Just bought 3 High Output T5 light fixtures... have questions...
 

Hello all of you who grow under lights...

I just bought 3 - 4' High Output T5 light fixtures from e-bay... now I'm second guessing my purchase. Each fixture has two bulbs, one in the blue spectrum and one in the red spectrum.

I have a 4' 4-tier metal shelf unit by an east facing window where I keep my orchids... they are a mix of catleyas, dens and phals.

I've had good luck with my phals and paphs, but I could only get 2 of my catts to flower. So I thought I should boost the lighting.

The plan is to strap one of these lights above each shelf, but I have another problem... humidity. So I was thinking about covering the sides of the shelf unit with vinyl and adding humidity trays underneath.

Just now I read about how hot these lights get.... which means that it wouldn't be safe to enclose it all in clear vinyl... How hot do these things actually get?

What would you suggest I do to best solve my problem? some of my plants are getting really dry and wrinkled, especially my cattleyas. I must add more humidity and light.

Any suggestion is much appreciated.

About a year ago I switched from T12 to 4 ft 4-bulb HO T5 fixtures. I grow mainly Paphs and Phals with one token Catt and a couple others. I did have some problems with heat last summer when we got some unusually hot weather, but other than that it hasn't been a problem for me. The bulbs do put out some heat.
How close do you have the bulbs to the plants? If the plants aren't used to growing under lights, you may need to start the fixtures a little further away and move them closer. The humidity in my house runs about 50% most of the time and I don't do anything to increase humidity except misting when it gets hot in the summer. I know some people use ultrasonic misters to increase humidity. I have heard of people using vinyl to enclose their growing area, but if you are getting a lot of heat, you may need some fans or other method to remove the heat. Also, are you watering enough? With increased heat, things will dry out faster. I find that a higher moisture-retaining medium works best for my conditions. My Catt is even doing great in pure sphagnum moss.

Any time you change aspects of your culture, you will likely have to do other adjustments as well. You may have to change watering, potting medium, etc. You can't assume that you will be doing the same things you were before adding the lights and often it requires some experimentation to find the right combination.

Do you have any photos of the setup? That may help in giving advice.

Susan

Thanks Susan for the quick response. Actually I haven't received them in the mail yet. So I don't have anything set up. I should by next week or so.

I'm currently not doing anything for humidity and my humidity meter is only registering 20% - 30% or so... which is way low.

I'm watering them once a week which is fine for my phals, but I'm thinking I'm under-watering for my cats which are the ones that are starting to shrivel...

I'm way busy during weekdays... so I'll have to make some adjustments especially after the lights are set up.

Thanks for the fan suggestions... I'll certainly do that. I may have to add some sphag to the medium (currently a mix of bark, perlite and coconut husks.

The first two things I learned after buying T5 bulbs was that I needed a fan and my orchids would need more frequent watering. Growing conditions vary so this may or may not be true in your case but it is food for thought. In my case the T5 lights required a change in culture but they have helped me bloom Catts, Phals, Dens, and a specimen size Bulbophyllum echinolabium. Once you get everything dialed in you will love these lights!

I use a vinyl enclosure but during the day I have the front open and only close it at night. The humidity builds up at night with out the lights. I have 3 trays and use a small fan ($6.00 from walmart) on each shelf. What works for one grower will not work for all growers but it works just fine for me. In the summer if it is rather hot I put an extra one on the top shelf, blowing outward.

Marilyn

Thank you for the suggestions. I went to about 5 retailers today and not one has little fans! I guess its so darn cold here they won't be getting fans in until the summer... ugh.

I'm very excited to get this all set up! I'll post a picture when I get it up!

for fans you can try online computer parts suppliers. They are referred to as cushion fans and are used to keep the cpu cool in computer cases. Most are 12 volts but there are some that have been rigged to take house current. They can run for a long time. You are looking for something that can run non-stop until it fails.
Nick

Radio Shack sells 120V versions of computer fans.