I've had a pot of three different succulents since the summer and all was going well. On the advice of the shop where we bought them, I've been giving the pot a good soaking once a month but making sure the water has drained all the way through before returning the pot to its spot in a south facing window that gets direct and indirect light. From last month's watering to this month's, the leaves on the haworthia have started to turn brown and crispy. The rest of the leaf feels normal, with a good amount of "give" as with an aloe leaf. Is the cause underwatering? Should I trim the dead material off the plant? Thank you!