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How to Change the Water for Sea Monkeys

By Judith Willson

Sea-Monkeys might be hardy little animals but they still require basic care. As well as feeding your brine shrimp, you may need to keep the habitat clean, which involves changing some of the water. This doesn’t mean scooping out some water and filling up the tank or container from the faucet, which would almost certainly kill the brine shrimp. The correct procedure isn’t all that difficult, though.

Step 1

Prepare a seawater-strength solution in a plastic bucket, not a metal one. Measure out as much distilled or at least dechlorinated water as you think you’ll need, allowing a little extra. Stir in aquarium salt mix as per the instructions, usually about a half-cup per gallon of water.

Step 2

Scoop out water from the tank or container. Pass it through the aquarium net into the measuring jug. If you have accidentally scooped up some brine shrimp, put the net back into the tank to release them. Continue until you have removed about a third of the water.

Step 3

Fill up the tank with the saltwater solution using the measuring jug. Use the exact same amount as you scooped out. If you need to also top up the water level, use plain distilled water for this purpose.

Step 4

Repeat the process after a few days if the water remains cloudy.

Items you will need

  • Bucket
  • Measuring jug
  • Distilled water
  • Aquarium salt mix
  • Plastic stirring spoon
  • Plastic cup
  • Small aquarium net


  • 💡 Note that if you just want to replace water that has evaporated, top up the tank with distilled water. Salt does not evaporate, so continuously topping up with a saline solution would eventually lead to toxic levels of salt in the tank.
  • 💡 The reason for using distilled rather than tap water is because tap water contains chemicals lethal to brine shrimp. It almost always contains chlorine and sometimes chloramine. It is possible to remove chlorine yourself: Just fill a bucket with water and leave it for 24 hours. If your water supply contains chloramine -- check online -- you will need a product designed for this purpose, available from aquarium supply stores.


Judith Willson has been writing since 2009, specializing in environmental and scientific topics. She has written content for school websites and worked for a Glasgow newspaper. Willson has a Master of Arts in English from the University of Aberdeen, Scotland.