To make salt water for hatching brine shrimp, dissolve about 1 and 2/3 tablespoons of non-iodized salt in one quart (roughly one liter) of water. This produces a salinity of approximately 25 parts per thousand (ppt), which hits the sweet spot for most brine shrimp eggs. Getting the salt type, amount, and water chemistry right makes a real difference in hatch rates, so here’s how to do it properly.
Choosing the Right Salt
Aquarium salt, sea salt, or non-iodized table salt all work for hatching brine shrimp. The key rule: avoid iodized salt. Iodine and the anti-caking agents found in standard table salt can interfere with hatching and harm the larvae. Kosher salt and solar salt are also fine options since they’re typically free of additives.
If you plan to raise brine shrimp beyond the hatchling stage into adulthood, switch to aquarium-grade marine salt for the culture water. Marine salt contains trace minerals that support long-term health, while basic table salt or kosher salt lacks these elements. For a one-time hatch where you’re feeding the nauplii straight to fish, household salt works perfectly well.
Salt-to-Water Ratios
The optimal salinity for hatching brine shrimp cysts falls between 15 and 30 ppt, with 25 ppt being ideal under most conditions. Here’s what that looks like in practical measurements:
- Per quart (or liter): 1 and 2/3 tablespoons of salt
- Per gallon: roughly 6 and 2/3 tablespoons (about 1/3 cup plus 2 teaspoons)
If you have a hydrometer, you’re targeting a specific gravity of around 1.018. A refractometer is generally more accurate than a hydrometer, which can be thrown off by micro bubbles or calcium buildup, but either tool will get you close enough. Most people hatching brine shrimp at home don’t need a measuring instrument at all. The tablespoon ratio is reliable.
For raising brine shrimp to adulthood, bump the salinity up to 35 to 40 ppt (specific gravity of 1.024 to 1.028). That means roughly 2 to 2.5 tablespoons per quart. Brine shrimp are remarkably salt-tolerant and can survive salinities as high as 240 ppt, but the 35 to 40 ppt range is where they thrive for long-term culture.
Water Quality and pH
Start with spring water or dechlorinated tap water. If you’re using tap water, let it sit out for 24 hours or treat it with a dechlorinator before adding salt. Chlorine and chloramine can kill brine shrimp larvae.
Brine shrimp hatch best in slightly alkaline water with a pH between 8.0 and 8.5. Most tap water falls below this range, so you’ll likely need to add a buffer. A pinch of baking soda per quart of water is usually enough. If your water tests below pH 7 (which is acidic), use about 1/2 teaspoon of baking soda per quart to bring it up. You can also add 1/2 teaspoon of Epsom salt (magnesium sulfate) per quart, which serves as an additional buffer and provides magnesium that supports hatching.
Step-by-Step Mixing
Dissolve the salt completely before adding brine shrimp eggs. Undissolved salt crystals won’t harm anything, but they make it harder to judge whether you’ve hit the right concentration. Warm water (around 77°F or 25°C) dissolves salt faster and also happens to be close to the ideal hatching temperature. Stir or shake until the water is clear and no granules remain on the bottom.
Once the salt is dissolved, add your baking soda and stir again. Test the pH if you have strips or a liquid test kit available. Then add the brine shrimp cysts. Under good conditions (25°C, continuous light, proper salinity), you can expect hatching within 24 to 48 hours.
Adjusting Salinity for Adult Cultures
If you’re growing brine shrimp past the nauplii stage, transfer the hatchlings into a clean container with fresh salt water mixed to the higher 35 to 40 ppt concentration. Use aquarium-grade marine salt for this batch rather than household salt.
As water evaporates from the culture container over time, salinity rises because the salt stays behind while only water leaves. This is the most common mistake people make with long-term cultures. When you need to replace evaporated water, always add fresh dechlorinated water, never salt water. Adding salt water on top of evaporation will push the salinity dangerously high. If you started at 35 ppt and a quarter of the water evaporates without replacement, you’re already approaching 47 ppt.
Feeding Brine Shrimp to Fish
Before dropping freshly hatched nauplii into your aquarium, rinse them under running freshwater to remove the salt and any metabolic waste from the hatching container. A fine mesh net or brine shrimp sieve works well for this. The salt concentration that brine shrimp need to hatch is high enough to affect your aquarium’s water chemistry if you dump it in regularly, and the metabolites from hatching can be harmful to fish.