Prawn Connery
Well-Known Member
For the QB288 V2 - which uses the same Samsung LM301B LEDs - HLG uses a conversion rate of 68.62. So 60,000 Lux is 874 PPFD.
https://horticulturelightinggroup.com/blogs/news/converting-lux-to-ppfd
The holes were marked on that bit of sheet ally because I was going to mount double row strips to it myself. Looks like a neat job - I like how you're as OCD as I am about building things
I'm thinking 18" is a bit high. I run 120W, but I only have my frames about 12" or less above the plants.
Ideally, you want to find the height that gives you the most even spread of light and then adjust it up or down - as you suggested - with your driver. But don't take measurements from the corners or far edges - measure where you think the tops of the plants will be.
Once you've found a good height, ensure that you don't have to turn the strips up too high to achieve you desired PPFD. If you run the LEDs too hard, you'll just generate excess heat with less efficiency. Better to lower the light a little. Also, you can arrange your plants with the shortest ones in the middle and the tallest ones around the periphery where the light isn't as strong.
Having said that, you should be able to run those four strips at up to 200W or so without issues. I reckon you might find your sweet spot around 150-160W for clones and veg. Just a guess.
https://horticulturelightinggroup.com/blogs/news/converting-lux-to-ppfd
The holes were marked on that bit of sheet ally because I was going to mount double row strips to it myself. Looks like a neat job - I like how you're as OCD as I am about building things
I'm thinking 18" is a bit high. I run 120W, but I only have my frames about 12" or less above the plants.
Ideally, you want to find the height that gives you the most even spread of light and then adjust it up or down - as you suggested - with your driver. But don't take measurements from the corners or far edges - measure where you think the tops of the plants will be.
Once you've found a good height, ensure that you don't have to turn the strips up too high to achieve you desired PPFD. If you run the LEDs too hard, you'll just generate excess heat with less efficiency. Better to lower the light a little. Also, you can arrange your plants with the shortest ones in the middle and the tallest ones around the periphery where the light isn't as strong.
Having said that, you should be able to run those four strips at up to 200W or so without issues. I reckon you might find your sweet spot around 150-160W for clones and veg. Just a guess.
