Croffle

A blanket of croffles (hollow polythene or polypropylene balls) is an effective way of covering the surface of liquid in the tank. The croffles have a raised seam so that they interlock and do not rotate which would otherwise expose a wetted surface to the tank roof space.

Whether you're in the market for a gourmet full English, vegetarian alternative, or a sweet croffle (croissant-waffle hybrid) with a coffee, this is the place to go.