Marine aquariums differ much more sensitive to any changes in the environment. The most important parameters for saltwater aquariums are pH, salinity and temperature. Occasionally the nitrite and ammonia will cause problems. These settings do not differ from the same parameters in freshwater aquarium, but results vary greatly.
pH in a saltwater aquarium is one of the most important parameters. Marine fish and invertebrates are sensitive to changes in the level of acid-alkaline balance. Thus the fluctuation in pH by 0.2 a day is very critical. Animals prefer a pH from 8.0 to 8.4, but the level of acid-alkaline balance must not fall below 8,0
The next indicator was the level of nitrite. Fish are much more resistant to nitrates than invertebrates, but still prefer the level of nitrates below 20ppm.
Salinity, or density. In General (very General terms) is that how much salt is contained in your aquarium. Many aquarists believe that the density and salinity are the same, but if you look in detail it’s not. Density depends on temperature and salinity no. Most hydrometers are calibrated for density indications about 59F. But in any case all the animals are calmly acclimatized to the density,if it is not to be changed frequently. The density of marine aquarium should be around 1.022.
Finally, the temperature . Temperature for marine aquariums does not differ from temperature in freshwater aquariums. And should be in the limit of 24-27’C. Sudden changes in temperature cause fish stress and may promote the development of diseases, so you need a good heater.
Other indicators are to control the alkalinity and water rigidity. Special attention should be paid to control alkalinity. Without the proper alkalinity level of pH in your aquarium will greatly change that in the future could get very dangerous for its inhabitants. Indicator alkalinity should be in the region of from 2.5 to 3.5 meq/L. the Indicator of calcium is more important for the owners of reef aquariums. However, if you keep invertebrates, you must monitor the level of calcium. Without calcium and trace elements, many invertebrates will not be able to build an exoskeleton, and soon may die. Calcium levels should be 400 to 500 ppm Ca++.