Formula of chemical composition of components 1+, 2+, 3+ is based on method developed by H. Balling, however, it has been modified and enriched with microelements necessary for normal function of a marine aquarium. This way, we have obtained 3 fluids intended for dosing in equal amounts on regular basis in order to fulfill coral demand not only in terms of magnesium and calcium, but also in terms of all other elements, which doses may be difficult for establishing under home conditions, and which require careful and systematic dosing. Maintaining adequate level of magnesium and calcium allows preserving suitable amounts of microelements in a reef aquarium (Ca 400-440 mg/L, Mg 1280-1350 mg/L). In case of a reservoir containing average number of hard corals, the dose is approximately 50 ml daily per 100 liters of water. Component 1+ contains: Ca, Mg, Sr, Ba, Co, Mn, Cu, Fe, Zn, Ni, Cr ( 50ml raises of 9 mg Ca/100 l and 0,6 mg Mg/100l ). US: 1.70 fl oz. daily per 27 US gal. of water. 1.70 fl oz. raises of 9 mg Ca/27 US gal. and 0.6 mg Mg/27 US gal. ). Component 2+ contains: NaHCO3, F, I ( 50ml raises the KH of 1,3 dkh-Alk 0,46 meg/l in 100l ). US: ( 1.70 fl oz. raises the KH of 1.3 dkh(Alk 0.46 meg/l in 27US gal.). Component 3+ contains: mineral salts and K, Bo.