Iron Bacteria

Hey guys,

Just bought a new house, built in 2005. I did a pre-purchase water analysis which discovered:
- arsenic (0.013 mg/l)
- baryum (1.44 mg/l)
- lots of total dissolved solid (872 mg/l)
- lots of iron (0.486 mg/l)

Other than that, just for your info:
- pH of 7.93
- conductivity of 1230

The old setup in place was a greensand filter regenerated during backwash with potassium permanganate; nothing else. There was nothing really wrong with it, with no sign of iron bacteria, but it was 12 years old and had never been maintained so I decided to install a totally new setup that would address everything include the arsenic.

I went with the local professional that had the best reputation in the area. They came up with this solution:
- air injection iron filter to address the iron issues
- metsorb to address the arsenic
- classical salt filter

All went fine for the first 2 weeks or so, except some issues with the air injection itself. The air bubbles in the water intermittently clogged my Brita filter and my Nespresso machine.

After 2 weeks, we started noticing smell of rot or decay with the cold water line. I contacted the installer, which generated some back and forth for another 2 weeks, and the smell got worse. What I don't understand is the fluctuations. Sometimes it barely smells, sometimes we can't stand it.

They came over and confirmed the presence of iron bacteria.

They are coming over next Thursday to convert the air injection filter into a greensand filter. According to them, since iron bacteria was not an issue before installing the air injection, concentration is low enough to not require a chloration/filtration system.

What do you think?

My concerns:
- will the greensand really take care of these low concentrations
- since we've been using the current setup for 1 month, did the iron bacteria screw up the metsorb and salt filters. If so, do we have to replace the media or if backwashes will bring them back to life?
- the water lines are made of Pex. Since iron bacteria is now present in the entire house (cold water line, toilet, etc), should I threat the system or if the bacteria will go away once we resolve it at the source?

And finally, is the installer responsible for this mess? Given that the neighborhood is known for iron bacteria, should they double check before installing air injection? Or if I have to pay to get everything fixed up?

Thanks for your help!