New growing space - help needed!

[NKOrchid]

Hello everyone,

I'm building my own growing space which consist of one aluminum bookshelf (3 shelves). I've also bought two computer fans. My thought is to wrap the shelves in see through plastic bags (yes, this is quite low budget) and install the fans, (perhaps a humidifier or two) and some lights in the space.
I've looked at some lights and I've done my research, but I'm still so confused. As far as I've understood 1 lumen = 1 lux per m2. The lights I'm thinking of buying (setup per shelf) is one 150W 2700K and one 250W 6500K - one shelf is about 0,36 m2. The 150W and 200W combined has an output of approximately 25.000 lumens which is 25.000 lux per m2, but since the space isn't 1 m2, the lux is way higher. Even if I round up to 0,5 m2 space the lux will be doubled to 50.000, which is about 4600 foot candles. That's a lot of light and enough for post orchids (and too much for some), as far as I know.
Are my calculations correct? Or am I missing something?
Also, I'm a little afraid of the heat these bulbs will put out. My space isn't big and the shelves are grid, so all the plants on the different shelves share the same air and temperature so the space in total will maybe have 2 - 3 of each bulb.

Does anyone have any experience with having a lot of watts in a very small space? And does it sound like this would be enough lumens or is it too much? I'm thinking of using tin foil as reflector.
The plants I have are 1 phal, 2 cymbidiums, 3 oncidiums, 2 dendrobiums and one miltoniopsis.

Looking forward to your advice and sorry for the messy post!

[Tetra73]

How big are the shelves...because most orchids you have there can grow pretty tall. Oncidiums can have a 3ft tall flower spike. If your dendrobiums are the phal type, additional to the 2ft+ cane, it would shoot out another 1ft to 2ft long flower spike as well.

What kind of light bulbs you are planning to get? I won't go by the wattage. Instead, look for the lumen rating.

[NKOrchid]

Some of them are quite tall, which is also kind of an issue. I have a cymbidium that's 23.6 inches tall. One of the dendrobiums is 21.6 inches.
The shelves are 14.1 inches x 35.4 inches. I can change the distance between the shelves whenever I want and right now there's one space from shelf to shelf that's 27.5 inches, another that's 23.6 inches and the last one's 15.7 inches.

The bulbs are CFLs and come in 2700K and 6500K in both 150W and 250W. The 150W are about 9000 lumens and the 200W are about 15000 lumens.

Oh, and since the plants vary a lot in size, it's very different from plant to plant how far it is from the bulb.

[Tetra73]

Skip CFLs because there are better alternatives. Get these. I have 4 of them in my fixture, with a combined lumen of 6000. Under 6 inches, I am getting about under 3000 foot-candles. That should be enough for most orchids. It does not generate a lot of heat either. I can even touch it with my bare hands. They are also available in both 5000k and 2700k too.

Philips 100W Equivalent Daylight LED Light Bulb (2-Pack)-462002 - The Home Depot

Remember that when growing under light, you can compensate for light intensity with longer photo period. 15 hours to 16 hours photo period should be fine and you only need half of the light intensity.

[NKOrchid]

I need way more than 6000 lumens. If one of my shelves got 6000 lux, which would be 12000 lux with my space, that'd only be 1000 FC, which at 16 hours would be 2000 FC. They get absolutely no light from the window and I have plants that require 3000 FC.
Also, I need something that I can hang horizontally, so preferably something that's longer. If it's vertical it takes up too much space and they start touching some of the plants.
One of my biggest problems are definitely space. This is the bulb I'm looking at: EnviroGro CFL Lamp 150 Watts White (Supercool)

[Tetra73]

I thought you are going to have light fixtures on each shelf??? I just don't see it work to have a single fixture for the entire shelves because...CFL light can not penetrate well as the distance to the light gets too far. They produce A LOT of heat...even with my 23w. You may try some t5 2ft or 4ft fixture (2 strips) on each shelf. With a t5 2 strip fixture, you can get about 4000 lumen (2ft) to 6000 lumen (4ft), per shelf. That's more than enough for most orchids, other than vanda.

