Check the listing for details. HY Hydros Dosing Pump. Condition: New. Listed at 72.75 USD. The Hydros Dosing Pump is a high-quality and reliable pump designed specifically for dosing tasks in fish tanks or aquariums. With the Hydros brand known for its dependable products, this dosing pump ensures accurate and precise dosing of water additives such as beneficial bacteria, nutrients, and supplements. Perfect for maintaining optimal water conditions in aquatic environments, this pump is a must-have for aquarium enthusiasts looking to keep their fish healthy and thriving.