CuSO4.5H20 Pack contains, 2gm of this fining agent. It removes the H2S, the rotten egg like smell that comes from stressed yeast (which is usually caused from a combination of lack of yeast nutrients, high temperature and too much sugar levels in the primary)

Use sparingly (copper toxicity) and follow the expert fining agent guide for the exact quantity and usage instructions.

Copper Sulfate fining