1 LITER Brightwell Aquatics Alkalin8.3 33.8oz Marine Reef Concentrated KH Buffer

Basic: Shake product well before using. Add product at the maximum rate of 5 ml (1 capful) per 30 US-gallons daily until the desired alkalinity is attained, then dose daily or weekly as needed (see below) to maintain alkalinity between 7 - 12 dKH.

eBay