20 x 200gram Chlorsave tablets (4kg).  Chlorsave tablets (cyanuric acid) is a stabilizer which is added to pool water to slow the rate at which free chlorine is destroyed by sunlight. A properly stabilized pool will reduce its chlorine consumption costs by up to 50%.

Chorsave also comes in granules in 1.5kg and 3kg and in 200gram tablets in the following quantities:

5 x 200gram tablets (1kg)

10 x 200gram tablets (2kg)