If you aren't buying almost 100% pure silver nitrate i can cause lot's of fogging problems.
This week i received a batch which made me doubt about the quality.
The crystals were much bigger as normal and the colour was off-white.
The good grade (at the right) is like very fine sugar and extremely white.
So i decided to do a test. I made a new silver bath and made some comparisons with my old silver bath.
As you can see on the first plate there is some fogging (after developing and fixing).
So fogging problems are not always caused by ether, alcohol or other ingedrients.
So don't try to save a little money on your ingedrients.