experiences led

[moof]

Im curious about the results you'll have. Sounds interesting for a smaller setup.

cheers

Peter

[moof]

whoops, double-post. Sorry

Edited November 11, 2013 by moof

[pmatil]

Very nice Karl!

[Karl H.]

Hello,

i will make some photos of plants growing under the same light mixture soon.

I also finished the setup with a new controller board. Five LED modules can be connected together onto one power supply.

I also put two temperature controlled fans on the heat sink.

greetings

Karl

[vincent]

Hi everyone,

@ Karl: that really looks professional! Congrats!

I need your experience about putting the LEDs + heatsinks INSIDE terraria.

I will put most of them outside, but I'd like to have a strong light for my Heliamphoras. I thought about putting a few LEDs just above them. In addition, this will provide some heat, since it's quite cold in winter in the room where my highland terrarium is. Perfect for the nights, but no ideal during the days.

My idea is to put some kind of silicone (the one used for seals in bathrooms) over solders and electronice parts in order to avoid moisture to reach them. Any thought/recommendation about that? Or any other idea to ensure the humidity will not create a mess...

[Peabody]

Vincent,

Have you got your LED lights yet ? If you are planning on making them yourself you could consider having a look on ebay for clear plastic tube - you could slide your lamps down the tube and have the ends of the tube outside your terrarium with the tube on the inside. The electronics would then be isolated from the humidity. A small fan blowing through the tube would provide some cooling. I think even a relatively small wattage LED system would overheat the terrarium if if was entirely inside.

(I have done a crude experiment with a power resistor being fed with 12 volts at 350 mA - that's about 4 Watts. It warmed up the air in a polystyrene fish mongers box to about 6C above ambient room temperature. The box was about 3/4 cubic foot.)

[Prompt]

I use LEDs without protection with humidity around 80%, it never happened a problem.

From my experience, the moisture in the air does not create any problem to the electronics, while the condensate is more insidious. The LEDs still operate at low voltage, and then pure water and moisture do not create damage. If the water is rich in salts, then the question changes.

Prompt

[vincent]

OK, thanks for the answers.

@Peabody: that's a good idea, but my aim is to avoid fan.

@ Prompt: OK, that's good to know. But I'll have at least some of the LEDs close to the ground, and they could receive some water when watering. So I will have to protect at least some without affecting the air movements around the heatsink (so covering the module is not possible, otherwise the convection around the heatsink will be decreased and the LED temperature will rise).

Anybody tried to protect LED with silicon or similar?

[Prompt]

It is sufficient that cover only the contacts with silicone or with varnish or nail enamel.

For the body of the LED does not need any protection.

Prompt

[pmatil]

In my opinion leds in terrariums need to be protected from the humidity somehow. Personally I coated the electronic parts with acryl varnish (i.e. car clearcoat). The only thing I didn't cover with it was the leds' lenses. Silicone is fine but I wouldn't use aquarium silicone or similar as the acid may damage the electronics (there are specific types of silicone for electronics protection).

[vincent]

I'm getting crazy!

I can't find such non-corrosive silicone in Geneva...

Does anybody know a place where to buy this online?

Or do you have the name of a product?

[pmatil]

Just found out about a silicone gel that is suitable for electronics. It may be a little thin because it's for potting purposes. It's called QSIL216 silicone encapsulant and I've seen it on ebay. I'm maybe ordering it soon.

[vincent]

OK, now it's my turn to show you my LED set-up (THANKS to Prompt and The body snatcher pod for the interesting discussions that helped me to choose the components).

My aim was to build something quite powerful, with some flexibility. This is why I choose to have some independent LED-heatsink modules that can be moved very easily in order to manage the light intensity over the different parts of the terrarium.

LEDs: mix 1:1 of the following, mounted in series (bought here: http://www.led-tech.de/):

- Cree XML2 U2 Bin 1C, Kelvin min.: 6000, Kelvin max.: 6500

- Cree XML2 T3 Bin 7B4, Kelvin min.: 2900, Kelvin max.: 3300

Driver: 70W - 2100mA (http://www.aliexpres...1089848638.html)

Heat sinks: http://www.aliexpres.../707020241.html

Lenses (http://www.aliexpres...1306093305.html): 45° over Nepenthes and orchids to maximise the overlap between cold and warm white. 30° over Heliamphoras to maximise light intensity. The lenses are place over the glass of the ceiling of the terrarium. No space between lense and glass, to avoid accumulation of dust. The heatsinks are stabilised with 3 screws in order to maximise the airflow that cools the "wings" and thus keep the LEDs not too hot. I choose this kind of heatsink because they have vertical "wings" and the air can flow freely due to the convection.

LEDs glued to heatsinks with Heat Conductive Glue Arctic Silver.

The wires are still a bit messy, but it's only the first day. I'll clean that after the test phase.

I also added 2x 10W red/blue LEDs light over the Heliamphoras to increase the intensity. (http://www.aliexpres.../608060401.html)

Pictures taken from inside the terrarium:

[jp]

Your setup seem to be very good, bravo!

Can yo tell me how you have you stick the lense to the led ?

by jp.

[vincent]

Salut jp, Merci pour le commentaire. :-)

Actually, I did not have to stick the lenses to the LEDs, because I've set-up the distance between the heatsinks and the ceiling of the terrarium to be exactly the height of the lenses. This is why I used the 3 screws per heatsinks in order to be able to have a very precise adjustment.

The LEDs are slightly inserted in the lenses, so they can't move laterally.

