Well, it was bound to happen eventually - just like building and upgrading PCs, the Gear Acquisition Syndrome has finally kicked in, a year or so after completing the first of my QB120 fixtures. Folks who know me on this forum can probably recall the skepticism I've expressed around "spectrum-tuning", but despite my doubts, I am absolutely open to the idea; hopefully we'll soon see more data on this, as more peeps run the newer products, like the QB96 and the stuff from ChilLED. All that said, I must confess that my main motivation is just the old itch to play around - I'll consider it a bonus if I see measurable, positive results.
So this is what I'm currently working with (times two): 4xQB120s at 3000k, maxing at 250 watts, in a 31"x31" tent. Here's a pic of one of the fixtures, but the two are identical.
View attachment 4222610
The dimensions are 21"x26".
So the first question is: how much 660nm would you add? I've seen recommendations for 8-10% of the total white light, but I don't know if that approach has a strong basis. But using that as a starting point, the first solution that comes to mind would be a single 130 degree QB11 at 20-25 watts, run down the center of the fixture. The biggest problem I see with that is spread. By the end of flower, I have buds practically kissing the 120s, so at that point, the 660nm wouldn't be hitting much of the canopy. (Note to HLG: the size of new far red strips would be perfect, if only I could get them in deep red! They could be attached in a cross formation, but distanced evenly across the light.)
Another option would be individual monos, like those solderless stars. The thing about using those is that I expect I might have to modify my frame by adding little sections of flat bar. I suppose it would be feasible to attach the diodes to the existing frame, but I don't know if doing that would allow me to achieve the optimal spread (though it would have to be better than a single strip run down the center).
Opinions? Suggestions? Corrections? What would you do, and how would you do it?
Thanks, peeps!