Lighting for my new orchidarium - enough or too much?

[s1214215]

Hi Everyone

I am getting an orchidarium made out of wood with low iron (Diamant) glass to allow maximum light through. It will be 40 to 43 inch tall by 51 inch long by 28 inch front to back.

I am a little confused about my light output and need some assistance. I already have 2 x 4 (54 Watt) tube DE T5 light units with individual parabolic reflectors over each tube. I can get Sylvania Growlux tubes which I think are rated for 8500k. I dont really want metal halides.

My question is what will I be able to grow with this lighting. Is it too much or not enough for low light orchids at the bottom and high light needs at the top? I will raise pots off the base of the orchidarium with eggcrate shelving.

Many thanks

Brett

[s1214215]

I forgot to mention I am thinking of putting a mirror on the back of the orchidarium for more light reflection.

Brett

[Ross]

Do I understand you have 8 tubes total? If so you can expect 30,000 lux (3000 FCs) near the top of the tank and maybe 500-750 at the floor of the tank. This allows for quite a range of plants. What are you interested in growing?

[s1214215]

Hi Ross

Thanks for the reply.

Yes I have 8 54 watt tubes in total with a reflector on each. According to the manufacturer it improves the amount of light directed down more than one reflector for the whole lot. The units are made for marine aquariums which are very light intensive.

I am not sure as yet what I will keep. I will move back to Australia next July to Melbourne and I will need to see what the climate is like. I know they can grow masdevallias, odontoglossum alliance there as well as the more cool tolerant catts and vandaceous in shade houses.

At this time I need to make sure of what lighting I will use. I was not sure if T5 would be strong enough given the depth of the orchidarium. But from what you suggest, I might be ok for higher light need orchids at the top and low lighters at the base.

How much light would be the maximum high light orchids could take at the top? Would adding another 2 tubes be too much light at the top if the light level is too low at the bottom?

Many thanks

Brett

[Ross]

Originally Posted by s1214215

Hi Ross

Thanks for the reply.

Yes I have 8 54 watt tubes in total with a reflector on each. According to the manufacturer it improves the amount of light directed down more than one reflector for the whole lot. The units are made for marine aquariums which are very light intensive.

I am not sure as yet what I will keep. I will move back to Australia next July to Melbourne and I will need to see what the climate is like. I know they can grow masdevallias, odontoglossum alliance there as well as the more cool tolerant catts and vandaceous in shade houses.

At this time I need to make sure of what lighting I will use. I was not sure if T5 would be strong enough given the depth of the orchidarium. But from what you suggest, I might be ok for higher light need orchids at the top and low lighters at the base.

How much light would be the maximum high light orchids could take at the top? Would adding another 2 tubes be too much light at the top if the light level is too low at the bottom?

Many thanks

Brett

Well, I certainly can addres the light output. I measured, recently, 3600 foot-candles (36000 lux) at approx 18" (I think) from the tubes. This is with a dedicated 8 tube fixture. The problem with 8 individual tubes is the light spread will be different. I would get a met (if you don't have one) and measure your available light. I still think you'll be in the high 3000 FCs output. Now this should be fine for most Cats, Mini Cats, Phals, Encyclias, Paphs, etc. depending on the distance from the tubes. adding more light light at top won't help at bottom since light falls off at square of distance from source. This means that if light is sufficient at top of tank, it is dismal at bottom. Need to switch species.

[s1214215]

Hi Ross

I will get a light meter. I think when I get the orchidarium made I will allow enough room for metal halides just in case the T5s turn out to not be strong enough to light the bottom sufficiently. I have them for a marine tank actually, but I want to try them out on my orchidarium first and see if the light is strong enough.

If they fail to be sufficient, how many watts of metal halide would you suggest for low light species such as paphs, masdevallias, sarcochilus etc at the bottom?

Many thanks

Brett

[Ross]

I don't know the translation for metal halide lights, but you should be seeking approx 2000 FCs at the leaf surface of those species. Since you have seperate fixtures, can you move part of them to the outside back down near the bottom? Just aim them horizontally instead of vertical. Since it's a custom design, maybe an alcove at the bottom back for two of the tubes? Six at the top should be fine. I use a 4-tube combined fixture on mine and the width from front to back is approx 20". I read a constant 1800-1900 foot candles at 8" across the width of the tank. For me, that works fine. Your six tubes should equate to perhaps 2700+ foot candles which should be fine for most Cats, or equiv.

[s1214215]

Hi Ross

Thanks for the advice.

Sorry, I forgot that metal halide is HQI in the USA - I think... I think we get them in 75w, 150w, 250, 400w, and 1000w here. I am guessing no more than 150 would do with 2 units.

Anyway, my T5 lights are 2 x 4 tube units. It is only the reflectors that are individual. I will try them at the top, but get the carpenter to leave enough room in the canopy for HQI/MH lights if not enough. I will get a light meter too before I finalise the set up.

Thanks again

Brett

[Ross]

Originally Posted by s1214215

I will get a light meter too before I finalise the set up.
Brett

Brett, since you have the lights now, can you set them up and mock up a similar temp. enclosure and meter the light? You could adjust height or other measurements that way before your builder is finalized.

[s1214215]

Hi Ross

I thought of that too. The only thing I dont have is the correct tubes. The ones I have are the wrong kelvin. 12k and 14.5k for a marine tank.

I am making the orchidarium here in Bangkok as it is still cheaper to make here and ship back with my other stuff than make in Australia. Knowing about the approximate ability of my T5 lights was just to help me with my orchidarium design and approximate size.

I am currently thinking it will be better to make the canopy tall enough for the HQI/MH lights any way just to give flexibility. I can suspend the T5 from cables in the canopy ceiling to the correct height. If they do not give enough light at the bottom of the case, then upgrading to HQI/MH will be easy. My T5 five can find a use with my fish in that situation.

I was originally thinking on a canopy just tall enough for the T5. A little more room will look ok and will give me another option if I am not happy with the T5 and need a stronger light source.

Many thanks

Brett