T5 Bulbs

Tybo

Tybo

Time to buy some new bulbs for my fixtures.  I walked by my grow shelves a while ago and noticed that things looked dimmer than earlier today.  Sure enough I have 1 bulb out and in another fixture a very dim bulb.  What I have is T5HO 48" 54 watt 6500K bulbs.  The fixtures are 4 bulbs each. 
Does anyone have any suggestions on changing up?  Mixing different K values?  I wonder sometimes if what I have isn't too bright.  I have noticed some of the seedlings sometimes curling up their leaves.  After spending the night in the darkness, they perk up again so I assume (yeah I know what they say about 'assuming') that the light were just too much for them.  
The temperature under the bulbs isn't excessive and the height of the bulbs above the seedlings is about 16".  
Any suggestions?
Thanks
 
Hey Tybo.  I often mix in the 2700K bulbs, myself.  I also tend not to run 4 bulbs in a 4 x 54w T5HO fixture.  One of my favorite mixes is a 6500K in each outside slot and a 2700K bulb in one of the middle slots, with the other empty.  I see people get great results running all 4 at 216w, but sometimes I get environmental issues running a full mix.  I do move the lights in closer with lower wattage.
 
Thanks for the info, CD.  I'll have to go shopping.  I did a quick search online at one of our local big box stores and didnt see 2700k but they had 3000k.  I'll look around.
 
In my ghetto T5HO fixture I run 6 @ 6500K, 4 @ Full Spectrum +UV, and two Actinic blue.
 
I have three timers, each controlling one four lamp ballast.
 
One period is 5AM- 9PM (16 hours) 4 @ 6500K
 
Second period is 6AM- 8PM (14 hours) 2 @ 6500K, 2 @ FS +UV
 
Third period is 7AM- 7PM (12 hours) 2 @ FS +UV, Actinic.
 
Here's some pics of the seedlings that make me think the lights are too much.  It might be something else but I don't know what at this point.  I make sure to give them water so they don't dry out.  Actually I've been giving them 1/4 strength nutes.  DynaGro Foilage Pro.
 
First pic is a Wiri Wiri.  Not looking too good compared to my other seedlings.
CH4LpUr.jpg

 
Here's a sugar rush stripey in the same shape:
gAHvmfU.jpg

Last is this Piri Piri.  Ive already lost one.  Hate to lose this one.
sSeJe3N.jpg

 
 
 
Some of them do look like they're having transpiration issues.  Possibly a bit of too much too soon with the lights - ?  With the ones that seem especially affected, sometimes that can happen when the roots are slower to develop after germination for whatever reason.  Have you considered moving the harder-hit ones into a semi-lit area to reduce the stress on them while they root in a bit?
 
EDIT:  On the subject of alternative/supplemental spectrum bulbs, one of the reasons I like having the 2700K bulbs available is that I've read that general spectrum of light is favorable to root development in seedlings.  I suppose the theory might be that in the early and late season the natural light reaching the plants is more toward the warmer end so they favor that light for getting started and producing, versus a cooler spectrum during their main growth phase when the sun's light is traveling through less atmosphere to scatter blue light.  The 2700K's also seem a bit less intense than the 6500K bulb, too, so perhaps less stressful.  Right now I have a row of my earliest sprouts under a single bulb of T5HO 2700K, but after they get going a bit I'll start filling out the fixture with 6500K. 
 
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