Fluval Sea Marine Salt Aquarium Water Conditioner, 3-lb bag

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Create optimal ocean-like conditions in your marine aquarium with Fluval Sea Marine Salt Aquarium Water Conditioner. Coral, invertebrates and saltwater fish thrive in conditions that are similar to their native ocean environment. Fluval Sea Marine Salt Aquarium Water Conditioner is professional grade marine salt formulated and blended proportionally to achieve natural seawater concentrations. It dissolves quickly without residue and contains no impurities and is phosphate- and nitrate-free.

Key Benefits
  • Fast-dissolving - establishes a natural saltwater environment, similar to seawater, quickly and easily.
  • Achieve ideal marine pH level (8.1 - 8.2) right out of the package – ideal for reefs and marine aquariums, and helps avoid coral stress during routine water changes.
  • Enriched Magnesium levels (1250 - 1300 ppm) efficiently absorbed by corals for greater growth potential. High Calcium levels (460 ppm at a S.G of 1.023) for greater development and maintenance of strong coral skeletal structures.
  • Ideal Strontium concentration range (8 - 12 ppm) supports coral tissue growth and skeletal structure.
  • Unique small-batch production process - proprietary trace element mix for consistent results that are free of phosphate and nitrate.

HAZARDS TO HUMANS: Keep out of reach of children. If swallowed seek medical advice.

See all items by Fluval

  • Item Number
  • Aquarium Type
  • Fish Type
    Marine Fish

When starting up an aquarium or when performing water changes: 1. Mix the Fluval Sea Marine Salt with water. Pour the appropriate amount of salt (0.3 lb per 1 US gallon; 36g/L) into a clean bucket with water, preferably de-chlorinated water or reverse osmosis water. Mix salt and water thoroughly using a power head or suitable submersible pump. 2. Measure Salinity: Using a hydrometer, measure the specific gravity. To increase salinity, add more Fluval Sea Marine Salt. To decrease salinity, add more water. 3. Gently pour water into aquarium. Important: Do not pour salt directly into inhabited aquarium. Store salt in a cool, dry place, from from any sources of heat or sun light. Make sure the salt is stored in a tightly sealed container or bag.


Specific GravityDoseSalinity (ppt)Calcium (ppm)
1.02136 g/L31.4425
1.02339 g/L34.0460
1.02543 g/L36.7490

My salt mixing buckets have beige-colored deposits on the sides. Why?

This is likely attributed to using tap water or high alkaline water, which can cause some precipitation when mixing with salt. It is not a problem attributed to the salt, unless you see waste material or discoloration within the salt itself.

After adding salt to my reef aquarium, the specific gravity reading from my hydrometer was very high. What should I do?

Make sure you tap the hydrometer thoroughly to dislodge any air bubbles from the armature. If tapping doesn't help, insert a thin object in the hydrometer and tap the armature directly to release any lodged bubbles.

I just started using Fluval SEA Marine Salt, and I noticed my pH is 8.1 to 8.2 after a few minutes of mixing. I use RO water and the water is clear after that short mixing time. Can I use the resulting marine mix within the first 10 minutes?

Yes, you can. Fluval SEA Marine Salt mixes clear in the first few minutes, and should give you a safe stable pH of 8.1 to 8.2.

Rating: 3.6 of 5 stars 3 Reviews 3 Reviews 3.7 out of 5 Stars

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67% Recommend

67% of reviewersrecommend this product

Rating: 3.6 of 5 stars 3.7 / 5

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  • 5 out of 5 stars

    As Described

    By TJUnlimited on Apr 9, 2021

    Does the trick if your tank is only 10 gallons as it only has enough for 10 gallons. However high quality material

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  • 1 out of 5 stars

    rock salt...the bag had a hole.

    By Dick on Aug 1, 2018

    Since sea salt is hydrophilic, the hole in the bag allowed the salt to turn into a rock.

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  • 5 out of 5 stars

    It work very well

    By Pamjam on Mar 11, 2017

    I choose to try this first time I'm glad I did I haven't had to do as much water change my water stays very clear

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