{"product_id":"red-sea-seawater-refractometer","title":"Red Sea Seawater Refractometer","description":"\u003cp\u003e\u003cstrong\u003eOne accurate salinity reading is worth more than a dozen rough ones.\u003c\/strong\u003e The Red Sea Seawater Refractometer is calibrated specifically for seawater rather than fresh water or brine, with automatic temperature compensation (ATC) built in, so a reading taken straight from the tank is close to true without needing the sample to reach a set temperature first.\u003c\/p\u003e\u003ch3\u003eKey features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeawater-specific calibration\u003c\/strong\u003e — a generic refractometer calibrated for brine or fresh water can read out by as much as 1.5 ppt on seawater; this one is built and calibrated for the job.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutomatic temperature compensation\u003c\/strong\u003e — corrects for sample temperature against a 25°C reference, though letting the sample sit a few minutes to approach room temperature still gives the most reliable reading.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual scale\u003c\/strong\u003e — reads specific gravity and salinity (ppt) side by side.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA couple of drops is all it takes\u003c\/strong\u003e — no test tube to fill or colour change to wait on.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded calibration screwdriver and pipette\u003c\/strong\u003e — everything needed to zero the unit and take a sample is in the box.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eMeasurement range\u003c\/th\u003e\n\u003ctd\u003e1.010–1.030 specific gravity \/ 20–40 ppt salinity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTemperature compensation\u003c\/th\u003e\n\u003ctd\u003eAutomatic (ATC), referenced to 25°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCalibration method\u003c\/th\u003e\n\u003ctd\u003eZero-point calibration against RO\/DI water, adjusted with the included screwdriver\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eIn the box\u003c\/th\u003e\n\u003ctd\u003eRefractometer, pipette, calibration screwdriver\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\u003cp\u003eSuitable for any marine or reef aquarium where salinity needs to be checked accurately — new water changes, top-offs, and dialling in a fresh salt mix. Not a substitute for a proper calibration routine: even with ATC, a refractometer calibrated weeks ago will drift, so re-zero it against RO\/DI water regularly rather than trusting an old calibration.\u003c\/p\u003e\u003ch3\u003eCare and maintenance\u003c\/h3\u003e\u003cp\u003eZero the unit against a drop of RO\/DI water before each session, or at minimum every few weeks with regular use. Wipe the prism dry with a soft, lint-free cloth between readings — salt residue left to dry on the prism is the most common cause of a drifting reading. For the most repeatable results, calibrate against a 35 ppt reference fluid if you have one, rather than RO\/DI water alone.\u003c\/p\u003e\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\u003cp\u003eCovered by your consumer guarantee rights under Australian Consumer Law. This is a small, well-packaged item that ships standard parcel post.\u003c\/p\u003e\u003ch3\u003eCommon questions\u003c\/h3\u003e\u003ch4\u003eDo I need this if I already have a hydrometer?\u003c\/h4\u003e\u003cp\u003eA swing-arm hydrometer is accurate enough for a fish-only tank but not for reef salinity, where small errors in calcium and alkalinity dosing compound over time. A refractometer reads more precisely and doesn't have moving parts to stick or wear.\u003c\/p\u003e\u003ch4\u003eDoes it need calibration fluid to work?\u003c\/h4\u003e\u003cp\u003eNo — it calibrates against plain RO\/DI water for everyday use. A 35 ppt calibration fluid gives a more precise zero if you want to check it against a known reference occasionally.\u003c\/p\u003e\u003ch4\u003eHow accurate is it?\u003c\/h4\u003e\u003cp\u003eRed Sea doesn't publish a numeric accuracy figure for this model. What it does state is that a seawater-specific calibration avoids the up to 1.5 ppt error seen when a generic (non-seawater) refractometer is used on saltwater.\u003c\/p\u003e\u003ch4\u003eDoes it come with a carry case?\u003c\/h4\u003e\u003cp\u003eNot that we can confirm from Red Sea's own specifications — it ships with the refractometer, pipette and calibration screwdriver.\u003c\/p\u003e","brand":"RedSea","offers":[{"title":"Default Title","offer_id":54774152003875,"sku":"RED197","price":125.0,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/red-sea-seawater-refractomet-43876662444323.webp?v=1790239002","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/red-sea-seawater-refractometer","provider":"Nicks AOT","version":"1.0","type":"link"}