The weekly test of the sprinkler system had literally left its mark on our spheres. Over three years it had discoloured them, but this was just cosmetic. However, the authorities were concerned this might be a rusting problem.
We therefore put things beyond doubt with a complete clean up and re-paint which ran from August to October. But this caused another issue. The Town Planning team, visiting on another matter, was convinced the sparkling tanks were new. We had to show them approved drawings to prove they were in fact three years old. Now – we think – everyone is happy.