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.
Remember when you are changing water, you must check the salinity of water in which the livestock was kept in. After the change of water make sure that the new added water’s salinity also measures the same as that of the previous water. Greater deviation in specific gravity can shock the aquatic inhabitants or sometimes even kill the highly sensitive ones.
Reload evaporated water with clean freshwater and not prepared salt water. Remember, salts remain behind in the tank after water evaporates. If you fill up your aquarium with salt water, you are compounding salt levels in your aquarium which will lead to large deviation in specific gravity.
Whenever you buy a new aquatic inhabitant (whether fish or coral), always research their ideal specific gravity. Try maintaining similar salinity in your quarantine first and then the main tank. This will lessen the stress that newly added aquatic pets face in a new environment.
Hydrometers can be really helpful in measuring the specific gravity in aquarium. But be very careful while choosing your reef tank hydrometer as some fake ones can provide inaccurate measures or sometimes even fail to work. Instant Ocean Aquarium Hydrometer is a quick, easy and accurate calculator of aquarium’s salt level and specific gravity. Its full range scale features easy to read markings with safe zone clearly indicated. No-wet-hands-design! Accurate to +/- 0.001 reading are achieved with this hydrometer. It is ideal for use in water temperatures from 68 to 85F.
It is a must have tool for reef aquarists and you don’t have to pay much for it. At amazon.com you can get Instant Ocean Aquarium Hydrometer for just $10.29. It is easy and convenient to use. All you have to do is drop it inside and let it fill up and you’ll get a reading in about 15 seconds just make sure to give it a good flick with your finger to knock off any microbubbles that could throw off your reading and you should be good to go.
Though hydrometers are convenient to use while mixing salt for a saltwater tank, yet its accuracy is doubtful in the long run. For best accuracy on a refractometer can be relied upon. These accuracy optical instruments are extremely precise even at very low salt levels, and are equally effortless to use. Lately, these devices have become more inexpensive, so now every aquarium owner can have one to help supervise water conditions.
We recommend Vertex Salinity Refractometer with Auto Temp. Calibration for accurate measurement of salinity in reef tanks! It is easy to read and quite reasonably priced. It features a Clear View oversized display to guarantee the easiest, most accurate readings possible in two scales (±1.0% salinity and ±0.001 specific gravity).
VertexTM Refractometers also feature Automatic Temperature Calibration (ATC). Simply put, the unit will self-adjust all samples to the proper reading temperature, increasing the ease of use. Additionally, the insulated, non-slip rubber grip will keep external sources of heat, such as hand warmth, from interfering with an accurate sample reading.
Robust Construction VertexTM Refractometers have all-metal body housing for added strength. A large rubber hood both provides extra security to the eyepiece and checks foreign light from entering the unit body. It takes less than a minute to read its measurement. Simply place a few drops of water on the refracting lens and look through the eyepiece and take note of the boundary between blue and white. That’s it! You now have an accurate measurement of your tank’s salinity. Value Protect your investment. You can get VertexTM Refractometers from amazon for $40.