New (7) from $12.93 Sold by Awesome Industries, LLC and Fulfilled by Amazon. Instant Ocean SeaTest HydrometerDetailsInstant Ocean Sea Salt FREE Shipping on orders over . Instant Ocean Hydrometer`s new improved design delivers precise full-range salinity and specific gravity readings - accurate to 0.001 - every time. Easy-fill convenience keeps hands dry when filling. It has a durable, permanent needle mount and easy-read 2-color scale with "safe zone" and an extra-wide stabilizer base. Ideal for use in water temperatures of 68 - 85°F. 6.3 x 4.2 x 1.3 inches ; Shipping Weight: 3.2 ounces (View shipping rates and policies) Item model number: tk504 #12,136 in Pet Supplies (See Top 100 in Pet Supplies) in Pet Supplies > Fish & Aquatic Pets > Aquarium Test Kits Compare to similar items API Saltwater Master Test Kit API Reef Master Test Kit API 5-IN-1 TEST STRIPS Aquarium Water Test Strips 25-count 5 star51%4 star17%3 star8%2 star8%1 star16%See all verified purchase reviewsTop Customer ReviewsInstant ocean seatest hydrometerAccurate when used carefullySeems to work,, watch out for air bubbles and might read a little on the high sideInstant Ocean hydrometer is probably the best I've used.

Best there is, I have used this brand for many years.Decent measurement toolworksNot worth it. See and discover other items: protein skimmers for saltwater aquariums Used & new (7) from $10.34 Over 10 million products shipped to more than 100 countries with Amazon Global. See where we ship Fluval Sea Hydrometer for Aquarium, Medium Buy Used and Save: Buy a Used "Fluval Sea Hydrometer for Aquarium, Medium" and save 36% off the $10.66 list price. Buy with confidence as the condition of this item and its timely delivery are guaranteed under the "Amazon A-to-z Guarantee". See all Used offers. Fluval Sea Hydrometer provides an accurate and convenient method of measuring specific gravity and salt level in marine aquariums. Regular testing is strongly recommended as stable salinity levels are essential for the health of marine fish and invertebrates. Compact and easy to use, the hydrometer can be permanently installed inside the tank for continuous readings.

Its slim, low-profile design camouflages well inside the tank and will not diminish the aesthetics of the aquarium. It can also be used as a portable device, allowing you to take samples simply by submerging it in the water. buy aquarium live rockThe Fluval Sea Hydrometer features large, easy-to-read markings with ideal salinity range clearly marked in green for clarity.buy fish tank water pump 1 x 5.5 x 7.9 inchescheap jellyfish aquarium Shipping Weight: 2.4 ounces (View shipping rates and policies) Item model number: 14356 #45,464 in Pet Supplies (See Top 100 in Pet Supplies) in Pet Supplies > Fish & Aquatic Pets > Aquarium Hydrometers Coralife Energy Savers ACLAF877 Deep Six Hydrometer

Portable Automatic Temperature Compensation Salinity Refractometer for Aquarium, Hydrometer, 0-100ppt & 1.000-1.070 Salinity Specific Gravity Coralife BioCube Mini Aquarium Hydrometer 5 star25%4 star8%3 star21%2 star13%1 star33%See all verified purchase reviewsTop Customer ReviewsPut it in vinegar before actual useThis product didnt work as described. i have other ...HydrometerThis fluval hydrometer is not the best. After a couple uses it started to get ...You get what you pay for!Algae CatcherLove having it just sit on the side of the ...ok this is cheap to take salt measurement. New (5) from $20.50 Magnum Media Salinity 10ATC Sold by Golfa and Fulfilled by Amazon. Specifications for this item Professional Automatic Temperature Compensation Sea Water Salinity Refractometer for Aquarium, Hydrometer, 0-100ppt & 1.000-1.070 Salinity Specific GravityDetailsAPI Reef Master Test Kit FREE Shipping on orders over . Resale Quality - 50% heavier than the soft case cheap units

Dual Salinity Scale - 0-100ppt & 1.000-1070 Salinity SG Local stock for fast shipment Brand new Salinity Refractometer that is used to measure the salinity levels of saltwater aquariums and the worlds oceans. Calibrate with either distilled water or a 35ppt Salinity standard. Wipe off the saltwater after each use. This unit comes with Automatic Temperature Compensation or "ATC". This feature allows you to get a reading outdoors when the temp is between 50'F-86" (10'C-30'C). If you test outside of temp range your readings will become gradually more and more inaccurate. For best results, test indoors. No batteries necessary as you only need strong light - daylight (sunny or cloudy) or a lamp/flashlight. 8.1 x 3.2 x 1.7 inches Shipping Weight: 8.8 ounces (View shipping rates and policies) #2,357 in Industrial & Scientific (See Top 100 in Industrial & Scientific) 5 star76%4 star12%3 star4%2 star1%1 star7%See all verified purchase reviewsTop Customer ReviewsNot as flashy as an electronic CTD unit, but simple and reliable for measuring salinitySolid Product Solid Customer serviceWorks like the ad statesEasy to use, quality refractometerPretty goodGood workingFinally a working refractometer!

