keeping a blue crayfish tank cycled

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JohnPaul

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I am strongly considering getting a blue crayfish for my 10 gal tank. The current occupants are 3 killifish which have been quarantined long enough for me to put into my main tank, basically allowing me to free up the 10 gal for whatever I want. And the crayfish looks so cool in the store, I think that is the direction I would like to go.

However, will one of these alone produce enough waste to keep the tank cycled? I have one of those corner box filters, nothing very dramatic, but I know crayfish are very sensitive to ammonia/nitrite and so I am wondering if the tank will un-cycle if I put in a crayfish with nothing else.

Anyone have a species tank with these guys who can comment?
 
Bacteria feed off of the waste from whatever is in the tank. Right now, there is enough bacteria to accomidate your 3 killifish. Once you take them out, and there is no waste being produced, the bacteria start diying off. If you put a crayfish in, he will produce waste for the bacteria. There won't be as much bacteria as there were for the 3 killifish because less waste = less bacteria, but it will still be enough to take care his waste. My thoughts are kind of jumbled, but you understand what im saying?
 
Yes actually that made a lot of sense. I was approaching the situation from the standpoint of, if one crayfish produces less waste, then some of the bacteria will die...and thinking that was a bad thing. But you are right, enough will remain alive to handle the waste being produced, so all will work out.

Thanks!
 
but I know crayfish are very sensitive to ammonia/nitrite and so I am wondering if the tank will un-cycle if I put in a crayfish with nothing else.
No offence, but thats crap..
"crays" as u refer to them live in anything..
they're a pest..
u don't even need to cycle ur tank, just throw the bugger straight into tap water
as long as it has oxygen and food, they'll survive.
im giving away 7 at the moment, they ate my feeders in qt
either that or ima kill them
 
DeFeKt said:
but I know crayfish are very sensitive to ammonia/nitrite and so I am wondering if the tank will un-cycle if I put in a crayfish with nothing else.
No offence, but thats crap..
"crays" as u refer to them live in anything..
they're a pest..
u don't even need to cycle ur tank, just throw the bugger straight into tap water
as long as it has oxygen and food, they'll survive.
im giving away 7 at the moment, they ate my feeders in qt
either that or ima kill them


8O Im not gonna even touch this one! :lol:
 
As aquarists, we should always strive to give our pets the best possible living conditions, not the minimum needed to survive in. Also, I am sure that this is an ornamental crayfish which I would assume is a bit more sensitive to water parameters. Either way, in the states I believe that these crayfish do not come cheap.
 
i see ur point..however.
if a feral dog was killing ur livestock, what do u do.
a. relocate it and let it kill somewhere else.
b. capture it and keep it in a cage to die a miserable death.
c. kill it.

forgive my ignorance on the cray subject.
 
This is a thread pertaining to a user wanting to keep a wild creature in their home to the best of their ability. It is not about the user wanting to release their pet into the wild where it will cause damage (releasing fish is something we really frown upon around here), or about punishing something that they see as a pest. Please keep this discussion on topic, or further action will be taken.
 
We are discussing it!

Don't know how it is in Australia, but here crays are sold in LFS as an aquarium invert to be kept like any other aquarium inhabitant, and it is assumed that you would take as good care of them as you would your prize angelfish. They are not sold like feeder guppies (which are kept in less than optimal conditions on the assumption that they will become lunch) and crays are not considered a pest here.

You make a good point about plants - they will tear them to shreds - and the only drawback to keeping one for the purpose of maintaining a cycled tank is that whenever you need the tank again for quarrantine you won't likely be able to throw in your new fish with this cray, as it will do its best to eat the fish. I have had success with blue crays only in species tanks.
 
Like all inverts, crayfish are extremely sensitive to clorine, chloramine, ammonia, nitrite, nitrate, and metals. They also require highly oxygenated water, or they will drown - they do best in an unheated tank with lots of surface agitation.

Crays are scavengers and ambush predators. If they are placed in a tank with fish, it is only a matter of time before they kill and eat them. Even fast fish sleep! Getting angry with the crayfish makes no sense, because that is what they do. They really belong in a species only tank.

Anyway, to answer the poster's question, keep the killifish in the tank until you get the crayfish, and then transfer them to another tank. The tank will remained cycled. Just be sure to gravel vac once a week, and don't overfeed. My crayfish likes to bury any extra food that is lying around, and this can foul the water over time.
 
your right,Great site that.
u know, if u ADD a little bit of chlorine, emphasis on "little bit"
u can turn brown ones to blue ones
they're not as fragile as sum may think...
however, i also see from an aquarist point of view, and can relate to keeping them in as sound an environment as possible..i do so with my fish..
Out of all creatures that i have come across,, i'd have to say that crays are the most adaptable and accepting to any sort of environment change, and i feel that it is a part of there genetic makeup to evolve into these circumstances..

on the note of keeping them with fish, i'm not sure about killifish, i've never had any, but i have a large and a small cray (male and female) in with my oscars and barra's, and they have never had a quarrell. They seem to know where the food comes from, and none have a problem with that..

Interesting story:
Every night, without fail, big boy cray comes out and sits on the pump inlet to the tank.
Every night he wakes me up by tapping on the glass, sounds like a coin tapping on the lid of the tank..
Thats how i know when he wants dinner and he gets rewarded with a block of blood worms, which he takes into his cave an shares with "the missus"
bad habit i know, but its to cool to pass up!!
 
I used to have one in a 35 gal with a 5" oscar, the only inhabitants, and this cray kept that oscar pinned to an upper corner 24/7! That experience has influenced me on how I keep them, but maybe the cray was not adequately fed, and your comment, DeFeKt, about them knowing where the food comes from, may have played a role then - I can't recall what I fed it, but I assume it was some sort of sinking pellet.

I also recently kept one in a 6gal Eclipse tank that had some white clouds in it, keeping it cycled for me, and I decided I'd see if they were fast enough, and keeping enough to the surface of the water to stay away from the cray. Well, the cray placed himself up on some rocks and constantly waved his claws around, hoping one of them would swim close enough. This was obviously too small a tank for them to be together so I removed the minnows.
 
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