HELP Nerite trouble!!
 

I have 4 nerites in a 10 gallon and got them before I learned that my water was soft because I was having alge problems and now my nerites shells are turning whit and getting hols in them.So i talked to some snail people that told me to get a coudlbone and put it in but,how much do I put in,will it make my water cloudy or poison my fish,and how long do I leave it in there?:-(:cry::-?

You could, but there are many tablet products that are much safer to use

Or there may be liquid solutions