Buying some new lights and still debating between 2 100w COB lights and a 315w CMH. I have a 3x4 grow space and I typically only run two plants at a time. Grows are either soil with a Scrog or hydro with a four way topping and tying down. Any input/experiences on which way to go would be appreciated.
I grew a considerable amount with various LED fixtures (including ordinary LED household lightbulbs[1]). They definitely work. But, I didn't feel the finish quality was as good. (Crystals, aroma.). My product was kind of dry (not sticky, resiny. It was still good. If I hadn't grown with T5HO before using LED, I wouldn't have been very impressed.). I think it's because LED doesn't have UV like traditional lights. I used Reptile CFL bulbs for UV. But, that's a hassle. I never knew how much to use, how long, the lifespan of the bulbs.
I ended up liking T5HO at 40w/sq ft (45 in flower, with some LED household bulbs as sidelighting). And, CMH at 35w/sq ft (38 counting the ballast. And, again maybe supplementing with sidelighting in late flower.).
I produced a ton of dense bud using household bulbs at 28-32w/sq ft. And, there are high-quality LED fixtures that will produce at 22-25w/sq ft. The problem is, it's hard to find objective info about LED fixtures. There's a *ton* of flim-flam out there, selling for high prices. And, people who own it will defend it till the death. So, you can't go by testimonials. It's very religious. People will say "I love my [fill in the blank]." But, they won't provide objective info about w/sq ft, or the finish quality. (One guy was growing *amazing* buds under one scammy brand. He loved it. Everyone was justifiably drooling over the buds. But, nobody talked about how he was using 80w/sq ft! That's more than HPS! That's the kind of thing I saw *a lot* of. Nobody started from the proposition: "why do I need LED." They just got into it because it's the new-fangled thing. And then set about making it work -- with more light. The more they went down that path, the more defensive they were, evangalizing, etc.).
I didn't like anything about the LED scene, to be honest. Predatory sellers. Religious-minded buyers. Flame wars. Everyone with a hair-trigger to defend their "denomination." Very little was objective. It's a tough issue because, if someone likes running [fill in the blank] at 40-50w/sq ft, who cares? Part of growing is having fun. But, when someone is considering buying LED.... it was impossible to have rational discussions. (If it involved a sponsor of a forum, you could get banned.).
IMO, the only reason to use LED is if you live in a hot climate (or have expensive electricity). But, you'll have to spend a lot of money on high-end fixtures. The average stuff won't run cooler than CMH or T5HO. You'll probably have to run the average stuff at more w/sq ft. (Also, CMH has remote ballasts now. And, air-cooled hoods are available. It's also possible to replace the ballasts in T5HO fixtures with remote-mount ballasts. I can give more info about that. Or, call Fulham to discuss it.).
To me, traditional componetized/commoditized lights are better. No secret-sauce "spectrum." No drama. No team sports. I still use LED lightbulbs around the sides of the tent of sidelighting. I think LED lightbulbs are great for new growers. They can start small until they know they can grow. They don't have to go "all in" on a light fixture. And, whatever they buy can end up being used for sidelighting. It's not a dead-end.
[1] I hope it's ok to link to another forum. This is where I posted some info about my lightbulb grow, just so you can see how well it did. It just wasnt' top-shelf.
https://www.thcfarmer.com/threads/cob-vs-the-gram-per-watt-rule.104876/#post-2268754
