Quote Originally Posted by SaltyJim View Post
Why would you compare the 10k AB to the 20k XM. Wouldn't 10k to 10k be more relevant? According to the same site, the XM has an efficiency of .3755, and a higher PPFD than the AB, so why not that one?
But they're more blueeeeeeeeeeeeee!!! The spectrum is more towards 13k than 10k, which ultimately it was my deciding factor. There are better bulbs than the XMs even, but hellolights doesn't carry them. :( I am just glad to have the extra PAR. I have been needing it!