Help! Zebra Danio Sinking

[Puddles92]

I am doing a fish in cycle, I know it was a mistake but my little sister wanted to choose the fish and I don't see her very often so we got 2 zebra danios as the store recommended.
The tank had been set up for a week before we got them.
We got the danios a couple of days ago and both seemed fine, apart from chasing each other a little aggressively, until today.
The larger one which I think is a female is now sitting about 1cm below the surface with her tail lower than a head and looks like she is gasping for air. She also ignores iny food put in the tank. The other danio appears fine and is swimming around happily.
I did one 25% water change yesterday.
I have tested for ammonia using the nutrafin mini master test kit and it came back as completely negative.
The tank is at 25 degrees c or 75f but the ill fish seems to be sitting by the heater.

Should I do a water change or is it a swim bladder or infection problem?
Thanks for any help in advance

 

[snazy]

Test again and make sure to follow the instructions on the test properly. In a non-cycled tank they are more than likely being poisoned by ammonia or nitrIte or both.
In a fish-in cycle 80-90 % water changes are needed at once, not 25% as 25% water taken out removes only 25% of toxic ammonia and nitrIte and renders your water change useless.

 

[Puddles92]

Test again and make sure to follow the instructions on the test properly. In a non-cycled tank they are more than likely being poisoned by ammonia or nitrIte or both.
In a fish-in cycle 80-90 % water changes are needed at once, not 25% as 25% water taken out removes only 25% of toxic ammonia and nitrIte and renders your water change useless.

So I tested again and got the same results of 0 for ammonia, nitrates and nitrites.I did a 50% change and will see how that goes.The sick fish is now hiding at the bottom of the tank apart from when it gets chased by the other one. It does seem to be able to swim normally and as fast as the other one.

 

[Puddles92]

Just before the water change she was sitting at the bottom of the tank hiding in an ornament, now she is as she was earlier, swimming at an angle of about 45 degrees at the top of the tank and occasionally sinking. Could it be I over fed them yesterday as that fish ate most of the food and now she is just constipated or is it more likely toxins in the water even though the tests come back negative?

 

[snazy]

Is the filter flow moving the surface of the water?

 

[Puddles92]

Yup. There are lots of air bubbles near the filter as it is a fluval chi the water is pumped up through the filter above the water and falls back in as a little water fall. It does push the bubbles down as you can see tiny air bubbles all around the tank. Is swimming slightly flatter now although still near the top.

 

[snazy]

Just keep testing the water as you should have ammonia reading pretty soon in the next couple of days. If it still reads 0 I would worry that there's a problem with the test.

 

[Puddles92]

Ok thanks. Do you know how accurate the nutrafin mini master kit is? Or know of anyone who has used it.

 

[Puddles92]

I just did another 50% water change as although the reading was 0 initially I came back to it an hour later and it had gone up to about 0.25 ppm for the ammonia. I don't know if that means its my actual reading or that's what happens when you leave the test.Anyway the sick fish seems to be swimming more level and is not struggling as much to stay afloat. It's still hiding away but not as much and doing a bit more swimming so I think it's on the mend whether it was a swim bladder problem or a toxin level problem

 

[Puddles92]

So she was looking better before the second water change but now she is back to sitting on the bottom of the tank struggling and doing a lot of flapping. What should I do?

 

[CezzaXV]

Are you following the instructions on the test?

I know with the API kit you have to leave it for five minutes before reading the result. Dont know about the Nutrafin one though.

 

[Jam Jam]

Are you treating the tap water with conditioner before adding to the tank?

 

[Puddles92]

So the fish seem to have settled down know both seem happy and healthy but I can't get the tank to cycle.I have 2 zebra danios in a 25l tank and they have been in there for a week.I did quite a few water changes when they were looking ill but it has been 3days since the last change and there are still no readings for ammonia, nitrite or nitrate.I did a 50% change today to be safe but why haven't I had an ammonia spike, is this normal?Is there anything I should be doing?

 

[Jam Jam]

I have no idea as I am a biginner,but maye try changing the water more regular a big water change to get nitite to zero.Then a 25% change everyday after tests ?

I am having a mare with my own tank with high Nitrites,found a dead fish in filter that went missing a while ago.DOH
I had no idea they could get in there to be honest