Solution increasing calcium level of water. Application: 10ml of the solution increases Ca level of 10mg/l in 100l of water. Maximum daily dosage is 20ml in 100l (27 US gal.) of water. Calcium level in reef aquarium should be kept at around 430mg/l. US: 2 tsp of the solution increases Ca level of 10ppm in 27 US gal. of water. Maximum daily dosage is 4 tsp in 27 US gal. of water.