Lighting Questions

[orion141]

Hi everyone! I have been lurking for a little while and reading as much as I can, but I have a few questions I would like your opinions/advice one. I currently own 6 cattleyas, 2 phalenopsis, 2 oncidiums, and a paph. I live in a 2 story town house in central/west florida that has only north and south facing windows. As such the lighting in the winter is direct sun coming through the south facing windows starting around 12-1 PM. However during the summer none of my windows really get any direct sunlight. As such I have been considering the addition of a wire rack with some 4ft x4 bulb fluorescent fixtures to supplement my light. This leads me to my questions. Do you find that the 4'x4bulb fluorescent fixtures ( I am looking at the hydrofarm ones) generate a lot of heat for the plants situated directly above (from the internal ballast/lights). Also considering that some of my plants are lower light orchids (paph and phals) would you recommend getting a 4'ft x 2bulb fixture for a different shelf on the wire rack for them? I have just purchased a light meter that should be arriving today to get some better light measurements in my windows. Thanks in advance!

[billc]

I use the Hyrdrofarm 4 bulb 4' lights and I am well pleased with them. They do generate some heat, but if you have the shelves open that shouldn't be a problem.
I would keep the lower light plants further from the light rather than buy a 2' light. You can place the catts on inverted pots or make a small shelf to raise them up.

Bill

[orion141]

Originally Posted by billc

I use the Hyrdrofarm 4 bulb 4' lights and I am well pleased with them. They do generate some heat, but if you have the shelves open that shouldn't be a problem.
I would keep the lower light plants further from the light rather than buy a 2' light. You can place the catts on inverted pots or make a small shelf to raise them up.

Bill

Thanks for the reply. Do you have any natural light coming to your plants as well, or just the artificial light?

[jeremyinsf]

I had to take some bulbs out of my 4x4's. In fact, now, none of my shelves has 4 bulbs pointing at it.

Having said that, distance, how big of an area you are lighting, and what kind of plants makes a big difference.

With a couple exceptions, all my plants under the lights are Paphs.

[orion141]

Do you all find that you are able to flower catt's and other higher light plants with the 4bulb t5ho fixtures. I am reading that some people are able to, but I saw some readings statin that you only get about 1200 footcandles at 6 inches, which doesnt seem like enough for catts and other high light orchids.

Thanks!

[Sun rm.N.E.]

I just started using a Hydrofarm 4bulb t5HO fixture this Winter and was surprised by how much light it produces. In fact, my cattleyas and brassavolas all turned beat red under the lamps at first and yes they are all blooming. They were used to getting Full Sun until 1 PM in in an East facing sun room closed to the glass wall and ceiling but light levels had decreased considerably by November, in the North East, when I moved them under lights and even Brassavolas found the need to put up red sunscreen to get used to the additional light.

So you have to make some calculations about the distance between the lights to the top of each plant, the number of hours you run your lights, the ambient temperature, and whether there are fans, and what will be the difference between the light your plants are now accustomed to. I cannot speak to running these light in high ambient temperatures since I only use them in the cold weather in the Winter when my natural light is reduced and room temperature runs 67-75 F. Since I have hot air heating and low humidity, I do not use fans. This sounds complicated but it will all work out with trial and error. Just look at the color of the leaves as an indicator.

I suggest You experiment to accommodate your collection by putting plants at different heights like BillC suggested, starting further and moving them closer to light as they accommodate. Hope my example can help. There is 2ft distance between the shelves but once the light takes up space, plus the 6 in minimum heigh of pots I use, the biggest distance between the light and the top of my shortest plants was 10 in. Obviously not suitable for my tallest orchids and if I were to grow Phaleonopsis I would definitely start them at a further distance from 4 T5 's then available in my current setup. So if you really want to bloom Phals and Cattleyas under one light it can be done but you need a lot of space to move them up and down from the lights, at least initially, to avoid burring the leaves. When you figure all this out you can make 2 or 3 levels and work on the aesthetic.

[Ray]

If you decide to go with the Hydrofarm fixtures, check out my store (shop.firstrays.com), as I am a discount Hydrofarm reseller, offering in the neighborhood of 10%-15% off of their suggested retail prices.

[billc]

Originally Posted by orion141

Thanks for the reply. Do you have any natural light coming to your plants as well, or just the artificial light?

The plants I have under lights only get artificial light. Mostly paphs, phals and masdies now. As Jeremy said for paphs and phals I've also taken out a bulb. My paphs are getting the maximum light they can handle, They actually look sort of bleached.
My few catts have gotten too large for my shelves but when they were under the lights they did great.

Bill

[jeremyinsf]

How many hours, Bill? I'm going to reduce mine on the timer. Too much light right now.

[billc]

Jeremy, 12 hrs on, 12 hrs off. The leaf surfaces are about 14-17 in from the bulbs. I think the reflective mylar in the new grow tent is giving them a lot more light than I thought it would.

Bill