How Long Do Sea Monkeys Live? Breathtaking Lifespan!

4 min read

Popular since the ’50s, sea monkeys are still enjoyed by children today. Sometimes sea monkeys don’t even hatch and this can be very disappointing but when they do hatch you might be asking yourself: “How long do sea monkeys live?”

Not to be confused with Artemia brine shrimp which only live for an average of 3 months, sea monkeys are a hybrid brine shrimp called Artemia Nyos and can live up to one year.

Sea monkeys consistently breed so a sea monkey colony can last up to five years and sometimes longer if you remove the dead sea monkeys and care for the live ones properly to prolong their life.

The best way to keep your sea monkeys alive for as long as possible is to make sure they have quality water that will prevent disease and optimize their health.

sea monkey life span

How To Lengthen Your Sea Monkeys Life Span and Help Them Live Longer

Just as with fish, we say that we are not actually fish keepers, but water keepers. The key to optimum health for all aquarium animals is to:

  • Clean Water
  • Beneficial Bacteria
  • Proper Temperature
  • Prefered Speed of Water Current

Sea-Monkeys Water Parameters

Aquarium Temp70-80°F
Temp For Hatching80°F
pH Level6.0 – 9.0
Salinity Level30 – 35 ppt

If you have one of the infamous sea monkey kits, then simply follow the instructions that come with the kit which is basically to keep the water topped off with more distilled water with the proper amount of salt.


Easiest way to mix your water is to add 2 tablespoons of non-iodized salt or synthetic sea salt to preferably distilled water but spring or tap water will work. However, since we are talking about optimum health here, you should use distilled water.

If you have your own DIY sea monkey tank then keep reading!

DIY Sea Monkey Tank

Here is the equipment you will need for your sea monkey tank:

  • Sand SubstrateSand substrate is the best but you should rinse it before spreading a thin layer in the bottom of your tank.
  • Sponge Filter Find a sponge filter and heater relative to the size of your tank.
  • Air Stone/Bubbler You can put an airstone – bubbler in your tank to provide more oxygen.
  • Heater Helps to maintain the proper temperature for your sea monkeys.
  • Water Conditioner – When you first fill your tank, you should use distilled water, but if you use tap water make sure you mix in an aquarium water purifier like Prime to remove chlorine and other chemicals from your water.

If you have a large sea monkey tank, you should cycle it for ten days before you put your sea monkeys in it. You can do this by adding some fish food and letting it decompose to add waste to your tank or you can add over-the-counter ammonia.

You can check the water quality with aquarium water test strips.

You can also get a hydrometer to test the salinity of your saltwater to make sure it is in the proper salinity range of 30 – 35 ppt.

When the ammonia and nitrite levels are zero or below 20 ppm, you can add your sea monkey eggs, which you can purchase on Amazon.

You can find brine shrimp eggs at most local pet stores, but the brine shrimp will grow smaller and not live as long as the actual sea monkeys.

Clean Water

To keep your tank clean test the water with test strips once a week and then clean it accordingly.

One of the easiest ways to clean the water is to change 25 percent of the water with clean purified salt water.

You should use a gravel vacuum to clean detritus out of the sand substrate while you are sucking the dirty water out to be disposed of.

Establishing the Nitrogen Cycle

The nitrogen cycle usually takes 4-6 weeks to establish and is done when you set up the new sea monkey tank.

Add ammonia to your new tank to help your filter grow beneficial bacteria which breaks down detritus and waste.

When you have your new tank up and running with ammonia added test the water once a week with test strips.

Most pet stores will test your water for free but call them first to verify that they will do this for you.

Once the ammonia and nitrites are at zero you should be able to add your sea monkey eggs.

Oxygenating the Water

Oxygen in the water helps your sea monkeys grow and stay healthy.

Best way to keep oxygen in your water is to keep it clean and buy an airstone. You can place the airstone anywhere in the tank and it will produce bubbles that help keep the water oxygenated.

Your sea monkeys will produce carbon dioxide after they exhale the oxygen which will cause the oxygen level to drop.

An airstone and regular water changes will help keep oxygen in the water.

Proper Temperature and Salinity

Sea Monkeys are discovered in a wide array of water temperatures but for their best growth, development, and everyday function, the best water temperature is 70 and 80°F (21 to 26.6°C).

If the water temperature is too high or too low, your sea monkeys could become stressed, leading to illnesses.

The easiest way to maintain the desired water temperature is to add an aquarium heater to your Sea Monkeys tank.


This is all you need to know to keep your sea monkeys healthy so they can achieve the longest life span possible.

The most important factors are clean, oxygenated water at the right temperature.

Enjoy your Sea Monkeys!

Written by:

Pet Aquariums

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