Lethargic Crayfish

[Banafish]

Hi, my crayfish started showing signs of lethargy yesterday, being slow in the morning and then was lying on its side in the evening (molting?). I tested my parameters:
ph 8.0-8.2
Ammonia 0.5 ppm
Nitrites 0 ppm
Nitrates 0 ppm
20 C

pH was a bit higher than normal (no apparent reason) so I did a 50% water change (52l tank, ~13 gallons) which then became 7.4-7.6.

However, today he is just lying flat and doesn’t seem to be trying to molt anymore and just stays still. There are no other tank mates. Is this an unsuccessful molt? Is there anything I could do to help? Any help/advice is appreciated, thanks

Yesterday:

Today:

 

[gwand]

The presence of ammonia in an alkaline environment is probably the reason.

 

[MaloK]

I agree with Gwand.

The fact that your biological filter may not be fully established indicated by 0 nitrates, is probably causing the issue.

Crayfishes are very delicate creatures and cycling a aquarium with them is extremely difficult. Because even at low level of ammonia and nitrite is still very poisonous for them and their gills gets damaged rapidly.

Both ammonia and nitrite are highly stressful for them and also water changes too, so you are stuck between the tree and the bark.

If you have a product that neutralize / detoxify ammonia and nitrite, it's the time to use it quickly.

 

[Archerfish]

Yes water quality as mentioned above but...after a crayfish molts it will often be very lethargic. Molting is traumatic. Mine used to hide in a cave afterwards for several days.

 

[Banafish]

I agree with Gwand.

The fact that your biological filter may not be fully established indicated by 0 nitrates, is probably causing the issue.

Crayfishes are very delicate creatures and cycling a aquarium with them is extremely difficult. Because even at low level of ammonia and nitrite is still very poisonous for them and their gills gets damaged rapidly.

Both ammonia and nitrite are highly stressful for them and also water changes too, so you are stuck between the tree and the bark.

If you have a product that neutralize / detoxify ammonia and nitrite, it's the time to use it quickly.

Well from the water change I did yesterday the ammonia levels are already down, so is there anything else I could do to help besides observing? Thanks for the help

 

[MaloK]

No, if he is about to molt, the less disturbance the better, even water changes.

Habitually they hide to do it, but since he's the only occupant of the tank, he might be confident enough to do it in plain sight. but it's a critical moment for him.

If he molts successfully, leave the exoskeleton in the tank, he will graze on it until it's gone.

 

[Archerfish]

Looks like it already molted.
52l is a very small tank (about 13 gallons). Suddenly changing half of your water with a radically different pH will negatively affect (shock) the crayfish. I would investigate why your pH crept up. Something caused it to increase and you need to find the source (for example: substrate, aeration, poor water quality, added chemicals etc.) because it will most likely do so again. Avoid doing anything that will shock the crayfish. Do your water changes over a period of hours. Look at it this way, when we bring home fish, we always slowly acclimate them to the pH and temperature of the tank. Do your water exchanges in the same manner.