Hi triple M! Welcome to TFP,
I moved your post to a new thread here on its own. You can switch easy. 0.3 is enough to cause staining on plaster, but I don't know what the threshold is for hair staining. Whatever you have, it sounds like enough, and I suggest a drain/refill. Best to leave a foot minimum of water in a liner pool so I wouldn't take it further than that. Drain half and replace then do it again. Or, do it in thirds if you want to be really safe. We shy from anything with Copper because of staining. We are big on testing our own water and maintaining critical parameters with common products like Bleach, but our cornerstone is understanding more than anything else. Take a look at Pool School, and start with the ABCs. You'll need a good test kit, but the know how is all here, and plenty of people will help you along the way.