hydrometer vs refractometer aquarium
I own both (an Instant Ocean hydrometer, and an Ebay refractometer) and, honestly, I use both. And considering a good entry-level refractometer doesn’t cost a whole lot more, I personally cannot recommend a hydrometer for everyday aquarium use. To me that seems like a HUGE! Hydrometers – understand the calibration temperature requirements, and take note that S.G. is not a constant number across all measuring equipment and reference sources. Simply place tank water in the hydrometer and the arm will point to the salinity level. To do so you will need either a hydrometer, such as the Coralife Deep Six Hydrometer, or a refractometer, such as the Red Sea Seawater Refractometer. For professional results consider a portable refractometer or a high tech electronic salinity monitor. Aquarium Hydrometers & Refractometers How to use a hydrometer A swing arm hydrometer offers basic salinity testing. MarineAndReef.com: Aquarium Hydrometers Vs. Refractometers. Handheld salinity refractometers (analog) This is the cheapest and most commonly used aquarium refractometer. Before changing your aquarium water, measure and record the specific gravity. The Hanna Salinity tool ($70) has a lot of good reviews, I haven't used it personally though. Long story short, my salt ratio is all messed up now due to the hydrometer being way off. This is a good pick if you want better measurement results. Refractometers are generally more accurate, but do need to cleaned with RO and calibrated and a fairly small bump can throw them off. Make sure the new saltwater matches the specific gravity of your aquarium. While all refractometers do the same job, some do so through digital or analog means. Most hobbyists use a simple hydrometer or a refractometer to measure salinity. I know exactly how much salt to mix into my water change water, and I use a precision scale to measure the dry salt, so I don't even usually test the water before I add it into the tank. Hydrometers can be skewed by micro bubbles, calcium buildup, etc. Compared to a hydrometer, a refractometer is more expensive but generally smaller, more accurate, and uses a smaller amount of liquid. Simply calibrate the refractometer, add a couple drops of aquarium water to the refractive prism and stare into the eyepiece like a pirate to get the salinity reading. So now next WC I will have to only use the refractometer and figure out exactly how much salt to mix. Bubbles on the swing arm can give a bogus reading. Digital vs. analog. When I finally got the water dialed in, the refractometer read 1.025 and the hydrometer read 1.020. Refractometers – understand the calibration requirements and apply an offset to measure the true seawater salinity if using a saltwater/brine model. I have a huge difference between hydrometer and refractometer readings (1.010 hyd vs 1.020 ref)… batch is now 7 days on primary… Hydrometer is calibrated at 60F and Refractometer at 68F, so temperature is not the issue for such a big difference… If one doesn't throughly clean it after use crud can build up on the pivot point, causing a bogus reading. 1. I don't have a refractometer but I am aware of the potential faults of the hydrometer. Every saltwater aquarium requires a testing instrument to measure the salinity (salt level) of the water. difference. Go with the refractometer. If you want to make up your own mind or want a backup way to measure salinity then my top pick, the American-made Instant Ocean Hydrometer is as good as it gets. Reef salinity is typically between 1.024 and 1.026 specific gravity.