Is my HPS setup appropriate for Orchids?

[demosthones]

I'm VERY new to growing Orchids. I want to try a few trial Orchids and then really start finding exotic and rare strains/phenotypes.

I will probably set up a grow tent just for orchids in a few months, but right now I have a vegetable grow set up in a 3.5' X 3.5' closet. Here are the specs.

400 watt HPS (Just regular low kelvin HPS, I don't have any enhanced spectrum bulbs at the moment, but I could look into it.) This light puts out 55,000 lumens spread out over about 12 square feet (~4500 lumens per sf). I could probably find periphery areas of my grow room with lower light levels (although I don't have a light meter yet.)

My temperatures this time of year run between 58F low - 78F High. Is the low temperature going to be an issue with most Orchid strains? (When I set up my grow tent it should be a lot easier to control the temperature.)

RH is between 45% - 60%.

Currently I'm running lights 12 hours and dark 12 hours. I could vary this slightly, but wouldn't want to go more than 13 hours light (in this room.)

If this isn't sufficient I could put a few orchids in a shelf in my closet under a single 2' t5 HO blue spectrum light (Thinking it puts out like 2200 lumens, but not sure off the top of my head.)

I'd appreciate some advise. I'm really new at this, so forgive my ignorance.

Demosthones

[Ross]

Originally Posted by demosthones

I'm VERY new to growing Orchids. I want to try a few trial Orchids and then really start finding exotic and rare strains/phenotypes.

I will probably set up a grow tent just for orchids in a few months, but right now I have a vegetable grow set up in a 3.5' X 3.5' closet. Here are the specs.

400 watt HPS (Just regular low kelvin HPS, I don't have any enhanced spectrum bulbs at the moment, but I could look into it.) This light puts out 55,000 lumens spread out over about 12 square feet (~4500 lumens per sf). I could probably find periphery areas of my grow room with lower light levels (although I don't have a light meter yet.)

My temperatures this time of year run between 58F low - 78F High. Is the low temperature going to be an issue with most Orchid strains? (When I set up my grow tent it should be a lot easier to control the temperature.)

RH is between 45% - 60%.

Currently I'm running lights 12 hours and dark 12 hours. I could vary this slightly, but wouldn't want to go more than 13 hours light (in this room.)

If this isn't sufficient I could put a few orchids in a shelf in my closet under a single 2' t5 HO blue spectrum light (Thinking it puts out like 2200 lumens, but not sure off the top of my head.)

I'd appreciate some advise. I'm really new at this, so forgive my ignorance.

Demosthones

I already posted to your other posting, but this one asks some very specific questions I may be able to help with.

I really don't think you need something like a "grow tent" although that certainly wouldn't hurt. There are lots of pretty tolerant orchids that don't actually need the high humidity. Certainly humidity over 70% is ideal, but my grow area dips to less than 30% occasionally and I rarely have a problem with the more common types. I do with some of the difficult to grow species like Sedira, but there are ways around that (like a wardian case.)

The lumens you mention at that distance are a bit weak for most of the orchid types except perhaps for Phalenopsis or slipper orchids. The 12 hours on/off would be fine. I personally increase my on cycle during summer months because I have such a varied collection and a few respond to day length changes. My personal recommendation would be to skip the tent and go with a bank of t5 florescents balanced for 5000K or close. It would be plenty of light, it would be cheap to run (a bit over 200 watts), cooler to run (especially in summer or an enclosed space), better light distribution over the Kelvin range, etc. You could literally set up a table in a room, hange such a fixture from the ceiling, place it on a timer, use the "Sun Lift" hanger system which allows for easy height adjustment, setup a drip pan system to catch drips from watering, and you're good to go. Under such a system you could easily grow Phals, Paphs, Phrags, many Oncidium-based intergeneric crosses, a few Encyclias, and lots that I don't grow, so have no knowledge. Have fun with this, sounds like you're pretty-much ready to go. PM me if you have specific questions that don't relate to this posting.

[demosthones]

Thank you very much Ross.

Do you mean that the t5s actually put out more lumens than my HPS? I understand that 200 watts of t5 light would put out significantly less light than 400 watts of HPS. However, I could see that the kelvin rating would be better and CRI would be much better (although I don't really understand the significance of CRI yet.)

I guess I'll just pick up a few cheap varieties locally to experiment with at different distances from the light.

I'll hold off on the tent for now and see how things go.

Demosthones

[Ross]

Your question can only be answered with a light meter such as I suggested (a high quality one.) I gave you the foot candle measurements on my t5 setup? At lamps its over 2000 FCs. At 10-12" its 1900 foot candles. Formula for lumens to candle power is divide lumens by 12.57. I think that is candle power over 1 foot area, but not sure. Light meter is best way for all of us to be on same page. The one I suggested reads both Lux and Foot-candles, so you can even converse with Europeans who don't use foot-candles.

[demosthones]

Sounds great. I'll start looking harder for a light meter. I've been wanting to use one anyway. I'm on the same page as the Europeans because I haven't used foot candles before either But I'll find out how.

Demosthones

EDIT:

I found this formula through a google search.

footcandles (lumens/square foot) x 10.764 = lux (lumens/square meter)

I'll plug in my numbers.... footcandles (55,000/12) x 10.764 = lux (lumens/square meter)
4583.33 X 10.764
lux = 49336

That doesn't really mean anything to me, but might mean something to someone else.

[Ross]

Get the one I suggested (Lux meter) and you won't have to. Lux is the standard anyways.