{"product_id":"red-sea-salts-4-kg-120-ltr-bag","title":"Red Sea Salts - 4 kg (120 Ltr Bag)","description":"\u003cp\u003e\u003cstrong\u003eOur best cost-per-litre pack in the Red Sea Salt range.\u003c\/strong\u003e Red Sea Salt is a premium reef-grade marine salt mix that dissolves fast and clean to a balanced calcium, alkalinity and magnesium profile. This 4 kg bag mixes to roughly 104 L at full reef salinity — enough for a run of water changes on a small-to-mid system — and, litre for litre, it costs less than either the 2 kg bag or the 22 kg bucket we stock.\u003c\/p\u003e\u003ch3\u003eKey features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOne salt, three targets\u003c\/strong\u003e — the same formula mixes to a lighter fish-only salinity, a mid invertebrate salinity, or full reef salinity, just by changing how much you dose. See the mix ratio table below.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDissolves fast and clear\u003c\/strong\u003e — no cloudiness or residue once mixed and aerated.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree of nitrate and phosphate\u003c\/strong\u003e — won't feed algae or push a reef tank off balance.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eMix ratio and resulting parameters\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSystem type\u003c\/th\u003e\n\u003cth\u003eDose\u003c\/th\u003e\n\u003cth\u003eSalinity\u003c\/th\u003e\n\u003cth\u003eCalcium\u003c\/th\u003e\n\u003cth\u003eAlkalinity\u003c\/th\u003e\n\u003cth\u003eMagnesium\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFish-only\u003c\/td\u003e\n\u003ctd\u003e33.4 g\/L\u003c\/td\u003e\n\u003ctd\u003e31.0 ppt\u003c\/td\u003e\n\u003ctd\u003e365–395 mg\/L\u003c\/td\u003e\n\u003ctd\u003e6.8–7.3 dKH\u003c\/td\u003e\n\u003ctd\u003e1,100–1,180 mg\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNon-coral invertebrates\u003c\/td\u003e\n\u003ctd\u003e36.0 g\/L\u003c\/td\u003e\n\u003ctd\u003e33.5 ppt\u003c\/td\u003e\n\u003ctd\u003e390–420 mg\/L\u003c\/td\u003e\n\u003ctd\u003e7.3–7.8 dKH\u003c\/td\u003e\n\u003ctd\u003e1,170–1,230 mg\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoral and reef\u003c\/td\u003e\n\u003ctd\u003e38.2 g\/L\u003c\/td\u003e\n\u003ctd\u003e35.0–35.5 ppt\u003c\/td\u003e\n\u003ctd\u003e415–445 mg\/L\u003c\/td\u003e\n\u003ctd\u003e7.7–8.2 dKH\u003c\/td\u003e\n\u003ctd\u003e1,240–1,320 mg\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eAdd salt to water, not water to salt. Mix vigorously without aeration for 30 minutes to 2 hours until the pH settles at 8.2–8.5, then bring the mix to tank temperature and check salinity with a refractometer before use.\u003c\/p\u003e\u003ch3\u003eWhich pack size is cheapest per litre?\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003ePack\u003c\/th\u003e\n\u003cth\u003eLitres at reef salinity\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e2 kg bag\u003c\/td\u003e\n\u003ctd\u003e~52 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e4 kg bag\u003c\/td\u003e\n\u003ctd\u003e~104 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e22 kg bucket\u003c\/td\u003e\n\u003ctd\u003e~575 L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003eThe 4 kg bag is the cheapest per litre of the three sizes we stock. If you're only topping up a nano tank the 2 kg bag still makes sense, and if you'd rather change bags less often the 22 kg bucket is more convenient — but on price per litre alone, this is the one to buy.\u003c\/p\u003e\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\u003cp\u003eSuitable for fish-only, invertebrate and coral\/reef marine systems — the target salinity changes, the salt doesn't. Not a substitute for Coral Pro Salt if you're chasing higher baseline alkalinity for SPS-heavy growth; the two can be swapped between, but only gradually (max 15% of a water change at a time) because of the alkalinity step up.\u003c\/p\u003e\u003ch3\u003eCare and maintenance\u003c\/h3\u003e\u003cp\u003eStore the sealed bag somewhere dry — a damp storage area will clump the salt before you get to use it. Mix in a clean, dedicated bucket and let the water reach tank temperature before dosing, to avoid a temperature shock on the tank it's going into.\u003c\/p\u003e\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\u003cp\u003eSold as a consumable, not a warranted item beyond your consumer guarantee rights under Australian Consumer Law — if a bag arrives damaged or short-filled, contact us for a replacement.\u003c\/p\u003e\u003ch3\u003eCommon questions\u003c\/h3\u003e\u003ch4\u003eWhy is the 4 kg bag cheaper per litre than the 22 kg bucket?\u003c\/h4\u003e\u003cp\u003eIt comes down to how each pack size is currently priced, not a difference in the salt itself — check the comparison table above rather than assuming the biggest pack is automatically the cheapest.\u003c\/p\u003e\u003ch4\u003eHow much water does a 4 kg bag actually make?\u003c\/h4\u003e\u003cp\u003eAround 104 L mixed to full reef salinity (38.2 g\/L). Mixed lighter, for a fish-only tank at 33.4 g\/L, the same bag goes further — about 120 L.\u003c\/p\u003e\u003ch4\u003eWhat's the difference between this and Coral Pro Salt?\u003c\/h4\u003e\u003cp\u003eCoral Pro Salt carries a higher baseline alkalinity aimed at faster SPS coral growth. Elemental composition is otherwise similar, and you can switch between the two — just do it gradually across water changes rather than all at once.\u003c\/p\u003e\u003ch4\u003eIs this the same formula as the 2 kg and 22 kg packs?\u003c\/h4\u003e\u003cp\u003eYes — identical salt, just a different pack size and price point.\u003c\/p\u003e","brand":"RedSea","offers":[{"title":"Default Title","offer_id":55242298425635,"sku":"BA0232","price":30.0,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/red-sea-salts-4-kg-120-ltr-bag-3000015-1600.jpg?v=1781836191","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/red-sea-salts-4-kg-120-ltr-bag","provider":"Nicks Aquarium Oceanarium Terrarium","version":"1.0","type":"link"}