Filtration

FILTRATION – Crays can be dirty, especially in increasingly large colonies. Filter these tanks with DOUBLE the appropriate size filter – bigger is better.   The ideal setup would include an undergravel filter, plus an added canister filter. The undergravel filter is very important to maintain a clear cray tank. (Many pet store employees will “poo poo” the need for an undergravel filter. Yes, there is maintenence involved with undergravel filters, but crays are not fishes and do not benefit from a fish-oriented setup). With an undergravel filter, you can mix fine-gravel size charcoal into the substrate, which has the same benefits as charcoal in your canister filter. As for the canister filter, get one that is rated for DOUBLE your tank size. I sometimes put HYDROTON in my canister filters, let them run a month, and you have perfect growing medium for an Aquaponic Garden.

Some people experience crays finding a way to climb OUT of the tank. This is a clear indication that there is NOT enough oxygen, and probably not enough water movement via filtration. Rule of thumb is to keep water level 2 inches from the top of the tank and have 3X or more filtration than you would use for a normal “community tank”.

Cover the filter intake with a “filter sock” (sometimes called a Bonded Foam Sleeve). . Filter media bags from the pet store work great for tube intakes! This will prevent newborn babies from getting sucked into the filter, and since it collects waste and food, serves as a feeding station for all size crays.  You will want to do a partial water change once a week in a cray colony. Even with the best filtration, with molting and normal excretions, a tank of clear water will go yellow in a few days or a week in a large colony (without an undergravel filter and substrate). Changing out up to 90% of the water each week can be considered normal, if you like a nice clear aquarium, and do not have the undergravel filter. Otherwise, change out HALF the tank water every 2 weeks to avoid buildup of ammonia, nitrates etc.

Start the “breeder tank” out with several specimens. (Babies or young adults are the best to start with, rather than larger adults of questionable age). Once your crayfish begin having babies, it simply is a matter of time before you have many generations of crays creating an ongoing supply.

The statements provided in this website reflect the personal experience of the owner, not the results of academic research per se