More T5 Florescent Questions

[Rootsnleaves]

Hi,
I am new to the forum but promise I did use search extensively before posting.

I have a 4 bulb T5 fixture, with two 3k and 2 6.5k bulbs. I have had it for 9 months, and have had good results in terms of foliage and root growth. I have also bloomed a phal. dendrobium, which is an accomplishment as my Forum Name indicates.

Based on old posts, I think it is time to replace the bulbs. My question has to do with what combination I should use.

1. Keep the current configuration.

2. Go to 3 3k and 1 6.5k to increase chances of blooming

3. Use 4 5k "Sunlight" bulbs to split the difference.

By the way, those of you who are paying a lot for your T5 bulbs should check out Great Lights 4 Less on Ebay. The high output bulbs are between $22 - $25 FOR FOUR BULBS. Shipping is an extra $16, but that still makes it less than $11 per bulb.

Thanks for your help.

[Ross]

I use 3 - 6500K along with 1 - 3000K. The reason for this balance is to try to maintain 5000K (or close to that) as this is color temp of daylight, full sun at equator.

T5 lamps should go 12 months before any degrading.

[Rootsnleaves]

Ross,

Thanks for your reply. First of all, great news that I can wait a few more months.

Secondly, if 5000k is the goal, shouldn't the newer 5000k lamps provide that, eliminating the need to mix 3000's and 6500's?

[Ross]

Yes

[limxuanhong]

Hi there, do you use cool daylight or warm light with a reddish hue?

[Rootsnleaves]

There have been much better explanations in other threads on the board to this question, but the quick answer is that the 6500k bulbs emit more in the blue/white spectrum and the 3000k bulbs emphasize the red end of the spectrum. So, I am currently using both types, but will probably switch to a full (balanced) spectrum 5000k when I replace my bulbs.