There are chemicals to balance the water and neutralize the metals. I'd recommend taking in a pool water sample to a local dealer and seeing what it would take to get the water into balance. I know BioGuard dealers have water testing labs, you just need to bring in a quart of water in a clean ziplock baggie (they also recommend to not let it set in the car all day, as it can change the readings - under an hour is ideal). I did a search on the BioGuard website and found this dealer near you:
Lifestyles Hotsprings & Spas
14465 N Us 27
De Witt, MI 48820
www.hotorcold.com
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I worked at a swimming pool store for a few years when I was in school and we were also on a well, so I know it takes a little extra work in getting it balanced initially. However, once you get it situated, it's easier to maintain for the duration of the summer.
There may be other local dealers that carry other lines and offer water testing, which may be closer - I just figured that this would be a good place to start.
If this is a kiddie play pool, you might just ask them to test for metals and go with the spa line of chemicals (smaller qty) and try a little of the chemical recommended to neutralize that - see how it goes?
Best wishes!