If you’re new to the hobby of fishkeeping then you may have heard the term “specific gravity” bandied about and wondered what it’s all about. In simple terms, specific gravity measures the salinity of the water in your tank; “salinity” refers to the amount of dissolved salts which are present in the water. The balance of salinity is vital to the health of your aquarium’s inhabitants and most hobbyists use a hydrometer for the purpose of measuring the salinity of their aquarium. Some fish keepers like to use a refractometer which will offer especially accurate results though deciding which you prefer will be a matter of personal preference and as with all equipment for fish keeping, it’s often best to discuss with other hobbyists before you try something new out.

The refractometer is an amazingly precise instrument which will give very accurate readings of the salt levels in your aquarium, noting even the most miniscule of changes which might occur on a day to day basis and although they were once quite expensive to purchase, the have recently dropped significantly in price which means that more hobbyists can take advantage of the considerable benefits which they offer…it doesn’t matter how large or small your tank, a refractometer will help you to manage the water quality in a very reliable fashion.
The refractometer is basically an ingenious optical tool which allows the user to add a little water to a prism glass and then read the results which are provided on a small scale. The scale is actually inside the instrument but a magnification of it is provided so that users can easily read the results. By dint of keeping such a close eye on the quality of the water in an aquarium, hobbyists are in a great position to maintain the best possible water quality for their fish, plants and corals.
Before you perform a water change in your tank, you should measure the specific gravity and make sure that you keep a record of it so that you can compare the results to the measurements of the new water which you’re going to add…if there is too much of a difference, you may find that your more delicate inhabitants are shocked by the change or sometimes even killed.
If you are going to introduce any new equipment to your routine then it’s a very good idea to soak it in salt water before immersing it in your tank and remember that while water can evaporate from tanks, the salts don’t disappear….so even if there appears to be less water in your tank before you change the water, there is not less salt…so don’t add salt water to your tank or you could risk upsetting the levels significantly.
Keeping an aquarium might seem like a complex business at times but it’s also extremely satisfying and rewarding…the water quality is everything so be careful to follow the recommended actions when it comes to water changes and keeping things on an even keel.
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