Light help in vivarium!

[getyaya]

Hello :

I'm new in the forum, but i have a few years in the cultivation of orchids. For some time here , I have several obsession with some genres , which they resist me .
Whereupon, I decided to make a terrarium for cold climate orchids .
I would cultivate genres: masdes, draculas, dendros ...

I have mounted the structure, which is 1.2 m high x 1 m long x 0.7 wide.
My problem to decide, after many readings, is the choice of the light.
I have two options :
-3 Of 39w T5HO ( silvania grolux , G5 or T5 FHO 39W/865 Luxline Plus)
- Led

The first option has the advantage of ease of installation and replacements , but the downside of extra spending instead of tubes and the power bill.
The led, in their favor have a higher light output and a greater life span.

Becouse this money saving and other advantages in terms of the choice of the ranges of light, I think the best would make me a dIY Led.

Someone could help me realize the watts and lumens range necessary for my case?

There is not much information about LED and orchids , I build on aquarium forums , reaching the conclusion that my measurements are equivalent (more or less)to a 120 liter aquarium . They use about 90 watts.

Hopefully come to a good end in this adventure .

Thanks in advantage

[WhiteRabbit]

[WhiteRabbit]

again
Good luck!

[naoki]

I'm not completely familiar with the genera you are interested in. I thought the 3 genera has fairly different light requirements (most Dendrobium requires higher light than other two).

I'm using red+blue LED, and I can grow/flower Phal species (not hybrids) with 10W/sqft. But this is at the low end. With white LED, plants may be happier with more (maybe 15-40W/sqft??). With 1.2m of height, you also need to worry about the shape of the light dispersion. I'm placing my plants about 20-30cm below the LED panel.

I personally like LED, but the efficiency is not that dramatically different from fluorescent light yet if you are talking about white light.

The summary of PPF efficiency:
High-end florescent light: about 1.2-1.3 micromoles/J
High-end Red:Blue grow light: 1.6 micromoles/J
High-end White:Red grow light: 1.37-1.51 micromoles/J

The 2nd link and the link to DavidCampen's post in the following link has the more detailed info:
LED related links

But the technology is changing quickly for white LED. I believe that the new COB (chip-on-board) type LED is supposed to be more efficient (although I haven't checked the number).

Also, you shouldn't assume that they will last for a long time. Some low quality ones fail quite quickly.

MJ related forums (e.g. rollitup.org) have lots of useful information about LED for plants.

[getyaya]

First at all, thanks to both for your time.

Naoki, too many thanks!!

I am aware of the height, but my idea was to keep the plants at different heights according to their light requirements and can range from 20-30cm to 1m away on light.
According to my readings, the masdes needs between 1000-1500 foot candle, and to make them bloom more than 1000. I have seen people who grows masdes, draculas and cool dendros in the same conditions.

The difference between putting fluorescent or LED, is not very drastic in terms of bill of light, but if it comes to maintenance fluorescent bulbs changes .

However, my idea is to make a combination of cool white ( 6500 ° K ) , blue, red and far red .
I have read , plants need more red than blue. What proportion do you have between red and blue ?

What worries me is to find a right combination between white, red and blue.
I´m thinking in a proportion of 7w-2r-1b, but i cant decided it!

I'm talking to an aquarium panel manufacturer ( with full spectrum ) , changing the LED 10000 ° K for cool white and blue for red .
The board have two dimmeables channels , one white - blue and the other red .

The other option , DIY , is to buy cree leds, so I read they offer a bigger efficience in terms of PAR.

I suppose that the pdf you mention the micromoles , you mean the PAR and I'm still a little lost in that.

I check the link of rollitup.org, but i read these forums in spanish languaje, more simple for me!
In my opinion, the reef forums are a step forward than canna.
But i´m not an expert! And there is a lot for learn.

Regards from Spain!!

[Ray]

I don't think you really need to supplement the blue - all white LEDs have a great deal of blue in their emitted spectra, and almost no red.

The plant lights I have custom-made are a combination of cool white, warm white, and red, and they are quite good for growth and flowering. The cool/warm white mix is more for aesthetics than plant spectrum, preventing the light from looking too blue or too yellow to the eye.

I am experimenting with a new fixture (80,000 lux a few inches from the light), and it has a similar mix.


Ray Barkalow
Sent using Tapatalk

[getyaya]

Hello again Ray .

I think you're right not to add more blue . So the problem is being partly resolved in colors.
But even so , I have several questions :
- How many watts you put in mine measures , I'm thinking about 90watts, is that right?

- As for the white, cool offers more blue and warm a little red, is this ok? do you use both or just the cool?
And in what proportion?

The manufacturer which I´m speaking, sent me a list of leds with which to make the table:
V 420nm , 440- 450nm B , Cyan 495nm , 535nm G 610nm Orange 660nm 630nm R R , W 3500K 4500K 2700K 8000K 7500K 6500K 14000K 12000K 16000K 10000K 18000K and 20000k .
Do you choose any of those?

There is a student, with final project, which talks about using far red in aquarium plants, (which can be extrapolated to all shade plants) and their need to compete for the search of light, this is obtained with 730nm.
The problem with this is the manufacturer don´t have this wavelength .

What good would that he could put the white in one channel and red one in another, both adjustable in intensity. I think is a big advantage.

Any experience with the far red ?, You see it necessary?
It is a color used in canna culture , plants are developed using it more and more compact foliage . But orchis are not canna!

Regards!

[naoki]

730nm is for phytochrome, which influences several aspects of photomorphogenesis. MJ is photoperiodic (the day length influence the flowering, they are short day plants), and lots of orchids are not (some are facultatively photoperiodic). For some short-day plants, if you shine FR at the very end of the day, you can induce flowering even during the summer. Inda Gro Pontoon uses this idea.

In addition to photoperiodism, I believe phytochromes are involved in etiolation (so it could influence the shape of plants). I personally wouldn't use it (aren't they less efficient and more expensive?) unless there is a strong evidence for orchids.

With the ratio, you might want to imitate some product with good reviews. Area51 uses XP-G outdoor white : XP-E Red (630nm) = 2:1. Apache tech uses 3:2 or 4:1. But they are more interested in maximizing PAR efficiency, so the orchid people who is interested in appearance may not like it.

Reef people needs more bluish light, but for land plants , I would say 2700K, 4500K, or 6500K may be good for the white, and 630 and/or 660nm for the red. It is probably difficult to optimize for orchids because there are lots of species in orchids, and slow growth make it difficult to get the quantitative results unlike MJ.

[Ray]

The new fixture I'm playing with has 50% 6500°K CCT, 25% 2700°K CCT, and 25% 652nm, with a total of 144W. The equivalent red/blue fixture is of higher chip-count and wattage, but white LEDs apparently emit more heat, so we had to cut it back.

The screw-into-incandescent lamps I have made are only 13W, consisting of 44 cold white, 12 warm white, 8 red chips, and two of them are so bright in my 20-high terrarium, that I had to elevate to top to increase the distance to the plants to 14"-20".

[naoki]

The mix sounds pretty promising, Ray. Is it 144W actual watt? Did you decide on the beam angle of the lens?