I plant cactus indoor under fluorescence light.
I use mix light, three normal 'daylight' 6500K tubes which rich in blue spectrum, so I add a pure red light tube to supplement the red spectrum. I calculate total light intensity is approx 10,000 lux. Nearly 20% of direct sun light. I supply light 16 hours a day.
After few weeks, I suspect that the red spectrum burn some of my cactus. But I continue the test. After nearly two months, I certainly sure that the intensive red spectrum can burn most cactus to death. I sure that they did not died from heat. Because only side of skin that expose direct to the red tube were burnt.
Some interesthing that I found.
Euphobia are more sensitive to the red light than cacti. They burnt to death first. Most cactus grew and produce significant longer thorn. But in the longer time their older skin was burnt. All furry cactus produce longer hair and survive.
Intensive red light can kill cactus
I had a similar experience with a red heat lamp and a echinocactus grusonni in my son's lizard cage. I wasn't sure if it was the light spectrum, the extra heat, or some poor care on my part. I have another cactus in there again, and now that it is winter the heater is back on. We'll see what happens.
Mark
Mark