Find out all about it here. Keeping this in consideration, how often do you water a Easter cactus?
Water them anywhere from every 3-6 weeks depending on the temps, the mix it's in & the size & type of pot it's planted in. You want to keep the temps between 50 & 65 degrees F. 50-55 degrees is best at night. If your temps are warmer, they'll require a longer period of darkness.
Secondly, what's wrong with my Easter cactus? Like all succulents, Easter cacti do not need a lot of water. In fact, overwatering is another problem that can lead to root rot and other fungal diseases. During the growing season, water when the medium feels barely moist to the touch, but let it dry out a bit between each irrigation after the flowers have faded.
Then, why are my cactus leaves falling off?
Giving succulents too much water too often will swell their leaves and, if they do not get a chance to dry out, cause them to drop off the plant. Wait until soil is almost completely dry and the leaves look a little limp before watering, then water thoroughly, until you see trickles coming out of the bottom of the pot.
How do you revive a dying cactus?
Save A Dying Cactus: How To Revive Your Plant