Raising Brine Shrimp to Adult size

Many pet shops sell live adult brine shrimp (Artemia).  That is fine if you live near a pet shop. The closest one to me that sells adult brine shrimp is about an hour’s round trip away. At about $2 a bag and 2 gallons of gas, it just does not make sense for me to buy live shrimp. 

I have had success raising brine shrimp to adulthood outside.  Growing your own brine shrimp is cost effective even if you don’t have to make a long trip to buy them.The first step is finding a suitable container.  

The 3-4’ plastic children’s wading pools can produce large quantities of brine shrimp. The problem is that they are very shallow. If you get several inches of rain they will over flow and dilute the salt water the shrimp live in. This usually kills the shrimp. Use the wading pools if  your climate does not have heavy rains.  

I have switched over to plastic buckets for yard work. They hold about 20 gallons.  I fill them up to about 5” from the top.  A heavy rain will dilute the salt, but it does not over flow and lose the salt. The specific gravity will rise as the water evaporates.  Also, 4” of rain in a 4” deep pool has a much larger effect than 4” of rain in a 15” bucket. Unfortunately the buckets are not as productive as the pools. I think this is because of the smaller area to get sun, which helps the algae grow. The Artemia eat the algae.

Find a sunny location for your container and fill with water.  Let it sit for a few days if your water has chlorine or other chemicals. Add in a teaspoon of Miracle Grow and some green water. Over the course of a week or so, add salt until the specific gravity reaches about 1.020.  The algae water will adapt to the increasing salt.

Solar salt for water softeners is an inexpensive source of the salt. Don’t use types that have additives for rust.  I usually add some Epsom salts as well.  We have hard well water, but if you have soft water, add some sodium bicarbonate (baking soda) as well.

When you reach the proper specific gravity you can add some baby brine shrimp. I add the dregs from the brine shrimp I hatch to feed baby fish. Even when you are done harvesting the shrimp for your fish, there will typically be hundreds left. You could put eggs directly in the outside pool if you wish but I try to keep the egg shells out of the container. 

In a couple of days, the shrimp loose their orange color and you won’t be able to see them. You will think they died. Have faith. They are probably doing just fine. They will grow enough to see them again in a week or so.  I add more baby brine shrimp ever week or two.  

After about 3 weeks they will reach harvest size.  Use a course net to catch the larger ones while letting the small one through.  

Supplemental feeding with green water is useful. Algae will sometimes form on the sides and bottom of the container. That is great as brine shrimp will scrape it off if they can’t get enough by filter feeding.  

As the brine shrimp grow to adult size they will start to reproduce on their own. If you don’t add more baby shrimp you can sometimes see small shrimp from natural reproduction.  I  don’t think they reproduce fast enough on their own to keep up with harvesting. If you are using hatching water you would otherwise throw out, you can keep a steady stream of adult shrimp for no additional cost.  

As the water gets cooler they don’t grow very much but they will stay alive until the water gets close to the freezing point. Because salt water freezes at lower temperature than fresh water, they last later in the year than daphnia, which I also raise outdoors. Here in south eastern Wisconsin I can harvest until mid-November in most years.  

If you let the container freeze over the winter, there is a good chance the shrimp will reappear in the spring.  I found it is best though to start with fresh water each spring for maximum production.