Crawfish in a freshwater aquarium require adequate air flow, which can be provided by using an aerator with tiny holes so they don’t escape. There should be bubbles in the tank at all times and a filter to keep the water clean.
Crawfish are excellent climbers and jumpers. Use a tank that is at least 5 gallons or larger with a 4-inch water depth. Crawfish prefer this water level rather than anything deeper. They also like hiding places that they use as shelter during the day. So use lots of rocks that mimic their natural habitat with plants and gravel. Be careful not to place the rocks too close to the edge where the crawfish can climb and escape.
Crawfish are solitary and like privacy. So it's best not to raise them together in the same aquarium. If more than one is desired, make sure they each have adequate space with separate hiding places, as they are territorial. Limit the addition of large fish as well.
The aquarium water should have a neutral pH level of 7 that should be checked weekly. Boiling an egg and using half its shell crushed into the water helps to maintain the pH level. Drop a tiny amount of fish food in the water twice a day, as crawfish eat very little. They prefer food such as shrimp pellets, vegetables, algae wafers and small fish.
In the wild, crawfish live in swamps, ponds and streams. They are sensitive to, and cannot tolerate, polluted water.