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.
Didyma in Turkey contains the ruins of the temple of Apollo, which was one of the most important oracles of the Hellenic world. Dion. Dion is an ancient city in Greece which became the religious centre of the Macedonian kingdom and now contains a number of Greek and Roman-era ruins.