ALTERNATIVE ENERGY FORUM - etc.

I got a surprize this morning. Yesterday I mixed some copper sulphate crystals in water and sprayed it onto my pond for algea control. The bucket had about 1/4"  of the mix left over night.
I absent mindedly threw a steel grid in the bucket and it sat over night.
Today I decided to mix another batch and re treat the pond.
I pulled out the steel grid and found a thick layer of cppper deposited on it. I could actually peel it off. I measured the thickness and it was .014" thick. 
No anode, no cathode, no electric current.
Too bad we can't just draw this on a bare fiberglass board to make a circuit.





https://www.dropbox.com/s/fhabbukvatccff9/IMG_20210325_130006438_HDR.jpg?dl=0

https://www.dropbox.com/s/2ghxq26xn5oetqt/IMG_20210325_125952799_HDR.jpg?dl=0


https://www.dropbox.com/s/vcpi8nbod95wz8y/IMG_20210325_130017783_HDR.jpg?dl=0


https://www.dropbox.com/s/2zmjjuz6ijrfumb/IMG_20210325_130603328_HDR.jpg?dl=0

https://www.dropbox.com/s/xcyallxzpclowdn/IMG_20210325_132427951_HDR.jpg?dl=0

I always thought you needed to supply an electric current (substantial) with two electrodes.
But I just found this> https://www.instructables.com/Copper-Plating-a-Quarter-Without-Electricity/