Lead and Manganese Stains on vinyl siding

[GumDestroyer]

I washed a white vinyl sided home today that just looked like it had baked on dirt but later discovered it's a hard yellowish brown iron stains due to very hard water from sprinklers. I applied SH12% along with simple cherry, joy soap and 200 deg water...no change. I used my soap tip the whole time to be fragile but nothing broke up the stains...
Tried some BT200 and it didn't break it down. scratch test didn't work. Back to the Iron Stains drawing board. I don't want to discolor the siding or brush it. I would think theres a product for hard water that will break it up and wash it away? Frustrated. :smad:

 

[GumDestroyer]

Phosphoric Acid seems to be most effective but I do not want to alter the ph in the soil. I will saturate the soil first and use a pump sprayer with adjustable nozzle. The Phosphoric worked well in the past and is the main ingredient in "The Works"- "Rust Magic" and Boeshield Products.
I will stick to flat surface cleanings. lol

 

[GumDestroyer]

Crazy me. I meant Iron and Manganese...lol