T5 setup questions - Orchid Board

Norton · #1 08-03-2009, 08:31 PM

Hello all. My question to the light gurus is about what type of T5 setup I need for my grow space. I currently have a shop light with two 4 foot daylights. My noid Phal is about six inches away and seems happy. So far I have new roots and a new leaf poking out. However, I also have an Oncidium Twinkle and a Phal type Den that are outside on my deck. They are happy there for now but when the weather takes a dive I want to keep them inside. My space is 30 inches high 49 inches wide and 15 across. How many four foot bulbs would be best,2 or 4? I would also like to add a smaller Cattleya to my collection. I guess I am just having a hard time figuring out how to balance the light requirements for these different orchids. Any help is much appreciated!

Ross · #2 08-03-2009, 11:46 PM

I recommend a 4-tube 48" fixture. Firstly, it won't be 48" long. A typical 4-tube fixture designed for t5 straight tubes will be 11" wide and 46.5" long. This seems to fit your area pretty well. Remember the strongest (brightest) light will be in center and weakest light at ends. Place the Phals at ends and the Dendro and Oncidium in center. Run the fixture from an appliance timer and set for 14 hours or so on cycle in winter.

Norton · #3 08-04-2009, 12:34 AM

Thanks for the help,Ross. My main concern is not being to get the phal far enough from the lights and burning it. I have heard some people did not realize just how much light this type of setup produces and had to adjust the grow space to get the plants the proper distance. I have no other suitable space so this is a critical issue.

jkhom · #4 08-04-2009, 07:00 AM

Just one note to add.
T5 fixtures come both normal and high output.
The ones tha are available from the box stores are normal wattage, whereas most plant light suppliers sell high output.

Ross · #5 08-04-2009, 09:20 AM

Quote:

Originally Posted by Norton

Thanks for the help,Ross. My main concern is not being to get the phal far enough from the lights and burning it. I have heard some people did not realize just how much light this type of setup produces and had to adjust the grow space to get the plants the proper distance. I have no other suitable space so this is a critical issue.

I wouldn't worry about the Phal. It's doubtfull you can burn it under t5 HO tubes if they are located high enough for clearance for the big (tall) plants. I have mine in a south window and have t5 compacts right next to them besides.

TylerK · #6 08-05-2009, 09:24 AM

One thing you don't mention that should be taken into consideration is how enclosed your space is. T5 fixtures output a considerable amount of heat compared to other fluorescent fixtures. I used to have a setup in a closet, and without added ventilation and a humidifier I was frying my orchids....dried them to a crisp.

Tyler

Ross · #7 08-05-2009, 09:32 AM

T5 lamps run at 95 degrees F. That is not overly hot, unless no ventilation is provided. I run a simple room fan on mine to "blow away" the heat. I have several setups including the 48" light bank on my tank which is in an enclosed space in my basement. I have no special heat issues. Yes t5 fixtures run warm, but unless the fixture is in an unvented small space (not particularly good for the plants) there should be no issues. All spaces for orchids should have plenty of air movement and/or ventilation.

TylerK · #8 08-05-2009, 09:42 AM

It was more an issue of humidity. The added heat from the lamp dropped the mositure levels considerably. I eventually did install a tank in the closet for the more moisture sensitive mounted plants and they really took off after that, but then I also added a fogger setup to the tank which also served to cool things off.

Only the cooler growing orchids suffered from the heat alone, but everything outside the tank suffered from the lack of humidity. I eventually sorted things out by installing a fan and a humidifier in the area. It's definately something that needs to be taken into consideration if one is used to growing under less powerful fluorecents that don't raise the temperatures quite so much.

Norton · #9 08-05-2009, 08:14 PM

Good points guys. My space is an unused kitchen counter. There is a ceiling fan almost overhead that helps keep the air moving. I also have a humidifier in the grow space to help raise the humidity. We have central air as well that keeps the house at a reasonable temperature. I know I can adjust these things. One thing I cannot adjust is the space I have to work with. I have 30 inches from where the lights will hang to the counter where the plants sit. If the light is too intense at this level, I have no way to fix it. Just want to make sure I choose the right set up. I would hate to spend 150 dollars or so and regret it.

Norton · #10 08-05-2009, 08:22 PM

Good points guys. My space is an unused kitchen counter. There is a ceiling fan almost overhead that helps keep the air moving. I also have a humidifier in the grow space to help raise the humidity. We have central air as well that keeps the house at a reasonable temperature. I know I can adjust these things. One thing I cannot adjust is the space I have to work with. I have 30 inches from where the lights will hang to the counter where the plants sit. If the light is too intense at this level, I have no way to fix it. Just want to make sure I choose the right set up. I would hate to spend 150 dollars or so and regret it.