---------- Post added at 10:35 AM ---------- Previous post was at 10:28 AM ----------

Also, lumen rating is only half of the issue. The other have is the actual intensity. With my 6000 lumen LED bulb fixture, I am getting close to 4000 foot-candles, with the distance under 6". Under a foot, I am getting close to 3000. That's A LOT of light for a 15 hours photo period. My dendrobium are lime green. My oncidium has yellow edges on the leaves. This indicates they are getting enough light.

I have a light meter to measure the actual light intensity.

[Leafmite]

I ran out of windows so I bought a wire shelf and, lately, another like it. The shelves can be adjusted (though I find it a pain to do so) and lights hook neatly under them with S-hooks to maximize the space. I have the one shelving unit covered with plastic and the other has plastic under to prevent damage. I line each shelf with thick plastic to protect the lights (cheap clear plastic tablecloth, cut) and I have lids from bins as trays. The lights and shelves were the big investment but I felt it was well worth it. I also have a two foot, two bulb sunblaze which does well for the low light plants. It is a good lamp but the others are better for hooking under the shelf. Good luck with your set up!

Here is the link for the wire shelf:

https://www.amazon.com/Alera-Complet...+wire+shelving

Here is a link for four foot lights:

https://www.amazon.com/Hydrofarm-Flu...+t5+grow+light


The two foot sunblaze:

https://www.amazon.com/Sun-Blaze-960...un+Blaze+T5-24

And here is an example of an S-hook:

Amazon.com: Gamecraft 3/8" Galvanized Large S-Hook: Patio, Lawn & Garden

[Tetra73]

Here is my 6000 lumen LED fixture. Ever since this morning, I trimmed off 2 inches off the top. This would enable me to get my fixture much closer to the plants. If I stick my light meter in there, it would read EV 14.5 at ISO 100. That's equvlient to 5000 foot candles. About 3000+ fc outside the box. And just under 2000 fc up to 2ft.

mygrowtentlight2 by vracing, on Flickr

[NKOrchid]

Tetra73: I'm gonna have about two bulbs per shelf. One of each color. I don't get how your 6000 lumens get you 4000 FC - your space would have to be barely enough for one orchid. Sorry if I'm being annoying or dumb, but I just don't get it.
As I initially wrote, what I've understood is that 1 lumen = 1 lux per m2. 1100 lux per m2 is about 100 FC per m2. My orchids need between 1500 FC - 3000 FC so I'd need an output of 20000 lumens running for 16 hours a day to make them all more or less happy. Thanks for taking time to reply!

Leafmite: Your shelf is exactly the one I have minus the wheels! I've checked out your links and the lighting seems okay and they would fit in my space. I'd like to know exactly how many lumens they are. It only states that it's extremely high lumen output per watt. I guess I'm a little fastidious with the information.

[Tetra73]

I think you did your math wrong. I have a photography light meter here. These bulbs are rate 1500 lumen each. Totalling 6000 lumen..probably rated At the bulb level. And my light meter is giving me an exposure value of 14.5, almost 15 when I stick my light meter inside my light fixture. According to the chart here, Conversion Chart at 14.5 ev, that's roughly 5300 fc.

My light meter does not lie. My orchids don't lie to me either. I am just horrified that you are planning to stick 3 9000 lumen CFL bulbs on your orchids.

---------- Post added at 01:22 PM ---------- Previous post was at 01:12 PM ----------

Also, the lumen and wattage on t5 bulbs are pretty standard. You get more lumen and more wattage with a longer tube. A 4ft bulb would give you about 2700, 28w. 4 of them would give you 10000+ lumen.

What T5 lamps are available? | T5 Fluorescent Systems | Lighting Answers | NLPIP


That's just on paper until you actually measure the light output at a specific distance. The quality of the reflector plays a role too. Trust me, you can probably fire your orchids placing 4 t5 bulbs 4ft long less than 6" above the plants.