These are the little stories that happen next to a biological pool and that make this equipment so unique.
Know what a strider is? Yes, you know, or you do not know looking to this picture?
It’s a small insect, which lives on the water surface of ponds, streams and biological pools. They are small bugs, many not bigger than the tip of a finger, but they can skate above the surface of water without getting wet! They take advantage of the so-called capillarity of water, that is, of the physical forces between the water molecules that allow the water to fill the glass a little higher than the glass itself. The same physical effect also exists on the surface of the biological pool and so the animal can walk on water without sinking. But it also helps an anatomical specialty in the front paws: tiny hairs form a kind of bag to hold an air bubble. In this way the animal is rowing above the water surface with the behind paws movements. The air cushion beneath the front legs makes no resistance at all and so the striders can skate with great speed above the surface. And what do they do there? Mostly they are looking for prey, other insects fallen in the water for example. Because striders belong to the large group of bugs and are insectivores.
For people they are totally harmless and always good companions to watch was happens on the surface of a biological pool.