Specific gravity is the measure of relative salinity or the amount of dissolved salts in your aquarium water in comparison to pure water. Being reef aquarists you all be aware of the importance of maintain a constant specific gravity in order not to stress the inhabitants of your aquarium. Measuring specific gravity on a regular basis is essential to keep up the idyllic environment for your aquatic inhabitants. It is important that you never ignore this fact even if sometimes you might think it is not as important compared to the other factors that need to be taken care of in a reef tank.
Any ignorance in maintaining specific gravity in a tank can result in stressing or imperfect nurturing of your corals and other aquatic pets. The best way of keeping it perfect and constant is by keep a regular check on them. Most aquarists use either a simple hydrometer or a refractometer to measure salinity. For proficient results consider a portable refractometer or a high tech electronic salinity monitor.