----- Original Message ----- From: "Robert H" <robertph3@comcast.net> > plant. I havn't yet found the kelvin to play any role at all. I'm curious about CRI - color rendering index. I can see the obvious difference in what my eyes appear to see at 10k as opposed to 6.7k. I understand, I think, that much of this is due to the phospers that different bulbs use (in that some bulbs have a lower cri rating than others). I assume it is important to select bulbs with a high CRI. Does it necessarily follow that high CRI gives you a closer approximation to "true color", whatever that may mean? If 6.xk approximates (to a plant) noon day sun, and 5.xk mid-morning, that would mean that our plants are always, when lights on, in either mid-morning or noon sun. Does this need to be taken into account in terms of dosing, hours, algae control, etc.. or am I overcomplicating? -d ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/