Dark particles from hot water heater

Cant say for sure if this is it but at my work we have had a problem with a black gunk on the hot side. I called the water company they came out and tested to make sure but they said "yeah it is normal and well within the water specs" Turns out it is some sort of a benign bacteria that is in the water, and that it proliferates in warm/hot water. The black stuff is actually dead bacteria. It is only seen or noticed in low flow/use applications. Where it has a chance to build up. Well regardless of what the water company tells you nobody wants to see black particles, chunks or grey water coming out of the hot side of the faucet. So I called a water place like culligan. They came out and shocked the entire system with bleach. Flushed it did that a couple times to kill whatever was in the lines and water heaters. Then they put in a tank that we put x amount of bleach in and then fill it with water and it injects it into the water line via a flow meter. The tank is probably 75 gallons or so and we add one gallon of bleach to it when low refill with water. Have not had a problem with it since. Obviously you are not going to put a large tank like that in your rv. However there may be some other way to chlorinate the incoming water or at least to chlorinate the heck out of the system and flush a couple times to kill what is already in there.
Again may not be your issue but might be worth a call to your local culligan or other water treatment companies in your area.