Is this a good cray tank?

[knifegill]

I'll watch for that gap, thanks for the tip. The more I know the better. I've got the basics down:
Slightly hard water
Veggies and some pellet food covers most of their dietary needs
Calcium in the water column and as decor just in case
Temp 72ºF
Fine filtration and good water movement
Is there more?
What's the best daylight period? 9 hours?


Hey, one of them looks red but the other three are greenish.

 

[Tanks of Steel]

Edit: Tank looks good btw. Keep an eye on the acrylic lid with that light sitting on it. I've had heat from lights warp acrylic before. If there is a way out a cray will find it.

I have a couple dozen crayfish in my tank (the one in my avatar). They don't climb out the top at all. Open top. I have one cray that is as large as my entire palm from base to finger tips. His claws are 3" long. My cichlids, oscar, jag, and gt, don't go near him. Most of the others can become a snack if they aern't careful. I have large 2"+ rocks for the crays to hide and climb under.

I love to see some one else take such an interest in crays.

 

[Dark Jester]

I have a couple dozen crayfish in my tank (the one in my avatar). They don't climb out the top at all. Open top. I have one cray that is as large as my entire palm from base to finger tips. His claws are 3" long. My cichlids, oscar, jag, and gt, don't go near him. Most of the others can become a snack if they aern't careful. I have large 2"+ rocks for the crays to hide and climb under.

I love to see some one else take such an interest in crays.

I don't think I'd get by without a top. Within a couple hours of first putting them in my tank, one was up on top of my water heater poking at the lid. The smaller ones like climbing up the algae growing on the back glass to try and reach the top too.

I guess if you don't have any airlines or power cords next to the edges of the tank it might be alright. Or if the water level was a few inches from the rim maybe.

 

[Dark Jester]

Is there more?
What's the best daylight period? 9 hours?

Hey, one of them looks red but the other three are greenish.

That's pretty much it. For light, I just have a 2 bulb 24" fluorescent strip light on my 20 Long tank. Comes on around 9 AM and turns off at midnight. With all the rocks in the my tank though, the crays can always go find a dark spot if they want. Most of them are usually out running around even with the light on.

The greenish brown is their normal color I think. The one showing red might have been in some harder water, but even within my tank there is some slight variations in color with them all in the same water. One of the smaller ones has a rust-red color to it, and a couple have some blue highlights on their legs. Soon as I get some babies I'll be testing the water hardness affecting color theory.

 

[knifegill]

Right on. I wonder what a little marine salt would do. I'll wait until I have a few babies around before playing with them too much.

Do you think it would also matter whether the eggs themselves develop in hard or soft water? You might need to have the mother actually create the eggs in water of controlled hardness to affect the color of the new crays. Just a thought.

 

[Dark Jester]

They change color a little between moultings. Mine all started off tan, but the reddish one and the ones with blueish legs started showing the different colors after a couple moults. Interesting thought about the eggs though. Might just continue my experiment until they reproduce in their jars.

I'd be careful with salt. Thought I spotted Ich on one of the guppies I stuck in with mine so I started a standard salt treatment and I don't think the crays took too well to it. They were acting like they were drunk for a few hours until I decided to remove the guppies to another observation tank and did a big water change on the cray tank to bring the salt level back down. I hadn't even raised the heat yet, and only 3tsp salt per gallon isn't much, but it seemed to have a huge effect on them.

 

[knifegill]

Oh, maybe I won't try salt then. Thanks for the heads up.

Some more weak pics.

Am I stuck? Am I not stuck?

The reach

The stretch

And the 'I fell down and am kind of stuck until I do something about this'.

That's all for now. More when they berry or if more questions come up.

They're making caves in the gravel now. Silly buddies.

 

[Dark Jester]

Nice pics. With the hair algae being that thick, you might want to keep an eye on them. They shouldn't get stuck, but just in case.

Just a note as well, they will attack fish even though some sites claim they won't (If you ever think about adding some). I'd added the guppies to my cray tank mostly as a social experiment to test agressiveness. When I got home from work last night, one of the male guppies had a huge chunk taken out of the middle of it's tail. It looks like a Lyretail now. No finrot or anything going on, and it's still swimming around seemingly happy as can be (still trying to get his groove on with the ladies). Since it's just guppies and crays in there, and the guppies aren't really agressive, I can only conclude that one of the crays is responsible.

For the most part they do get along peacefully though. I often see the guppies swimming right alongside the crays with no agressive action from either of them. Apparently the sight of a juicy tail just begging to be snacked on is too much to resist sometimes.

 

[knifegill]

I might try guppies for fun, but couldn't a big female guppy eat a baby cray?

 

[Dark Jester]

I might try guppies for fun, but couldn't a big female guppy eat a baby cray?

Never really thought about that, I guess it's possible. These guppies do manage to swallow 1" pieces of bloodworm. I was more curious if the crays would snatch up the guppy fry, but I guess the reverse could happen as well.

The baby crays stick to the mother for the first week or two though, so they are protected. By the time they drop off they should be large enough that the guppies will leave them alone. Not sure a guppy would willingly tangle with an adult cray to try and snatch a baby. Guess I'll find out eventually.