Crawdad and Lighting Questions:

[TheIrishJedi]

How long should I leave the tank light on and when should I turn it off? Do fish sleep? Is light 24/7 Unhealthy?

I think I scared my crawdad last night. He usually is out and about all the time, but when I changed the water he went under his broken pot and won't come out, not even to eat (he is alive). My water temp is hovering at 78-80 degrees with the light on. Is this too hot for him?

I also added some tank buddies. 4 ghost shrimp for him to eat and 2 neon tetras. Are they skittish around other fish?

 

[Ruadh]

How long should I leave the tank light on and when should I turn it off? Do fish sleep? Is light 24/7 Unhealthy?

Yes fish sleep, crayfish too, but they are nocturnal. If your tank is planted, you should keep the lighting to 10 hrs or less depending on the plants. If it's not planted, just a few hours a day is plenty.

I think I scared my crawdad last night. He usually is out and about all the time, but when I changed the water he went under his broken pot and won't come out, not even to eat (he is alive). My water temp is hovering at 78-80 degrees with the light on. Is this too hot for him?

The temp might be a copuple of degrees high, not much though.
Are you sure he's not molting?

I also added some tank buddies. 4 ghost shrimp for him to eat and 2 neon tetras. Are they skittish around other fish?

No, they're not skittish unless they're about to molt. He'll eat those fish if he can get hold of them.

 

[gzeiger]

I've had great luck keeping ghost shrimp together with crayfish. I doubt those will end up as food unless they die of other causes. They are also largely nocturnal, active when he is and will be able to avoid him. You may have less luck with other fish, especially if they sleep on the bottom. The best thing to feed crayfish is spirulina discs, but they will eat nearly anything. If you don't mind the look of it, dead leaves in the bottom of the tank gives them a continuous source of forage too.

When you do seem him molt (you'll see what looks like a dead crayfish or skin in the tank) make sure you leave the old shell alone. He'll eat it, soometimes after a day or two. The nutrients in the old shell are difficult for them to replace unless they can eat it, especially calcium.

As far as light, the crayfish will definitely appreciate dark periods, and for the rest of the tank long hours of lights on tend to cause large buildups of unsightly algae on the walls. Unless you have a need to provide light for growing plants, it's best to keep the lights on only during hours when you'll be viewing the tank, or feeding. 6-8 hours a day is a good period for a fish only tank.