I don't think overwatering is a problem with these guys. We grow ours in New Zealand moss and a saucer, that holds water all the time. The moss is soppy wet all the time. Has grown a new leaf this year and are hopeing for a flower spike. Have had very little tip burn on any leaves and the pseudobulbs stay plump. I don't know if you can overwater them. Just make sure you provide them with good air movement.