Hello newhydro16,
led's have a very short usable distance for plant photosynthesis. The light intensity plants need for photosynthesis is very different than humans need to see with. Sounds like a pretty narrow wavelength range with one specific wavelength (660 nm). The wavelength range for the red spectrum is from about 610 nm to 740 nm, and the blue spectrum ranges from about 425 nm to 520 nm. The green spectrum ranges from 520 nm to 565 nm.
What Wavelength Goes With a Color?
Electromagnetic spectrum
But as long as you already have them see what happens. Even if the LED's give good growth quality, two 45 watt
lights won't be able to grow many plants. If you plan to grow much lettuce you'll need more coverage area and will be much cheaper using florescent lights. If you do get good growth quality from those LED's, they would be good for starting seedlings in a prorogation system. You wouldn't need more than 2 or 3 sq feet for a prorogation system to start seedlings. That way you can rotate new plants into the main system as you harvest. That not only shortens the time the plants need to grow in the main system by 2-4 weeks and makes it much more productive. But also separates the seedlings from the larger plants because the
nutrient strength for seedlings is much lower than for larger plants. If you plan to have a continual supply of lettuce you'll want to start seedlings in a prorogation system and rotate plants anyway.