[Adelae]

I'm trialing some solar powered LED's that I have always used in my shed, there are 2 lights, each with 10 small (size of fairy lights) LED bright white bulbs, the trial tank is a 1 foot tank (so they just fit) the plants are D.Spathulata (seed), D.Burmannii (plants) and U.Livida, the only reason is they are common enough plant for me.

So far these lights get 4-6hours run time (any longer and they dim and time varies on cloud cover), they are 10cm from the plants.

The tank will also be getting some bright light through a window, but no full sun but 3 side have reflectors.

If the plants are alive after 3 months I will let people know and post some pics.

Now a question, I have been told that plants need a dark period to survive, so if a light system was running all day and night would the plant live ?

[Guest paul y]

lots of plants can be grown under 24 hrs of light, most plants flowering time or dormancy is initiated by changes in the photoperiod however, plants photoperiod is largely dictated by their natural range, the closer to the equator a plant originates the more its need for a 12/12 photoperiod, the closer to the poles the longer the photoperiod, the further north or south you go the longer the day or night respective to winter or summer.

I have never grown cps under 24 hrs light, the only reason to do so is to force as much vegetative growth in a short a time as possible,

long term 24 hr photoperiod will most likely be fatal to most cps.

[CephFan]

Morning All,

I have always used fluorescent tubes in my terraria but was interested in the possibility of a low energy cutting/seedling box. Vincent's tank is amazing but it is pretty tall so the high power system works for that.

Has anyone here tried one of the 15w red/ blue 225 LED panels that are easily available? I know the coloured lighting looks odd but it would purely be for propagation at a height of 30cm or less.

Cheers,

Steve

[Peabody]

Hope the pic of my polystyrene fishbox propagator is visible. It has two 8 Watt electric seed trays controlled by a thermostat. The (12 Watt) LED lamp is resting on a sheet of clear plastic.

The target temperature set by the thermostat is 25C but when I took the photo I only had one electric seed tray and it could not get upto temperature. The seeds I am growing are in a plastic biscuit box sitting on top of the two seed trays.

[CephFan]

Ok thanks Peabody,

So that's 12W in a small tank so if it works for you I should trust the 15W lamp for a small growth chamber.

Cheers,

Steve

[vincent]

Just a little update about my terrarium, and time for the first conclusions. I have to say I very happy about the results, given that the overall power is 70W of my LEDs + 2x10W of blue/red LED lamps over the Heliamphoras. So 90W in total.

LEDs connected in a little bit cleaner way:



N. ovata (top), macrophylla (left) and hamata (right). The colors look OK to me.

 

H. neblinae. As you can guess, the pitcher that just grew under the LEDs is the bigger one. the 2 green ones were grown before the LEDs system was implemented. The other ones were grown last summer, when the plant was in the sun.

Edited April 12, 2014 by vincent

[Hud357]

Sorry for the lateness to the thread (then again it looks to have been glowing for years)

 

Vincent, that's a really nice setup.

 

I'm currently looking at LED's but I'm having a bit of trouble seeing the advantages, apart from flexibility (see vincent photo's above) ..

 

• Although LED's have a better heat/light ratio. Is that change significant enough to warrant an expensive change from std. lighting?

 

• A lot of issue has been made of EM output in various bands. Would this (true or not) have any noticable effect on my plants outside the lab?

 

• There is a trade off when it comes to 'off the shelf' v 'home cooking'. Perhaps this will change as time passes but currently one is either 'home brewing' or buying 'off the shelf'. An important consideration.

 

• Many (LED experimenters) will have noticed that getting rid of 'point source' heat is more problematic than with other lighting systems. LED's are not so efficient that they produce no heat - quite the opposite.

 

 

Anyway, apart from the obvious flexibility of LED lighting, could we have some discussion re their other merits?

 

Edited June 11, 2014 by Hud357

[Prompt]

Some of the advantages of LEDs are:

equal lumens consume about half of the current of other lamps

not require reflectors because the cone of light is about 140/150 degrees

the distance from the plants can vary, just add or remove additional lenses

The cost of a 10-watt LED is now less than a CFL lamp

The brightness can be adjusted according to the needs

The supply voltage is low voltage and is not dangerous

The light emitted is devoid of heat, the only heat emitted is on the opposite face of the light beam

their brightness decreases over time (we're talking 50 years and older)

The disadvantages are:

require an electronic driver (only for power LED)

require a heatsink

the spectrum of white light, not cover all the frequencies

I hope I have been of help to your reflections

Ciao

Prompt

Edited June 13, 2014 by Prompt

[vincent]

Hi,

Just a few pics to show how my plants are doing under my LED set-up (no direct sun at all)

 

 

 

 

 

The Nepenthes part of the terra is going great. Look at this nice (but not focused, shame on me) jamban pitcher in the middle-bottom part of the pic.

However, the Heliamphora part is OK but could be improved. I've just moved the LEDs over that part to increase the intensity. It should help.

[pmatil]

I have just completed a new LED lighting fixture for my other terrarium. The LEDs are (from left to right): RED, WHITE, BLUE, RED, WHITE, RED, BLUE, WHITE, RED. The reds are 660 nm, blues 452 nm, and whites 6500 K. The power for each color (and red for left part and for right part) is adjustable from 5% to 95 %.

 

Electrical power is about 33 W max. (input). LED's are 5 W max. each except whites who are 3 W max each. Electronics use PT4115 controller with self-made circuit boards. The power controlling part uses 555s for the PWM control. The fan is on constantly at 5 V (12 V fan) although the fan is only needed at full power.

 

Edited July 1, 2014 by pmatil