[StrikeEagle1]

Tried searching but couldn't find a definitive answer....and there may not be one.

What CF straight pin 48" 65watt bulb has the best 'spectrum' for growing plants?

 

[Left C]

I'm sure you know that 65w CF's are ~22" and not 48".

I hope that someone answers your question. I'm curious also.

I just got two of the ADA 36w 8000K CF bulbs. One's in a 2x40w Current. The other bulb in the Current fixture is a 6700K/10,000K. The 6700K part of the bulb looks yellow to the 8000K bulb and the 10,000K part of the bulb looks blue to the 8000K bulb. The 8000K bulb is a crisp white light. It's too bad that ADA doesn't make a 65w or 96w 8000K bulb.

 

[StrikeEagle1]

Ooops, yep meant 22"....I was thinking of the size of my light instead of the bulb size.

I know Kelvin affects how we see the light (i.e. blue, yellow, etc) but I'm trying to figure out which actual bulb (not necessarily tied into a Kelvin rating) has the required wavelengths to promote good plant growth!

 

[bharada]

It'll come down to aesthetics. Anything from 6000-10000K work while still being decent to look at. Less than 6000K and you end up with a distinct orange cast, and above 10000K and it gets to be blue. The exception to this basic rule is the GE AquaRay (9325K) bulb which is a purplish/pink, but the plants do great under them.

I personally like 8800K bulbs, but they're only available in square pin configuration in 65w. On top of that they're not that easy to find now that Hellolights.com doesn't have them in stock.

 

[crazy loaches]

Bulbs designed specifically for plants havent been common yet in CF or even T5. Your best bet is to mix a low kelvin and higher one, like a 6500K and 10,000 or 12,000K. I think the ADA tries to get the perfect inbetween mix with the 8,000ks, though I havent tried them (I have a straight pin setup). Anything in this range should be ok.