Possibly; difficult to say for sure. Looks like possibly a pH issue also. The other possibility is a high ppm issue; drainage issues; ect...
Should know about the water there; your the one doing it. Have the pots been allowed to dry out in-between watering.... I always check the heft of the pots; also feel into the top level about an inch down... before adding water again.
Needs to be at minimum; about half the full weight. Lighter the better; up to a point.