Quote Originally Posted by lonbeme View Post
Will it work, or is the light/algae being able to get through a problem?
Will it work, for what?
=> will a mesh cover keep out light? No.
=> will a mesh cover keep out algae? No.
=> will a mesh cover look better than a plastic cover? Yes.
=> will a mesh cover keep pets and people from falling in and drowning? Unless they work at it, yes.

There is such a thing as a waterproof and light proof mesh cover, but it's a sort of "worst of both worlds" beast.