Flush the gunk! How to thoroughly flush a water heater to save $$$ 

A recent post from a professional plumber shared this with me: Aluminum hydroxide looks like "jelly beads" or a green, blue or gray gel-like substance in the heater drain or at faucet aerators. The substance you are showing is a result of minerals reacting to the anod rod inside the heater. It is not a bacteria. Legionella is an aquatic bacteria that thrives in warm water environments and is the cause of Legionnaires Disease.... It also is accompanied by a foul sulphur smell. And has no visual indicators.