HT Chemicals are made in the USA and are the proud sponsor for HotTubChemicals.com. They along with other US manufactured chemical brands specifically formulate their products for hot tubs, not swimming pools, and are sold exclusively through local hot tub retailers. They include the highest concentrations of active ingredients available and are produced within highly monitored quality control standards. This means that you will use the least amount of product to maintain clear healthy water versus some suppliers that save money by watering down their liquids and adding fillers to their powdered products. We strongly recommend buying hot tub chemicals from local hot tub retailers.