Spa Marvel Water Treatment & Conditioner Application Directions Add one full bottle of Spa Marvel Water Treatment to all tubs up to 500 gallons. Even in smaller tubs, use 1 full bottle as your bather-load per volume of water is usually equal to, if not greater than the larger tubs. (In a brand new spa, add one third of a bottle, the second third in 30 days, and the last third in another 30 days.) Occasionally when the Spa Marvel is added it can be seen as white strands suspended in the water. This is normal and the Spa Marvel will go into solution once it has had a chance to circulate. Balance alkalinity (80-120) and then pH (7.2-8.2) if necessary using traditional spa-water balancing products available from your professional spa retailer. The acceptable range for pH when using Spa Marvel is much broader than when using traditional spa care products, so please take care to read your testing devices properly, keeping in mind that they are calibrated to show the "OK" range when using traditional chemicals, not Spa Marvel. Traditional spa treatment products work best at specific water-hardness levels. Spa Marvel will work at any hardness level, and given the choice Spa Marvel prefers softer water over harder water, but it is not a requirement. If your source water is so soft that it is corrosive and damages your heater and seals, then please adjust the hardness using calcium hardness increaser as per your professional spa store's guidelines. For best results we strongly recommend adding 1 tablespoon of chlorine or bromine to your spa water on start up and once a week thereafter. For example, if your tub is at a vacation home, add the chlorine weekly, again before you leave and again on your return, even if it is weeks or months before you return to use the spa. This is such a small amount of chlorine that you won't notice its presence.