I do, and here's how I do it. I take the old potting soil, put it in a 3 gallon pot, and pour a kettle of boiling water through to kill it, then I mix it half and half with new potting soil. Things grow very well in this, and I've never had any root rot problems from the old soil.
Didymo (Didymosphenia geminata), also known as rock snot, is a non-native invasive microscopic algae (diatom) that can produce large amounts of stalk material to form thick brown mats on stream bottoms.
The physics of the didgeridoo (didjeridu/ yidaki/ yiraki), presented for non-specialist readers. The didgeridoo or didjeridu is the yidaki or yiraki in the language of the Yolngu, one of the peoples of Northern Australia, where the instrument originated.