Your kinda right. More than a number per bar it would depend on the circuit architecture : uv is a 3.5V diode in a circuit which usually totals out around 50V : this is due to driver specs and that generally DC is less dangerous at lower voltage: most legislation s allows you to self certify at these lower voltages. What you get them is 1 uv per diode cluster (4 in this design)
3.5 out of 50 is 7% of power going to uv which is already quite high, so in order to not go overboard on blue/uv and lose yield you need to either add a bunch of red diodes for blue/red balance or use s very warm white with low blue content.
Far red end of day switching is a cool feature, it can shorten the flower cycle but with a caveat: shorten flower cycle can mean less yield. Though you dont need as much as 30min after lights out, maybe 5min.
And no far red for lights on: it turns them to bed, not wake them up - 660 would be more indicated for this.
Difficulty varies wildly with design but generally much easier than youd think. Can you drill an alu profile and put together a frame? Can you push a cable into a pushin connector? Alternatively solder the wiring; which to be honest can be learnt on the go with no previous experience, its that easy. Those are the only real skills need for putting it together.
The difficult thing is making a design that really works well in your space and finding all the gear in a way that you dont get totally bogged down in costs for imports. It will cost you more but if your able to get 100-200 more of value per cycle then those costs are generally fine, you just need to design with that in mind.
Things you can achieve:
- custom spectrum which can change both yield and flavor quality.
- perfect spread: if you look at the last 4 inches towards the walls of a 4x4 its already almost a third of the area: usually light coverage here is poor to regular- if you can improve lightlevels and productivity here even just a little youre already winning. You can either do this thru hardware: adding extra strips on the sides of your bar light. Or you can go another further step: wire all the outer periferral strips together on the same driver to perfectly dial in lightlevels in the centre vrs perifery. You could even wire in side lighting as part of you main light.
Its what i did on this build:
View attachment 16766
Periferrals on its driver
View attachment 16767
Centre on its own
View attachment 16768
Everything on. This build on top of that feature also has one veg and one flower channel, which you can run both at the same time for a higher efficiency full cycle light. If youre running your plants in the same space veg and flower id defo say its preferable to have separate spectrums rather than a middle of the road static fullcycle spectrum.
So a lot of design considerations before you build but once you got the deaign its just a bunch of fairly low difficulty handy work. Though very important to have wore management thought out, its very easy for cabling to become a huge nuisance.
All in all i think its well worth it, if the whole design is all aligned. Youre kind of stacking small benefits on top of eachother: a few % here for better managed spread, a few there for spectrum optimizing yield and shortening flower cycle, a few here cause you can give more light intensity without burning them etc.
Main thing for me still remains that awesome creator feeling: first time it lights up and leaves you blinded with thousands of little dots and then after the first cycle seeing your results improved and beat any of your old lights, its a very different kind of high and extremely addictive.