Metal Halide/High Pressure Sodium Lights

[drosera]

Hi,

I'm slowly thinking about the dormancy period of my plants, in particular, my collection of Sarrs. I had some limited success leaving them on a sunny but cold windowsill last year, but when the time came for some fairly active growth (in Feb.), the sun's orientation had changed, leaving them without adequate light. Being in a ground floor app., I had no other suitably sunny window at that time of year.

I'm considering getting MH or HPS lights, and setting them up in a large closet. I would fabricate some kind of temporary cover or terrarium to house the plants.

This would be my first time using such lights, and would appreciate any tips from someone who has used them before. I realize heat and humidity will be concerns, but what else should I need to know? How far away should the plants be from the lights? And just out of curiosity, could fluorescents be setup to do the trick?

The whole thing would only be necessary for a couple of months, until I can start putting the plants outside.

Thanks.

Chris f.

 

[Shauntell]

I have never used these lights myself but from what I've heard they use a lot of electricity and give off more heat. Those were the reasons that I decided not to use them. They are also more expensive. I would not personally go with them but that is just me and I have a very small setup. These lights are for growers with a lot of plants. If you have a lot of plants then they be jsut the thing for you.

 

[ccrider1016]

i dont know if this will relate to this, but here goes, i used to run large saltwater reef aquariums here at home, i got to know a lot, and i mean a lot! of petshop owners, and i did a lot of reading too, through all of this, everyone that used metal halides, used 2 diff kinds mostly, and expensive too. there was a smaller setup, then the double setups( 2 of the smaller ones united as one unit). EVERYone that used these setups had to use a cooling system for the tanks( mind you now, these lights would sit pretty high above the water now), cause the water would heat up very fast. now, think about this, the plants arent in water to cool them, they live in the air, so the only way to hook em up i think would be to hook up a cooling system to the lights, to diffuse the heat( which the lights get very, very hot to the touch, burn hot! these lights were enclosed in metal, and glass, and they still produce this much heat, if you have a green house, and want added lighting, then go for it, but in the house, not a good idea, unless you have a cooling system for it. thats about all i can say to these lights, very good output, and toooo much heat.


ccrider

 

[Martin]

Hello,

I'm illuminating my highland terrarium (120*60*85cm) with a 70 W high pressure sodium lamp (it also gets some sun from an East facing window).
The coloration of Heliamphora is excellent, the lids are almost as big as in natural habitat. Nepenthes are standing at the darker corners of the terrarium.
The temperature raises about 2°C if the light is on. It would be very nice if the temperature would raise even higher, so I needn't use additional heating.

Last winter I also used a 250W high pressure sodium bulb for a 2-3 hours additional lightning of tuberous Drosera and Roridula during the winter months. The plants where standing on a south facing windowsill and temperature increased not more than 2°C if the light was on. (the room's dimension is 5m * 5m)

I sold this lamp because I wanted 8 hours of additional artificial light a day and 250W would be to much for a less than 1m² area. And the electrical bill was to high, too. I also don't like the yellowish colour of the high pressure sodium lights in my living room.

So I switched to metal halide lamps with 70W. I will install two of them, one running from 9.00 am to 12.00 am the other one running from 11.00 am to 5.00 pm. Sun (if it shines!) is hitting the plants from around 12.00am to 3.00 pm.

There are different models of metal halide lamps.
The best ones with 70W give you 6000 lumens (Phillips CDM 942) with an excellent spectrum (light quality 1A, very similar to sunlight) or 6500 lumens (Phillips CDM 930) with a slightly worse spectrum (1B).
Don't use HQL lamps with around 3000-4000 lumens which are often offered as aquarium/terrarium lamps but are not good.

If the lamps are not inside the terrarium there is absolutly no problem with warming up. I even would like more warming up from the lamp to immitate a better and more natural temperature shift between day and night.

Martin

Btw : The 70 W high pressure sodium light gives you around 6500 lumen.

PS : a very interesting site for artificial lights spectrum and efficienty is http://www.hereinspaziert.de/Sehlicht/wuchslicht3.htm
(it's in German)
LL means flouresent lights (different colors), GroLux is a special flouresent light disigned for plants
HPL,CDM, MHW,MHN are metal halide types
Son-T is high pressure sodium (note that a 400 W is much more efficient than a 70W. (400 w = 138 lumen/W, 70 W = 95 lumen/W)
aquarelle is a special aquarium lamp which is very "blue" (10000 K)

Some Helis growing under my 70 W high pressure sodium lights...

Heliamphora ionasii :

Heliamphora heterodoxa :