rockm

The solution to root rot is not to let the soil become soggy over a long period of time. That means you will have to learn when your tree needs water and then water it.

I learned to water bonsai by using the weight of the pot and the color of the soil--which is the most reliable way to gauge when a tree needs water. First, water the tree THOROUGHLY and completely. This means, water it for a few minutes, wait a few minutes until the water runs out of the drain holes, then water thoroughly again. You can repeat this several times, the aim is to completely saturate the soil. After you're confident the soil is moist throughout, pick the pot up. Gauge the weight in your hands. It should be pretty heavy, as the soil should be holding a considerable amount of moisture. Additionally, note the color of the soil's surface. It should be darker in color.

Put the plant in its place. Wait a couple of days. Pick the plant up again, note the weight. Should be a little lighter, soil surface should be paler. Dig down an inch into the soil. Should still be moisture then. Most likely, NOT time to water.

Wait two more days. Repeat the above procedure. When it's time to water, the pot should be at least half the weight it was when it was thoroughly wet--ficus can be kept on the drier side, so less than half is probably preferable.

Do this repeatedly and you will find yourself being able to tell soley from the soil's color when it's time to water.