StabHi pH Pebbles for controlling acid creep in your pond. Handy 4x 4kg (3.6 liter) net bagn for easy handling in a box. Use StabHi to both act as an substrate for biological filtration and a source of carbonate to counter "acid creep" (the process of acidification due to nitrification) automatically while adding calcium. Every pond should have a bag or two to help stabilize the pH and supplying essential minerals. StabHi will slowly dissolve as it does its job at increasing the alkalinity. The rate it dissolves is dependent on things like the fish load, feeding rate, water and if other sources are present. Will not leave an organic residue like oyster and abalone shells. Versatile. Hang, spread or apply in the flow of the water. As is in the bag or out of the bag. On top of your sand filter, in a stage of the bakkie-filter, between the brushes of your vortex drum. Total Weight: 16kg 4 x 4kg bags in a box (Keyword: pH control, acid creep, acidification, acid prevention)