Thanks John for the kind words. Since I first wrote this article I have been changing the combinations and noting the affects on the plants. Currently I'm running 2x Osram 840 and 2x Osram 880. This I find gives me great pearling and plant colour without too much green. If you like more green the swapping the Osram 880's for Philip's 965's works well. To save money you could even use Osram 865's instead of the Philip's 965's.
James
James