Lighting for seedlings.

[Hotwired]

Anne... Remember that when you see a red object it is because that wavelength is being reflected back toward the eye, meaning it does not pass through the plastic. I would imagine that your red dome reflects AND transmits red, but absorbs all the other wavelengths. Either way, a colored dome is not desirable. Light is Absorbed, Reflected, and Transmitted. Leaves appear green because that's a wavelength that they use very little of and reflect it.

All plants need Blue and Red light. For Foliage, they need much more Blue light than Red, and vice-versa for Flowering. You would think that a red lens (dome) would add more red light. You can never get more light in any wavelength than the source creates. It appears to be redder because you have blocked much of the other wavelengths. Clear is always better because you want to maximize the lumens reaching your seedlings.

I have spectral curves for all the major growlight bulbs. I may post my study results along with the data when I get a chance.

[aclum]

Hotwired,

Thanks for the rapid and very helpful response!! (Fortunately they were out of the trays with the red domes when we went looking for them today LOL!) Will be on the lookout for some clear domes now.

Anne