Petshrimp.com Discussion Forum

Have 2 crays in last two days now laying side in tank. They're still alive and occasionally start trying to swim. Remaining 3 are calmly grazing with no obvious signs of stress. No idea on how to help them, assuming they are having trouble moulting. Any suggestions?

How are they doing now? You might have observed them right after a moult. Other than that, moulting is not really a problem for any cray or shrimp. It's what happened before molting that makes the animals weak and causes them to die.

Did you test for nitrate? Nitrate poisoning can occur over time, so even though some animals might be ok, others can fall over and die. How big is your tank? If it's about 10 gallons, try to make 50% water changes a week. These animals, along with most shrimp, don't like accumulations of dissolved organic matter in the water.

Sorry taking so long to respond back. Had to go shopping for test kit, since misplaced last one. Nitrate reading showed 40ppm and nitrite almost undetectable. The extra water changes seem to be helping, in that they're starting to recover motor control in their legs. I guess a wait and see, and keep up the water changes for now.

Well, at least we know now one of the possible reasons for your crays' problems. If you can, do 50% water changes every day for the next 4-5 days to get the nitrate down as much as possible. After that you have to do enough water changes to keep the nitrate as close as possible to zero, but under 5 ppm for sure. The best nitrate level for invertebrates is zero.

Sounds like low levels of Dissolved O2. This is critical with crays for moulting.
The water changes would have upped the oxygen levels as well as lower your nitrates which were high.