I was thinking about geting. Only a Koi pond with rocks only the top foot of the.pond and rest the liner. But I was wondering how the the liner will look after.a.while? Does it turn green? I like how the rocks.look even with a little algae but I don't want it to be bad for the.Koi, and I've seen some liners and they seem to turn green after a while and I don't like the.folds you see in there? What would you recoment and any pictures.would be.helpfully. 