Switch to red or keep both?

Keep both on plant is still using all the spectrum. The sun does not have a veg and bloom. Lol. Happy growing 🌱

From my experience, it depends on what type of lamp you have. Is it a full spectrum lamp that can change it's hue while not losing intensity? Switch to red However, if it's a lamp comprised of many little lamps of different color (like many LED grow lights) intensity > spectrum. By switching off the blue lights, you're simply robbing your plant of extra light. It might not use as much of the blue as before, but it's still helpful :) Just remember the rule of thumb: intensity trumps spectrum. If your intensity of red light doesn't grow by switching the blue off, don't do it.