The tubs you see in the picture is the bees’ water supply.
Bees need water to cool the hive (by evaporation), to feed brood (brood food is 70% water), and to dilute their own food (honey, sugar syrup or nectar). It is the main task of some bees to find and bring in water (they make about 50 trips a day for 0.000881 oz of water per trip). If the hive is short on water, other foragers will stop collecting nectar and pollen to help with the hydration effort. When it’s very hot, a colony needs about half a gallon of water a day.
The conscientious beekeeper had better supply some water, the closer to the hive the better, not just for the bees’ health and the honey production, but also for keeping the peace in the neighborhood. If bees bother the neighbors, it’s probably because they’re looking for water, on laundry on the line, in swimming pools, in the trays of potted plants or gutters.
Hence, the tubs. The first experiment was the galvanized tub on the right. It is filled about 1/4 with stones, arranged in a slope so bees can gradually approach the water without drowning, even as the water level goes up and down with rain and drought. Within days of installing it, it got grubby with leaves and insects. I am dumping it out at my next hive inspection.
So I added another tub (on the left). Its “beach” is simply a small plank held down by a stone. It holds two oxygenators: a floating water hyacinth that will also provide a landing platform, and a submerged Hornwort. I also added some capfuls of natural enzymes that are meant to keep bird baths clean. The product is called Birdbath Protector, by Carefree Enzymes and it’s safe for all wildlife. Let’s see how this one does.
Running electricity to the tub for a pump would be problematic, but at some point we might want to run a line into the veg garden anyway – for ventilating the hoop house with fans, for instance.