Description Welson 511 is a powder product used in swimming pool to control algae, fungi and bacteria. It is easy to use, safe and harmless, and has a good degerming function with a low dose. Dosage Adding 2-2.5 kg per thousand cubic meters of water will maintain 0.3-0.5 mg/L of free chlorine. Safety This product is an oxidizing agent. Avoid contact with skin, eyes or mucous membranes. Don’t mix with acid products while in use or neutralize agent in case of producing harmful gas. If swallowed, do not induce vomiting. Drink milk or water and seek medical attention immediately.