help with new grow light T5

[nicki]

I finally purchased a light fixture set for my orchids. And a shelf for everything. I've never used grow lights before. Generally my orchids are by a window and get whatever natural light comes in which can be bright with some direct in the evening as the sun sets. Also this passing summer I put some of my orchids on the porch which now need to come in.
I can use some advice on using artificial combined with natural light. How often do I use the grow lights? How far should my plants be from the lights? Are the bulbs I have ok? Any tips for someone new to this...

I have...

-T5 4 tube 2' fixture that came with 4 64k bulbs
-2 shelves under the lights for plants
-mix of plants; 4 Phal, Mokara, 1 Catt, 5 Epc, 2 Blc, 1 Blptm (not sure if any of those have had name changes...)
-also have african violets and various succulents if anyone has experience there

[Raver]

I grow under lights too (t5's). If your plants get natural light through out the day then you can use the artificial light for only a few hours as supplement lighting but if your plants get hardly any artificial light you can use the t5 all day as your main lighting. I leave my lights on 16 hours a day during the summer, 14 hours for fall/spring and 12 for winter. You will hear a lot of people say that plants need to be 6" or closer to the lights but i have find that when using t5's, this is not the case. I put my vanda about 4" away from the light any closer than that and it starts yellowing, dendrobiums 6", catts/phrags 6-8", Oncidiums 8-10", phals/paphs/AV's and any other low light plants 10-14". I have tried putting alot of this plants closer to the lights but alot of them turn yellow or purple.

[nicki]

Thanks Bryon. Do you water or mist your plants while they are under the lights? Or do you do that in another area?

[Zozzl]

With the african violets and gesneriads it just depends. Some of mine I move within 6 inches and then other about a foot or more away. The variegated AVs like less light.

[Raver]

I mist them while under the lights but becareful lol (i am not). I dont mist them that much anymore because i have them in a small room and i am able to keep humidity at 50-70% all the time

[nicki]

Thanks

[David Boyle]

I too use T5's. I have 2 t5's. You mentioned distance away from the lights. What part of the plant are you measuring from. Are Cattleya orchids 5-8 inches away from the top of the leaves or from the top of the pot or somewhere in between. This is a great way to experiment but I need to know from where to where you are measuring and how many lights?

Thanks

David Boyle

[Raver]

All the measurements are from the top of the leaves, Most of my orchids have a purple tinge on them or are light green in color(like apple green). I have two
4 feet 8 bulb t5's they are 4 feet long and 2 feet wide. I use 4 3000 kelvin bulbs and 4 6500 kelvin bulbs. If i put my catts(leaves) closer than 6" to the lights, they start to turn yellow. I have a neofinetia falcata that is 1 ft away fromt the light and the are a light green, i might move it an inch or 2 farther away from the light. An inch or so away from the light i get 5,000 foot candles, 18 inches away from the light i get anywhere from 1,000 to 1,600 foot candles, it depends from where you measure.

[David Boyle]

Thank you. I may have my plants too close although I have two 20 inch T5's above the shelf. There may not be quite as much light. I am not seeing yellowing on the Cattleyas but I was going to put my oncidium orchids under similar lights. Now I know where to put them. Thank you.

[Raver]

Anytime, i just took some picture to show you what i am talking about. I will post them soon.