Quantcast

T5 fluorescent lights and orchids

Slippertalk Orchid Forum

Help Support Slippertalk Orchid Forum:

P

PHRAG

Guest
I just got my first bank of T5 fluorescent lights. WOW! They are bright. I have two cool and two warm bulbs per fixture. I am getting ready to hang them in my shelves, but I have a couple of questions.

Before I ask, I understand that light is not an easy thing to measure for the average joe. So before you post a long rant about how "less than ideal" my methods are, realize that I already know that. But close enough is a good starting point.

Ok, I have a light meter that measures in Lux. 10 lux = 1 footcandle

I measured the light output from one of the fixtures hanging just a few inches (less than 6) above the leaf tips of one of my phrags. I moved the light meter around the phrag and took several readings to get an idea of what kind of range I was getting. The meter was reading 20,000 to 40,000 lux easily. That is 4000 footcandles in the brightest zone.

I am hanging the lights over my paphs and phrags. Here are some questions.

1. If I am going to leave my lights on for twelve hours a day by timer, how many footcandles should be hitting the leaves for both paph and phrag?

2. Is twelve hours sufficient, or should I bump that up to 16?
 
P

PHRAG

Guest
And one question in general about fluorescent lights. Are they going to explode? I saw these "bulb guards" that are clear plastic tubes that fit over the bulbs to prevent broken glass from going everywhere. Is that just if someone hits the lights, or are fluorescent lights prone to pop on their own? I have this nightmare about digging shards of glass out of all my pots.
 

Jon in SW Ohio

Reefer, the legal kind
Joined
Jun 9, 2006
Messages
998
Reaction score
0
Location
Springboro, Ohio
T5 lights are commonly used in the reef aquarium hobby as an alternative to metal halides. Most tests put them on par with MH with the added bonus of running much cooler, and they come in MANY wavelengths. Congrats on them, they are one of the best lights you can get IMHO.

As for bulbguards, again mostly used for applications above a tank without a lid. Basically, they prevent buildup of saltcreep on the bulbs and drastic temperature swings. If the lights get hot enough, splashing them with cool water will make them explode(ever take a squit gun to an incandescent lamp that's been on a while? POP!!) and those plastic covers prevent that as well.

Watch for burning!! I know people using them over their reeftanks and bleaching their sunloving corals (equilivalent of full sun plants getting burnt). Start the bulbs farther away and slowly acclimate the plants to be closer to the bulbs.

Most footcandle ratings you hear for plants are mostly directed at greenhouse growers where that is the peak lighting for a short period. When using artificial lighting, you get constant lighting and don't necessarily need that intense of lighting. WATCH YOUR PLANTS!!! They will tell you if they are getting too much or too little light. Always better to be cautious when adapting plants to new lighting(and corals too). For plants under HPS or fluorescents, I go 14-16 hours on just to make up for the lower intensity of the lighting. This whould be fine for you, just as long as they are sufficiently far away from the bulbs. I can't stress acclimation enough!

Jon
________
Ford F-650 History
 
Last edited:
P

PHRAG

Guest
Jon in SW Ohio said:
T5 lights are commonly used in the reef aquarium hobby as an alternative to metal halides. Most tests put them on par with MH with the added bonus of running much cooler, and they come in MANY wavelengths. Congrats on them, they are one of the best lights you can get IMHO.
That's good to hear. I have been putting off buying lights for too long. I finally found some new, two foot fixtures with four bulbs for a decent price so I jumped on it. I love eBay. They work well on my 32 inch shelves.

Jon in SW Ohio said:
As for bulbguards, again mostly used for applications above a tank without a lid. Basically, they prevent buildup of saltcreep on the bulbs and drastic temperature swings. If the lights get hot enough, splashing them with cool water will make them explode(ever take a squit gun to an incandescent lamp that's been on a while? POP!!) and those plastic covers prevent that as well.
Well, I don't water in the greenhouse, so I don't think I have to worry about that. I think I will pass on them.

Jon in SW Ohio said:
Watch for burning!! I know people using them over their reeftanks and bleaching their sunloving corals (equilivalent of full sun plants getting burnt). Start the bulbs farther away and slowly acclimate the plants to be closer to the bulbs.
They are on adjustable chains. Should I set them at the highest level and lower them a little more each week until the plants get acclimated? That makes sense.

Jon in SW Ohio said:
Most footcandle ratings you hear for plants are mostly directed at greenhouse growers where that is the peak lighting for a short period. When using artificial lighting, you get constant lighting and don't necessarily need that intense of lighting. WATCH YOUR PLANTS!!! They will tell you if they are getting too much or too little light. Always better to be cautious when adapting plants to new lighting(and corals too). For plants under HPS or fluorescents, I go 14-16 hours on just to make up for the lower intensity of the lighting. This whould be fine for you, just as long as they are sufficiently far away from the bulbs. I can't stress acclimation enough!
What is the reaction of paphs and phrags to too much light? Do they start to yellow before they burn? Or other color changes? I just need to know what to look for.
 

Jon in SW Ohio

Reefer, the legal kind
Joined
Jun 9, 2006
Messages
998
Reaction score
0
Location
Springboro, Ohio
Yup, be on the lookout for yellowing, fading, and browning tips. Obviously, maudiae types and other "thin leaved" ones will be much more susceptable to burning than multifloral strap leaved ones.

I would start at the highest setting and work my way down over a couple weeks. What wattage are they?

Jon
________
Cannabis seeds
 
Last edited:
P

PHRAG

Guest
To be more specific, I am going to have one light hanging over my phrags, which are all besseae species and besseae parented hybrids. I will have another light over my paphs, which are roths and phils.

They are New Wave T5 fixtures, 2 feet long with four 24 watt bulbs. Two 3000K Warm and 6500K Cool bulbs per fixture. I got them for $130 shipped including the bulbs.
 

Rick

Well-Known Member
Joined
Jun 9, 2006
Messages
12,765
Reaction score
3
Location
Leiper's Fork, TN
Phrag
What does your meter read in noonday sunlight? Your values for the T5's seem a bit high.

I took our lab certified/calibrated meter outside and only got about 5000fc.

Numbers I like for paph species.

Barbata types 600 to 1500 fc. Multiflorals 2000 to 3000. Other types somewhere in between with seasonal differences. I like 1500 for armeniacum in the summer, but 2500 in the late fall and winter.

Many in the section paphiopedilum span the whole range too. Henryanum is doing fine for me in barbata light, but druryi is right up next to the philipinenese getting blasted.
 
P

PHRAG

Guest
Hi Rick,

I will take the meter outside today and try and get some readings. I only got a 4000fc reading when the meter was nearly touching the bulb. I mostly got 1000fc to 2000fc readings within six inches of the bulbs.

So I guess my multifloral paph species will need to be gradually acclimated to the lights hanging within six inches of the bulbs.
 

Rick

Well-Known Member
Joined
Jun 9, 2006
Messages
12,765
Reaction score
3
Location
Leiper's Fork, TN
You might be more accurate than it origionally sounded. 1000 to 2000 at 6" from the bulb sounds fairly normal. When you said 4000 at the leaf surface (assuming that was also about 6" from the bulb) sounded high. As you noticed fourescents drop off very quickly as you move away from the bulb compared to MH bulbs.

Your multis can probably go to at least 2000 fc without too much acclimation, although it seems that my supardii seems to be much happier (better leaf color) in the shade of my roths, kolo, and phili's than when it was right up there with them in the bright light.
 

Latest posts

Top