Tired of cleaning the trough every other day? The Water Wych has been proven since 1993 to purify water and absorb the nutrients that make algae grow. The unit it made from Volcanc Rocks, Carbons and Silicates and is perfectly safe for all animals and aquatic inhabitants. Simply place the Water Wych in your trough or automatic waterer's float chamber and over the next 2-4 weeks your water will be clear, starving out your existing algae and stopping any regrowth for the life of the unit. 1 unit can last from 1 - 4 years depending on water consumption. Just remove any food or hay left floating in the water. The Water Wych is safe to leave in through the harshest of winter months and can be used with trough heaters.