I live in a 50 year old house. Original well. Recently had point of well cleaned of sludge (not replaced)because of low water pressure. We have a whole house filtration system because of bad smelling water (not bacteria-it was tested), and scum floating on top of water. Because of the spongy build up in the toilet tank(ony found in the tanks) it was diagnosed as 'bacterial rust'(even though they said there was none in the water). The filtration system worked excellently for 7-8 years, and then came the point cleaning followed by smelly 'hot' water. The water heater was 5 years old. We replaced the anode, drained the tank 3 times resulting in non oder in hot water for about 1 week only. Then it returned. We then purchased a new hot water tank (electric) and the smell went away for another week and returned.
The filtration system company checked our water again and said it was OK. What is happening to the hot water? Is it some reaction in the tank with the filtered water? Or some reaction of the anode to ?what? I'm at a loss, and can find nothing by researching the internet.

You need something more than water filtration, you need water conditioning. However, the cheap salt causes faucets and water heaters to fail very prematurely. [smilez] enjoy

It sounds like some minerals have leeched into your well and have interacted with the magnesium anode rod in your water heater creating hydrogen sulfate gas. The rod is located under the large looking nut on top of your heater. First try flushing out your heater. Attach a hose on the boiler drain located at the bottom of the heater. With the pressure left on open the hose bib and let the water run until it's clear. If the problem persists, change the anode rod to aluminum. Now check the screens on your aerators. If they are silted up clean them. Remember how you took them apart. Good luck, Tom

Good call speed ball, however, I believe I would get a test done by my local health department and not the company selling me my filters.