Brine shrimp eggs hatch rate 1 year after opening

[tooManyPumps]

I was not cautious about storage, maybe they got too warm.  But even so,  I'm shocked by the low hatch rate. I'm getting maybe 5% to hatch after 24h in 82F with 1 tbsp of marine aquarium salt per litre.  Last time I used the same approach and I saw more like 80% hatching.

I repeated my process and measurements twice to be sure. Both batches resulted in very few hatchings despite all parameters being correct.

Edited January 27, 2023 by tooManyPumps

[Guppysnail]

Try letting them run 48 hours. I find any eggs I keep longer than 6 months the hatch rate goes way down even stored in the fridge. I freeze them now if I get more than I will use in 3 months. If storage temp was not monitored this will also dramatically lower hatch rate.