Issue With A Zebra Danio

[Alexbarrett2000]

I have had my nano tank cycling for a while now and tested the reading which were all good I decided to add 3 zebra danios as there hardy and wanted to start a cycle but 1 Danio seems to be nuts buzzing around and charger at the 2 others there only 3 relatively Danio in the 30litre tank hut I'm not sure how to tell if this is play or a sign of aggression

There only in the tank to allow a good cycle as the tank will be used for a betta but I k ow there sensitive so wanted to get a real good cycle up before adding him

The reason I asked is in 4 6 weeks depending on cycle I will be moving the danios to a 80 litre tank with some other fish and don't want him to be an asset to them all

 

[Ch4rlie]

Danios tend to do better in much larger groups, 3 is not enough to spread aggression amongst them.
 
But the more pressing issue for me is, are you using these danios as a source of ammonia to do your tank cycle as this is not recommended. I would urge you to return these danio to the store or park them in a friend's or relative's cycled tank for a while.
 
If this is the case and you are cycling your tank then I recommend you follow this cylcling guide for a fishless cycle as this is a much more humane and much easier way, also usually much quicker to complete successfully.
 
Cycling Your First Fresh Water Tank

 

[Alexbarrett2000]

Sorry I have poorly explained myself

I have done a full 6 week fish less cycle and riddled the tank of ammonia and nit

I have used the danio as a shall we say test I have regularly tested the water fish less and took sample to the shop they agreed the cycling is complete I used the danio to improve the cycle with fish as I know bettas are extremely sensitive to make the tank as best as possible I read that danio need to shoul but was told this was a good way to improve the cycle with live fish as I liked danio I chose them as there hardy and I was aware I could move them to my fully established tank when we found the correct betta is weeks to come and added a further 6 to make a total of 9 altho was never aware of any aggression as have always been told there perfect for beginners I now feel I maybe should have opted for neons as the seem peaceful

 

[Ch4rlie]

Ah, thats not so bad in that case then
 
Right, despite being small little fish, zebra danios are a little too active for a 30 litre tank to be entirely honest, I would say a three foot long tank minimum, 80litres / 20 US gals would be more appropraite for a decent shoal of zebra danios.
 
http/www.seriouslyfish.com/species/danio-rerio/
 
 
Imho even these little neon tetras need a little more room than a 30 litre / 8 US gals tank
 
http/www.seriouslyfish.com/species/paracheirodon-innesi/
 
I would say just to stay with just one betta splendens in that tank as they tend not to be very good with any tankmates as they are usually aggressive, 8 US gals is pretty much an ideal size for them.
 
Perhaps you could put in some nice live plants such as anubias and java ferns etc and add some snails and maybe even adult cherry shrimps if the betta will tolerate them. Would make a pretty nice tank to be fair.

 

[Alexbarrett2000]

I only was putting the danios in to continue the cycle when I place the betta I will put them in my other tank

Pfft I was advise danios would be good for the nano and cycle I'm beginning to wonder of its worth it u ask opinions and they give you the wrong info thanks for your reply tho

 

[Ch4rlie]

Unfortunately, that tends to happen at a lot of LFS
 
Usually its down to several things, ignorance, lack of training, saying anything to get prodcucts sold for profit and old school methods which incidently is danios being used for cycling tanks is a old school method as this used to be the normal way of doing things. This hobby has changed an awful lot in the last few years for the better.
 
But I have to say not ALL lfs and staff are like this but at the moment they are few and far between to find good reliable sources.
 
Doing research and asking established fishkeepers for advice is the way to go, just as you are doing now, asking for advice

 

[Alexbarrett2000]

So short term fix for this aggressive danios is?

 

[Ch4rlie]

I would, if suitably matched with others in your other tank put them in there and bump up numbers to at least 6, 8+ being better.
 
And you can add 'snack' doses of ammonia, would say 1ppm max as betta do not have high bioloads, to the 30 litre tank every few days to keep the bacs happy until you get a betta of your choosing.

 

[Alexbarrett2000]

If put in the other tank with 8+ danios would that definitely eradicate the aggressive behaviour or just help as his seems like he on speed buzzing around the tank

 

[Ch4rlie]

It may be down to stress of being in a too small a tank and in a tiny group thats stressing this particular danio out to doing things which may not be of normal behaviour. So, based on that, it would seem more than likelythat this would help spread the aggression in a larger tank as they would be less stressed being in a larger tank and in a more decent numbers.
 
Though of course sometimes you get the odd one out in almost any species which is just an out and out bully but thankully not all that common afaik.

 

[StevenF]

I had purchase 4 zebra Danios years ago and at first they were fine but  over time two became increasing agressive.  I then noticed as one got larger that he was not a zebra Danio.  He probably was a Lepard Danio and eventually go quite large.  Then I noticed the other agressive one was larger than the other 2 zebras and I eventually learned he was a long fine zebra danio.  So out of my purchase of 4 2 were what I wanted and the other two were not.  At that time I decided to change my tank stock and found a fish store that took my fish.  I now know that some of the fish farms are selling to the stores "mixed" zebra danios.  Furthermore at the store they are small enough that it is difficult for the store or customer  to tell them appart.  
 
You might want to take a very carefull look at what you have. 

 

[Alexbarrett2000]

Yes I saw that in pet@home there were selling assorted danios they had zebra golden short and long finned
Also now moved the large bully from the tank to allow the smaller 2 room now the bigger out the to is being a dick