Hi Red,
myredracer wrote:
It's interesting that the deposits are only on the 2nd strainer. Perhaps the screens are different metal? No odor but then it's been a few months now. I wonder if it's iron bacteria or something that feeds on iron? If it is iron bacteria, it's not a health risk at least. I wonder if it can be analyzed at a water testing lab?
Iron bacteria
I myself do not have experience on iron bacteria so don't know exactly. The screen washer you are showing looks like the standard stainless washer. While stainless can rot/corrode given the right conditions, I'm suspecting the screen itself is not rusting. It is more "something" on the screen. And yes, the right lab can test what it is.
That article on Legionnaires disease is definitely interesting and food for thought. It sounds like what you are saying is that it would be prudent for RV-ers in hotter areas of the US to regularly treat their holding tanks. When reading up on it a bit I learned that the Legionella bacteria is naturally occuring in some lakes and rivers and apparently even in potting soil. So I guess some folks *could* end up with the bacteria in their holding tanks and all you need is the right conditions for it too flourish?
Hotter climates have worse conditions then the more northern climates for elevated temperatures to grow out an infection, however climates that are damp a lot have other bad traits of mold. A good sound water program with routine system sanitize should occur regardless, however be more in-tune with the area you are camping in. Even here in the mid-west Ohio, inside the camper can hit 100F plus during a hot summer day in the sun.
The biggest thing is just realizing what can happen and what not to do. And practice good camper water management and the odds are then in your favor to not have a problem.
John