The rear wall is of AquaDecor
The stones I get carved from large up to 500 kilo chunk with a jackhammer into manageable pieces. Then, at the most beautiful specimens of the sharp edges have been trimmed and rounded, so the risk of injury to the fish disappears. The stone is broken Warsteiner commonly also called alpine limestone. Learned from a stonemason that it is the same rock layer. The name is solely based on the mining area.