll be blooming alongside my Onc. Twinkles!