I'm sure this was in the old forum but should probably be asked again...

Anyway, has anyone used those cheap "Solar Fish" instead of a bubble cover?

The theory is it places a thin layer of something (oil?) to reduce evaporation.

It supposidly works better if you don't run the pump (or maybe redirect the returns from the surface)

Does it work? I don't want to mess with a bubble cover, but could use some cheap heat gain.

Robert