Re: does cupric sulfate keep swimming pool water looking cleaner and is it safe

Swimming pool water looks clean and clear when there are few organisms 
capable of growing in the water.  This is generally done in two ways:  
(1) controlling the pH with the right combination of acid and base and (2)
using a disinfectant that will control bacteria and other organisms.  
Generally, chlorine is used in swimming pools.  Sometimes bromine, another 
noble gas, is used in hot tubs and smaller pools of water.

Copper sulfate (aka cupric sulfate) has many uses, but it is primarily 
used as an antifungal agent.  In other words it inhibits the growth of 
fungi.  Here in the Pacific Northwest, where I live, strips of copper 
sulfate are put on roofs to inhibit the growth of moss.  As it rains, 
copper is leached from the strip and prevents moss from growing. 

Copper sulfate is very toxic.  It is a very strong irritant to skin and 
mucous membranes.  If ingested it can affect blood cells, liver and other 
internal organs.  

Copper sulfate is most often used in agricultural products.  Small amounts 
can be found in children's chemistry sets.

As far as your pool goes, not at all recommended.  For a clean, clear 
pool, there are many products specifically designed to be used safely to 
accomplish that goal.