Femanga shrimps Active important minerals for shrimps. Mainly used are calcium and limescale absorbed through the lining, so help with the housing. With Femanga shrimps Active can now make the important minerals and with the water. Femanga shrimps Active is a purely natural mineral solution that is free from animal proteins and not affected by growth. The minerals will be covered by the shrimps as padding, so as to support the structure and provide an ultra strong shell. Container Volume 250 ml – enough for 2,500 litres.