zinc or copper to prevent roof algae
 

what is better zinc or copper to kill algae on a roof

what is better for killing algae on a roof, zinc or copper?

Both will work, zinc strips by far are less expencive.
Installing a darker shingle, making sure there's no over hanging trees, making sure the shingles contain an algicide will also help.

zinc or copper to prevent roof algae
 

I concur. Zinc is far less expensive. As long as you clean all the moss, mold, mildew, etc... off prior to installation the zinc will take over from there keeping the roof clean.

I get my zinc from a company is CA called Rotometals. They seem to be cheaper than other companies. If I buy more than $99.00 worth they ship it for free.