Precipitate in Silver Nitrate Solution

[Mark Fisher]

It seems like every time I want to do some Kallitypes, I need to filter out a dark gray precipitate (Ag, I suppose) from my 10% solution. I store it in the dark for the most part in a brown glass bottle. I figure that at some point, it will affect the quality of my prints since there is less silver in solution. I thought that the silver nitrate solution would be relaively stable in a brown bottle mostly in the dark.....guess I was wrong :confused: When do I know when it is no longer good to use?

Thanks -- Mark