{"product_id":"fluval-sea-saltwater-levered-hydrometer","title":"Fluval SEA Saltwater Levered Hydrometer","description":"\u003cp\u003e\u003cstrong\u003eTells you your salt level at a glance, without mixing up a refractometer.\u003c\/strong\u003e The Fluval SEA Saltwater Levered Hydrometer is a low-profile, in-tank gauge for marine and reef aquariums — install it once and read specific gravity and salinity as easily as checking a thermometer.\u003c\/p\u003e\u003ch3\u003eKey features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLevered float design\u003c\/strong\u003e — the arm swings against a printed scale as salinity changes, so there's no swirling or waiting for a reading to settle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSlim, low-profile body\u003c\/strong\u003e — sits against the glass rather than floating loose, so it's easy to hide behind rockwork or a return pump.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIdeal range marked in green\u003c\/strong\u003e — a quick visual check without reading exact numbers every time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePermanent or portable use\u003c\/strong\u003e — mount it in the display for continuous monitoring, or dunk it in a sample cup at water-change time.\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\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eLevered float hydrometer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUse\u003c\/td\u003e\n\u003ctd\u003eMarine\/reef specific gravity and salinity\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eIn-tank (permanent) or sample-cup (portable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eSEA04\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eFluval doesn't publish an exact specific-gravity scale range or resolution figure for this model — the printed scale on the arm is the reference, and the green band marks the target zone rather than a numeric readout. If precise, repeatable numbers matter to you (for dosing calcium or alkalinity, for example), pair this with a refractometer rather than relying on the hydrometer alone.\u003c\/p\u003e\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eSuitable for: quick daily or weekly salinity checks on marine and reef tanks, sump or display mounting.\u003c\/li\u003e\n\u003cli\u003eNot suitable for: precision dosing decisions — hydrometers of any design carry more reading error than a refractometer or a calibrated conductivity probe, especially at the edges of the scale.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTarget ranges by setup\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSystem\u003c\/th\u003e\n\u003cth\u003eTypical target SG\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFish-only marine (FOWLR)\u003c\/td\u003e\n\u003ctd\u003e1.020–1.024\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMixed reef\u003c\/td\u003e\n\u003ctd\u003e1.023–1.025\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSPS-dominant reef\u003c\/td\u003e\n\u003ctd\u003e1.025–1.026\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eThese are general aquarist reference ranges, not figures printed on this specific hydrometer — check your livestock's needs and adjust to match.\u003c\/p\u003e\u003ch3\u003eCare and maintenance\u003c\/h3\u003e\u003cp\u003eRinse in fresh water occasionally to clear salt creep from the pivot, which is the main cause of a sticky or slow-moving arm. Check the reading against a fresh calibration sample (or a second hydrometer\/refractometer) every few months — all mechanical hydrometers drift with age and salt build-up.\u003c\/p\u003e\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\u003cp\u003eCovered by Fluval's standard manufacturer warranty against defects, in addition to your rights under Australian Consumer Law. Small parcel item — standard freight.\u003c\/p\u003e\u003ch3\u003eCommon questions\u003c\/h3\u003e\u003ch4\u003eIs a hydrometer as accurate as a refractometer?\u003c\/h4\u003e\u003cp\u003eNo — hydrometers of any design (floating, levered or swing-arm) are less precise than an optical refractometer, and are more sensitive to temperature and calibration drift. They're a good everyday check; use a refractometer if you need repeatable, precise numbers.\u003c\/p\u003e\u003ch4\u003eDoes temperature affect the reading?\u003c\/h4\u003e\u003cp\u003eYes. Specific gravity readings shift with water temperature, so take readings at a consistent tank temperature for results you can compare week to week.\u003c\/p\u003e\u003ch4\u003eCan I use this in a freshwater tank?\u003c\/h4\u003e\u003cp\u003eNo — it's calibrated for the salinity range of marine and reef aquariums and won't give a meaningful reading in freshwater.\u003c\/p\u003e\u003ch4\u003eHow often should I check salinity?\u003c\/h4\u003e\u003cp\u003eWeekly is a reasonable baseline for a stable reef, more often after water changes, dosing adjustments, or if you're troubleshooting livestock stress.\u003c\/p\u003e","brand":"Fluval","offers":[{"title":"Default Title","offer_id":55293311484195,"sku":"SEA04","price":35.95,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/fluval-sea-saltwater-levered-43875501998371.webp?v=1790236916","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/fluval-sea-saltwater-levered-hydrometer","provider":"Nicks AOT","version":"1.0","type":"link"}