The Source for a Chlorine Free Lifestyle SIGMA offers a full line of water conditioning products for your home and pool. From our Chlorine Free Pool System to our state-of-the-art Whole Home Water Conditioner, SIGMA manufactures the most advanced water treatment systems available. Sigma Systems are user friendly and environmentally safe. We hope you enjoy visiting our website and find it informative. Please contact us with any questions or comments you may have. Have a great day and make today a healthy one.