Lidl is offering a Bestway Flowclear swimming pool heater on promotion. This heater connects on one side to the filtration pump and on the other to the swimming pool.
It can heat the water from 0.5 to 1.5°C per hour, depending on the volume pool and weather conditions. Note that this heater is designed for swimming pools with a volume of 1520 to 17,035 liters. It costs 119 euros instead of 139 euros on the Lidl website.