Curious title perhaps but the photos below are of the inside of one of our water tanks at our Schoonspruit/Skoonspruit camp! Perhaps it explains why we used to drink so much beer in the evening!
The problem with the water tanks we had in RSA were that they were translucent plastic. In Libya our tanks were stainless steel or rubber bags. No light got into those so algae growth was negligible. But in RSA, the light would easily penetrate our yellow and blue plastic water tanks and algae growth was always a problem. Usually all it took was a pressure washing of the inside to flush out the gunk, but still!
I think it makes a nice abstract B&W textural image while the original black and yellow version also holds its own.