Planted Tank Obsessed
Join Date: Jul 2012
Location: Los Angeles, CA
Have you been monitoring your tank for temperature fluctuations or ammonia/nitrite spikes?
For temp, you can check once in the morning, once in the afternoon, and then again in the evening.
For ammonia/nitrite spikes, check about 1hr after you feed your shrimp to see if you get a spike. Sometimes the spike is enough to stress the shrimp, and with repeated daily spikes it can lead to death.
Also, keep a look out for any females that are swimming around erratically. They normally don't do that (at least from my experience). Males swimming around frantically is okay since that is pretty typical breeding behavior (they're swimming around for a female that just molted and is ready to breed).
Also, check your CO2 levels... That could be a culprit as well. The CO2 might seem fine ~4 hrs in, but at ~6 or 8hrs it might be getting intolerable for your shrimp.