Ok, i've got a problem with a few of my anubias. I got them about a week ago and planted them in gravel/eco-complete mix. The roots and rhizome are underneath the water, and the rest of the plant is in the air. Several leaves from 3 of the plants have fallen limp to the ground and when pulled on them slightly, they came right off. The stems of hte leaves all the way down to the rhizome seem very mushy and flacid, sorta look like avacado. What is going on?