Interesting idea. I've never thought about that but it does intrigue me because we have really hard water here - it'd be nice to know if it was causing (I'm thinking not likely) or compounding existing joint issues (this seems possible). The barn where we start and halter break all of our calves has much softer water, and we see problems there too, so I don't really know if it has any effect or not. I'd be interested to hear if anyone else has thoughts on this...