I'm sorry; we usually tell people to get a kit, but in this case we missed it.

+ Here are links to the kits we recommend:
HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon
You need to find out your CYA levels, to help us answer your question. But, in general, you still need to chlorinate if you can't hold chlorine overnight. Rapid chlorine loss during the DAY usually means low / no stabilizer.

HOWEVER, you do NOT want to "shock" the pool, or add a lot of chlorine all at once, till you are fairly sure little or no copper is left. A large dose of chlorine will tend to cause the copper to stain!