Not so much a water issue, but application. 550 GPM iron removal, high SDI, no chemical injection allowed. Our pilot testing showed Pyrolox was the right choice with Turbidex pre-filter. Ended up using the aquamatic quad backwashing filter design.
Worst water, hand dug well, 30 feet deep, in a low lying area where runoff constantly gets into it from cow pastures... I refused to guarantee any equipment or perfomance...
Ended up with Chlorine injection, contact tank, GAC, nitrate and softener systems, Ozone in storage tank, UV after tank, ro for drinking water with post UV. And a disclaimer that I want nothing to do with the performance and that they should not drink or allow skin contact with the water.