Marine Buffer will safely raise marine pH to 8.3. It will not raise pH above 8.3 even if inadvertently overdosed. Marine Buffer is a blended product and is not just sodium bicarbonate or sodium carbonate, commonly sold as a substitute. Such products can raise pH to dangerous levels if not used properly. Marine Buffer contains sodium, magnesium, calcium, strontium, and potassium salts of carbonate, bicarbonate, chloride, sulfate, and borate. Use Seachem's MultiTest: Marine pH & Alkalinity to check pH and total alkalinity.