Check the listing for details. Seachem Marine Buffer 250 gram Saltwater Aquarium pH Alkalinity Stability Powder. Condition: New. Listed at 14.99 USD. Seachem Marine Buffer 250 gram Seachem Marine Buffer is the original and still unique buffer with a pH of 8.3, designed to adjust pH to 8.3 and maintain both pH and alkalinity(KH). It is formulated not to disrupt the natural ionic balance of marine water with prolonged use. Marine Buffer contains a natural balance of sodium, magnesium, calcium, and potassium salts of carbonate, bicarbonate, and borate, formulated for enhanced and lasting buffer capacity at pH 8.3 without sacrificing calcium. It dissolves readily and does not obscure water clarity. The original Marine Buffer remains clearly superior in both composition and performance and is the choice of discriminating aquarists. A 250 g bottle treats 800–1600 gallons. Marine use only. Size: 250 grams