Hatching brine shrimp is straightforward: add eggs (cysts) to warm saltwater, provide aeration and light, and you’ll have live nauplii in 18 to 24 hours. The process requires minimal equipment, and once you’ve dialed in the right salt concentration and temperature, hatch rates become very consistent. Here’s everything you need to get it right on your first try.
Equipment You Need
The simplest hatchery is an inverted 2-liter soda bottle with the bottom cut off, placed upside-down in a holder or propped in a cup. The cone shape keeps eggs suspended in the water column and makes harvesting easy, since hatched shrimp collect at the narrow bottom. You’ll also need a small air pump, airline tubing, and a coarse-bubbling air stone. The air stone sits at the bottom of the cone and serves two purposes: it delivers oxygen and keeps the cysts tumbling so they don’t settle and suffocate.
Beyond that, you need a light source (a desk lamp or clip light works fine), non-iodized salt, a thermometer, and a fine mesh net or piece of cloth for harvesting. That’s the whole setup.
Getting the Saltwater Right
The target is 25 parts per thousand (ppt), which translates to roughly 1.5 to 2 tablespoons of non-iodized salt per liter of water. If you have a hydrometer, you’re aiming for a specific gravity of about 1.018. Brine shrimp are tolerant creatures, so anything between 1.011 (15 ppt) and 1.030 (40 ppt) can work, but 25 ppt consistently produces the best hatch rates.
Use aquarium salt, marine salt mix, or plain non-iodized table salt. Iodized salt contains additives that can reduce hatch rates. Rock salt and sea salt both work as long as they don’t have anti-caking agents.
The pH of your water matters more than most people realize. Brine shrimp eggs need a pH above 8.0 to hatch well. If your tap water runs acidic (below 7.5), add half a teaspoon of baking soda per quart of water before you start. If the pH drops below 7.5 during incubation, add another teaspoon of baking soda to bring it back up.
Temperature and Light
Keep the water between 26 and 30°C (roughly 79 to 86°F). At the warm end of that range, most eggs hatch within 18 hours. At room temperature (around 72°F), hatching still happens but takes closer to 24 hours or longer, and hatch rates drop. A small aquarium heater or simply placing the hatchery near a warm spot in your home can keep things in range.
Light plays a real role in triggering the hatching process. Aim for continuous illumination during incubation, about 2,000 lux, which is roughly what you get from a standard desk lamp positioned 4 to 6 inches from the container. The light also becomes your most useful tool when it’s time to harvest.
Step-by-Step Hatching Process
Fill your hatchery with the prepared saltwater and let it reach the target temperature. Add brine shrimp eggs at a rate of about one teaspoon per liter of water. Drop in the air stone and turn on the pump. You want steady, vigorous bubbling that keeps every egg in motion. Position your light source near the container and leave it on.
For the next 18 to 24 hours, there’s nothing to do. Don’t feed anything, don’t adjust the water, and don’t turn off the air. The cysts will hydrate, swell, and eventually split open to release tiny orange nauplii. Not every egg will hatch. Hatch rates depend on the age and quality of the cysts you purchased, but a good batch typically produces a dense orange cloud of nauplii.
Harvesting and Separating
Once hatching wraps up, turn off the air pump and remove the air stone. Shine the light toward the middle or bottom of the container. Newly hatched nauplii are attracted to light and will swim toward it, while the empty shells float to the surface. Unhatched eggs tend to sink to the very bottom. This natural separation gives you a clean layer of live shrimp to siphon off.
Wait about 10 minutes for the layers to form clearly. Then use a length of airline tubing to siphon the nauplii from the illuminated zone into a fine mesh net or brine shrimp sieve. Rinse them briefly with fresh water to remove excess salt before feeding them to your fish. Freshly hatched nauplii are at their most nutritious in the first few hours, so feed them promptly or refrigerate them in a small container of salt water to slow their metabolism.
Decapsulating Eggs for Cleaner Hatches
Decapsulation is an optional step that dissolves the hard outer shell of the cyst before hatching. This eliminates empty shells entirely, which is useful if you’re feeding very small fry that might choke on shell debris. It also slightly improves hatch rates because the nauplii don’t have to fight their way out of the casing.
The process uses household bleach. Soak one pound of dry eggs in one gallon of fresh water for one hour to hydrate them. Then add one gallon of non-fragranced household bleach (the standard 5% chlorine concentration). Watch the color of the eggs rather than the clock. They’ll shift from brown to orange to bright orange as the shells dissolve. Once they’ve turned uniformly orange, pour them through a fine net and rinse thoroughly under running fresh water until you can’t smell any bleach. The decapsulated eggs can then go straight into your hatchery or even be fed directly to fish without hatching.
Common Problems and Fixes
Low hatch rates usually come down to one of four things: old eggs, insufficient aeration, wrong temperature, or low pH. Brine shrimp cysts lose viability over time, especially if stored in warm or humid conditions. Keep unused eggs sealed in the refrigerator or freezer.
If you’re seeing lots of unhatched eggs after 24 hours, check that aeration is strong enough to keep every cyst suspended. Dead spots where eggs pile up on the bottom will always produce poor results. Also verify your water temperature hasn’t dropped below 78°F overnight, and test the pH to make sure it hasn’t drifted below 7.5.
Cloudy, foul-smelling water after hatching usually means you added too many eggs for the volume of water. Scale back to one teaspoon per liter and increase aeration. If you’re in a pinch and the water smells off but nauplii are alive, harvest them quickly, rinse well, and feed immediately.