From the makers of the popular Dog Rocks line of products, Trough Rocks are an all natural rock sourced right from the ground. When submerged in your water for horse or livestock, these paramagnetic rocks inhibit the growth of algae and bacteria giving your animals cleaner and healthier drinking water for longer. The paramagnetism of the rocks causes a simple ion exchange to occur where the bad free molecules that cause algae and bacteria to grow are bonded to the rocks and removed from the water source. Trough Rocks won’t clean your trough so before you use them, your trough should be emptied and cleaned. Then simply refill your trough, remove the tag and submerge the Trough Rocks bag. The paramagnetic rocks lose their charge in water over time so set a reminder for yourself for 4 months to replace them. Your horses and livestock will thank you!