Gear
Salt mixes: what reef keepers commonly use
Reef salts, which differ most in alkalinity, calcium and magnesium. Below are 3 items we see often, each with our honest note and where to view it in the UK and the US.
We sell nothing and earn nothing from these links. Prices are as each retailer's page showed them on the date checked, and they change. How this guide works
Listings checked . How we check
What should you look for in salt mixes?
- Alkalinity, calcium and magnesium levels that suit how you dose, then sticking with that salt.
- Switching between a high and a low alkalinity salt moves your tank's numbers, so change slowly.
- Mix in a separate container with a heater and pump, and check salinity before every water change.
Commonly used salt mixes
Specs are as published on the listed pages. Where the US and UK pages give different figures, we show both.
Instant Ocean / Aquarium Systems Reef Crystals
Brand: Instant Ocean (Aquarium Systems)
Our note. A long-established, widely available reef salt with added calcium. It is a sensible low-cost default; published element levels are less detailed than premium mixes.
Key specs
- Bags for 150 US gal (BRS)
- UK box 20 kg (10 x 2 kg), each bag about 55 litres
UK listing
Kraken Corals (UK): opens the retailer's page for Instant Ocean / Aquarium Systems Reef Crystals in the United Kingdom- Price as shown
- £54.99 (20 kg)
- Checked
US listing
Bulk Reef Supply (US): opens the retailer's page for Instant Ocean / Aquarium Systems Reef Crystals in the United States- Price as shown
- US$76.99 (150 gal bags)
- Checked
Tropic Marin Pro-Reef
Brand: Tropic Marin
Our note. A reef salt with natural-level alkalinity and higher calcium and magnesium, popular with keepers who dose. Its lower alkalinity can feel like a drop if you switch from a high-alk salt.
Key specs
- Alkalinity about 7 dKH
- Calcium about 440 ppm
- Magnesium about 1,350 ppm
UK listing
Kraken Corals (UK): opens the retailer's page for Tropic Marin Pro-Reef in the United Kingdom- Price as shown
- £48.49 (10 kg bucket)
- Checked
US listing
Bulk Reef Supply (US): opens the retailer's page for Tropic Marin Pro-Reef in the United States- Price as shown
- US$70.99 (100 gal box)
- Checked
Red Sea Coral Pro Salt
Brand: Red Sea
Our note. A high-alkalinity salt aimed at coral growth in tanks that use a lot of alkalinity. Mixed water changes more in storage than many salts, so mix shortly before use.
Key specs
- Alkalinity 12.3 to 12.7 dKH at 35 ppt
- Calcium 455 to 475 mg/l
- Magnesium 1,360 to 1,420 mg/l
UK listing
Kraken Corals (UK): opens the retailer's page for Red Sea Coral Pro Salt in the United Kingdom- Price as shown
- £67.90 (20.1 kg box)
- Checked
US listing
Bulk Reef Supply (US): opens the retailer's page for Red Sea Coral Pro Salt in the United States- Price as shown
- US$87.99 (160 gal box)
- Checked