How to Keep Brine Shrimp Alive After Hatching (+ Grow to Adulthood)?

[FishRookie]

My students are trying to grow brine shrimp to adulthood in our classroom, but we've been having a lot of difficulty keeping them alive after hatching. We are using a 1.7 L tank with tap water that has been conditioned. The salinity is around 36-37 ppt measured with a hydrometer. We have a heater set at 77 degrees F. We have a small air stone running (we've tried running it periodically throughout the day for short spurts, running it all day but not overnight, running it all day and night). During the day we have a plant light overhead but this is turned off at the end of the school day. The tank has an opaque lid so there's not actually that much direct light (we mostly use it to make it easier to observe the shrimp and also for our actual plants next to the tank). The eggs are in good condition and not expired. Our best run so far is: Eggs hatching on Tuesday, alive and thriving on Friday, but most dead by Monday after the weekend. We've been trying to feed it some baker's yeast (first mixed with conditioned water in separate container till cloudy, then pipetted into the brine shrimp tank). Basically we've been trying different things and none seems to be working very well. Help and suggestions?

[Guppysnail]

Hi. What a wonderful project. I’m sure the students are fascinated. 
 

Are you doing water changes and measuring for ammonia?  As the shrimp produce waste it poisons the water with ammonia. I can feed from my brine shrimp hatchery for a few days but by day 4-5 any left have perished from ammonia toxicity. They do need air running all the time but once hatched it can be turned down. 
 

Here is a nice read. https://static.fishersci.com/cmsassets/downloads/segment/ScienceEducation/pdf/CarolinaBiological/Brine-Shrimp-CareSheet.pdf

[FishRookie]

Thanks for the resource link and suggestions! So far we have just been topping it up once the water evaporated a bit. We don’t have a tool to measure ammonia unfortunately, but will definitely try doing a water change to see if that helps! Would you suggest shining a light near the bottom, scooping out some water from the top and then adding the replacement water? Is there a better way to do this? My guess is that there’s probably a lot of dead shrimp in the tank too near the bottom. 

[Guppysnail]

I suggest hatching in a soda bottle like this video. There are many videos on YouTube to show variations of this. Find one that’s easy for you or your class to do.  Then removing the live shrimp easily by allowing them to settle to the bottom by shining a light. Use a length of air hose to easily siphon the live brine to your grow out container.  
This separates the brine shrimp from the egg casing that decay and waste left from hatching. It gives the brine shrimp clean water and clean container to grow in and be fed in. 

 

[AllFishNoBrakes]

I’ve never attempted to grow them out, but I agree with @Guppysnail that they’re probably dying due to ammonia build up. They produce waste, just like fish do, and without a cycled/seasoned tank that can convert that waste to nitrate it’s going to be a struggle to raise them. I also agree that they will need air all the time. 
 

Shining a light to the bottom of the grow out tank (as they’re attracted to light) is a great way to lure them to one spot to be able to perform a water change without siphoning them all up. Just like cycling a tank, you’ll want to do lots of water changes to keep the ammonia at bay. Might be tough over the weekend, but I believe that’s your best bet to successfully pulling off this project. 
 

Maybe you could use some Fritz TurboStart (the saltwater version) to help you get through the cycling phase successfully? I’d try either that, or if I knew someone with a saltwater tank maybe they could lend you a filter to squeeze into the tank to get the bacteria you need to convert the ammonia. 

Edited November 19, 2023 by AllFishNoBrakes

[FishRookie]

Thank you so much @Guppysnail and @AllFishNoBrakes! We tried doing some water changes to bring down the ammonia levels and the brine shrimp managed to survive the weekend! They are starting to actually get a little bit larger in size compared to when they first hatched, so this has been exciting for the students. We have continued to feed a little bit of yeast each day and that seems to be going okay so far. If we can keep them alive till winter break, any suggestions for how to manage two weeks where no one will be in the classroom to change the water? Would it be helpful to use the Fritz TurboStart on the last day we are at school, do a good water change, and hope for the best? I have appreciated the tips so much! This is the farthest we've gotten in our brine shrimp hatching adventure so far!

[Guppysnail]

I’m so glad it’s working for you. I’ve never kept brine shrimp to adulthood outside of as a kid. They were sold as Sea Monkey insta pets.

I use this gentleman’s videos on many live cultures. He makes thing simple. It may help. He does have a website that allows questions to be emailed. He may be of assistance for that question.