Most Recent Customer ReviewsSearch Customer ReviewsSide Refine PanelTypesee allWater Typesee allMeasured/Controlled Parametersee allBrandsee allAnalog/Digitalsee allConditionsee allPrice$-$Buying Formatsee allItem Locationsee allDelivery Optionssee allShow onlysee allMore refinements...Got one to sell?Get it in front of 160+ million buyers. It goes without saying that salinity is the most fundamental parameter in a saltwater aquarium. Without salinity, it isn’t saltwater. Yet, perhaps precisely because salinity is such an important parameter, it is often overlooked. This article will explain what salinity is and why it is important to measure salinity. Then, we will discuss what your salinity level should be, and how to test for it. Salinity is the measure of dissolved salt content in water. Salinity is typically measured in parts per thousand (ppt) or specific gravity (sg). The more salt in your water, the higher your readings will be. Saltwater aquarium salinity is usually kept between 1.020-1.028sg.

Some aquarists like to keep fish only aquariums at lower levels (1.017+) to keep salt costs low and to reduce problems with parasites, which don’t survive as well in lower salinity. Many reef aquarists like to maintain salinity at higher levels, sometimes as high as 1.031 because salinity tends to be higher around a reef. Choose what is right for your aquarium, and make sure it stays stable. An auto top off systemcan alleviate your troubles if evaporation is causing your tank to fluctuate a lot day to day. Salinity should be checked very regularly. Oceans are very stable environments, where there is not a lot of day to day change in the water parameters. Fish can respond negatively to even small changes in salinity. So, if you have let your salinity get out of whack, make gradual changes. Then, redouble your efforts to keep everything steady. The most economical way to measure salinity is a hydrometer. There are two basic types: glass models and plastic boxes. A glass hydrometer floats in the water.

The glass tube will sink to a certain level, depending on the density of the water. You then read the measuring line on the tube. If you use one of these models, please do your testing outside the tank. Water flow makes it impossible to measure accurately in the tank. Beyond that, glass breaks. You do not want a broken hydrometer spilling glass and innards into your precious tank. Fill a drinking glass with tank water and test that way. Twenty years ago, glass hydrometers were the standard, but are rarely used anymore. A box hydrometer is a plastic device with a swing arm in it. When the box is filled with saltwater, the swing arm rises to a certain point, depending on the salinity. Box hydrometers are inexpensive and easy to use, but often inaccurate. If the swing arm is corroded or has dried salt on it, the measurement may be off. Most boxy hydrometers cannot be calibrated. When you are looking for stability and accuracy, this can be a problem. As you can see, the low cost of these models comes with a price.

You will not find many dedicated hobbyists who rely on these devices. With what we pay for livestock, a good refractometer can pay for itself with one prevented death. A good refractometer is a precision instrument for measuring salinity. Without getting technical, a refractometer works by measuring how much light “bends” as it passes through the water. As the salinity in the water changes, so does the angle of the refraction, or “bend.” Be sure you are buying a refractometer made for measuring salinity in a saltwater aquarium. Refractometers can be used to measure any number of things, and are calibrated depending on what they were manufactured for. When you buy a refractometer, and periodically afterwards, you should check the calibration of your instrument. You can use salinity calibration fluid,  or you can use distilled or RO/DI water, which should measure 1.000sg. When purchasing a refractometer, you may want to consider a unit with automatic temperature compensation (ATC).

Specific gravity changes depending on temperature. A unit with ATC specifically made for aquarium use will be the most accurate choice. To use a refractometer, place a few drops on the glass plane and then place the clear cover over the sample. Point the refractometer at a bright light source, like your tank. Look through the eyepiece in the back to get the measurement. Your salinity is wherever the colored half of the viewfinder stops. Now, if looking through an eyepiece feels a little too 20th century for you, then you might want to consider a digital refractometer. Digital refractometers work on the same principle as mechanical models, but are more precise. A digital refractometer can also provide readings in the newer standard Practical Salinity Units (PSU) as well as PPT and S.G. You simply drop a sample in the test well on the unit, and it reads you back the salinity. These models are highly accurate and are not significantly more expensive than mechanical models. There are other digital devices to measure salinity as well.