green water

[triple d]

I am switching from Bacuacil to chlrone. I have changed the sand in my filter and water test have shown NO Baquacil, when I put shock in my pool it turns green. After about 24 hours it will start looking like it may clear. The teast strips show that I need to add more chlorine, when I do, it turns greener. What is up with that?

[Backglass]

Could be copper. Copper will turn your water green when shocking. Take a sample down to the pool store and have them test it.