bunny ear cactus turning white

[Planturion]

My cactus is turning white or gray from the bottom up. I barely water it and it's not soggy. The dirt isn't even wet. Is this a light issue? It's under grow lights so I'm wondering if they're too close.

 

[cpp gardener]

Unless the stems are mushy there’s not a problem. Since your cactus will grow in full sun, you really can’t put it too close to the lights.