Discus Buffer™ adjusts water to any acid pH in the range of 5.8–6.8. It is completely compatible with Neutral Regulator™ and may be combined with it in fixed ratios to yield a preset pH. It is totally phosphate based and is free of carbonates. It will also soften the water by removing calcium, magnesium, and other divalent cations as precipitates. A 250 g bottle treats over 800 gallons. Freshwater use only.