its the cleaning
Shock it with chlorine shock at the rate of 1lb per 10kgal.
The chlorine is reacting to minerals in the water.
The only reason the pool would turn green would be if the Baquacil is not entirely out of the pool and it reacts with the Chlorine.
You can add liquid chlorine by walking it around the outside edges of the pool or adding 3 inch tablets through a chlorine floater.
Stop adding salt to the pool and use tablets and shock when needed.
Pretty much --Yes.
The chlorine
not necessarily, it depends how much chlorine you have in your pool. the more chlorine the better you have a chance of turning it green.
the chlorine make blond hair turn green. if you use chlorine shampoo it should get it out.
you should have your pool tested just to be on the safe side.
Your pool water may have turned green even after adding Fresh and Clear because of metals in your water. It is likely copper that is causing the water green. Your pool store will have products available to remove the metals and clear your water up. You might also have algae if you are not putting enough chlorine in the pool.
Possibly you need cyanuric acid to stabilize the pool. Available at the pool shop. Try adding some 12.5% liq. chlor plus the above product.