Needing simple direct answers, please

[try&try77]

Hello

" i need the goods, the straight goods, and nothing else".. Johnny Dep, Fear and Loathing

I have been going around in circles with this whole indoor lighting "stuff".. from full spectrum, to Kelvins, to CRI's.. from T5's to old school T12's

I don't mean to come off as being rude at all!! ( frustrated yes, rude, no)

I bought a 24" Sunburst T5, basically F24T5, at $35.. (which is basically a 24" cabinet light, with a small ballast inside to run a 24W T5)

Now, I have found a specialty sign lighting place that selling F24T5 .. that come in 3000K, 4100K, 5000K, 5600K and 6500K that are can come in a CRI between 82 to 93
and the 48" T5's in all the same K as the 24" and the same CRI ratings ( 82 to 93)

A light with a CRI rating of 93 is to bright for most of my orchids and from what i have read, for most orchids.

I don't have a lot of coin to drop on lights, and i will be fabicating my own T5 light set up, ballasts and all, nor do i have the coin to drop on replacing my orchids cause i fried the 8 to 9, i do have,
mostly Phal's (Cloud Temples), a Sherry Baby, and a couple other lower temp. orchids. ( and yes i have done enough electrical to do this safely and properly, thank you all though)

all my orchids are now currently under one 48", 5000K, T10, ( yes a T10) all at different heights, by using empty pots turned upside down.

The Phals seems to be doing ok with the 5000K, but are all just growing leaves and roots, with a temp. during the day at 19 to 21 C, down to 16 to 17 at night, with 11hrs of light everyday

Can someone give me a "very" simple answer as to which K ( 3000K, 4100K, 5000K, 5500K, 6500K with CRI's all within 82 to 86) would work best for vegetative growing part

I also have 4, 24" T5 fixtures. Two of the fixtures are Sunburst 24" tubes ( basically a 24W T5, suppositly with 6500K) in them, and i have 2 more 24" T5 fixtures, with no bulbs in them yet,

but all 4 of my 24", T5's will be for trying to get my orchids to flower/ bloom, the whole fixture lookings something like:

_______1______ ______2_______
6 inches of open growing space in the middle
_______3______ _______4_______ ( all the fixtures will be at the same height, pretty cruel drawing i know..lol)

now, would it be better to go with 2 lower K tubes, say.. 5000K or 4100K in the number(s) 1 and 4 fixtures ( see drawing above ), mostly for the reason that 6500K in all the fixtures would
( and i am guessing now) be to bright for a Phal leafs, which might only be 7" tall in total, where as in, my Sherry Baby foliage already stands at 8", plus..

I hope this makes sense to one of you other fellow orchid growers, that has tried different setups..

[Magnus A]

I do not really now what you are asking for.....

But:

For "Can someone give me a "very" simple answer as to which K ( 3000K, 4100K, 5000K, 5500K, 6500K with CRI's all within 82 to 86) would work best for vegetative growing part" there is no answer! The color temperature and the CRI does not influence growth and flowering in that way! Read this thread for more information: Light for vegetative growth vs flowering? , there is way more parameters that come in for growth and flowering.....

Your statement:
"A light with a CRI rating of 93 is to bright for most of my orchids and from what i have read, for most orchids."

Were have you read this????
The CRI is the color rendering index, it has NOTHING with brightness to do! It is a value that describe how correct you see colors under the light! High value (max 100) give good colors, low value give a distinct color cast. Read : Color rendering index - Wikipedia, the free encyclopedia

To conclude and for some directions.

Aim for high CRI value, this give you true color without color cast from your light.
For color temperature, a pure blue sky has roughly 10000K a normal day with some clouds have something like 5000-7000 K. If you aim for something between 5000-6500 it will be good for your plants!

If you have more direct questions ask them and we will help!
/Magnus

[littlefrog]

I don't know the right answer to your question, but the right answer for your pocketbook is that you can use any old tube you want. I grew great phals and paphs under 8 dollar 4 foot shoplights.

Nowdays for fluorescent lights I use electronic T8 fixtures (under $10 at Walmart) and a rather expensive (for me) tube which is a Phillips bulb with a lower wattage demand (I think 28W) and a fairly good light output - no I can't remember which one specifically, they are at home and I'm at work. They cost about $3 each!!! *grin*

[Aceetobe]

The simple solution to orchids burning is moving them further away from the source of light. This usually means you can grow more orchids, which is typically a good thing. The other solution is simply running the lights for less length of time. (ie 4 hours instead of 10)

Are your plants in a window?

Also many orchids can grow decent vegetation under low light levels, but won't have enough juice to bloom. The color of the leaves will tell you.

If you switch power of lighting rapidly, the orchids won't have a chance to adjust and will burn and die. If you slowly slowly increase the amount of light, they will be fine. If you switch from t10 to t5 start at 1 hour of light twice a day, and slowly ramp it up (1 hour extra of light every 3 days or so). Once you start seeing the leaves dotting purple, you've reached the max amount of light they'll want to have.

[Royal]

Originally Posted by try&try77

Can someone give me a "very" simple answer as to which K ( 3000K, 4100K, 5000K, 5500K, 6500K with CRI's all within 82 to 86) would work best for vegetative growing part

You want the color to average about 5000 - 5500 K. All 5000 or 5500 is fine, so is half 4100 and half 6500. Simple enough?