I repotted my ficus benjamina bonsai in a 5 gallon bucket hydroponic's system. The goal is to increase: fine white root production, top growth, shaping, ease of watering and feeding.
Bonsai is basically a tree that is shaped to look mature, while being planted in a pot or tray. Hydroponics is a growing system used to feed and water a plant efficiently without the use of soil. There are many different types of hydroponic's growing methods. This one uses a DWC (deep water culture) hydroponic system.
The roots are contained in the net cup of the lid. Clay rock was used to fill and support the bonsai. PH balanced water and nutrients were added to the bucket, just enough for new roots to reach for the feeding source. The water and food will be changed every two weeks.
It's important to oxygen the water. This will allow the roots to breath under water and produce new growth; also preventing root rot. I am using an air pump, just like one for a fish tank. It simply pumps air through tubing, out and air filter and directly into the nutrient rich water.