Using a calcium reactor can dissolve big amounts of Calcium and trace elements like Strontium and Magnesium into your aquarium, that can be taken up by the animals.

Calcium reactor

See details AQUA-EXCEL C1 Model: C1 Spec: 26cm*16.5cm*46cm(L*W*H), Reaction pipe diameter:120mm Match 1 litres import high grade calcium sand Power supply:220V/50Hz 10w See details AQUA-EXCEL C2 Model: C2 Spec: 26.5cm*17.5cm*56cm(L*W*H), Reaction pipe diameter:150mm Match 2 litres import high grade calcium sand Power supply:220V/50Hz 35w See details AQUA-EXCEL C3 Model: C3 Spec: 32cm*21.5cm*69cm(L*W*H), Reaction pipe diameter:200mm Match 3 litres import high grade calcium sand Power supply:220V/50Hz 35w