I've Got The Neon Blues...

[pixelpefekt]

Hi. Had my tank up and running for around 3 months now and have had no problems other than one guppy loss - for reasons unknown (water tests were fine).

On Saturday I added new fish:

8 small neons
2 guppys
2 amano shrimp

One of the neons died in the first couple of hours, one that night and another the next morning. I've noticed this morning that another is looking pretty ill (not swimming well - almost vertically, which was the first signs of the previous fish)

I've tested the water which shows Amonia 0, Nitrite 0 but my PH has dropped from 7.2 to 6.8 and the Nitrates are now showing 0 too. Nitrates in my tank have never really shown high readings but I've never seen them zero out.

Can any one offer any advice? Why might these fish be dying and why might my PH drop and Nitrate fall?

p.s - current tank details before addition of new fish:
60l tank
6 zebra danios
1 guppy

 

[acula]

I had this prob too and it turned out to be this

Is the water being oxygenated enough (filter causing bubbles at the surface)

 

[Miss Wiggle]

oxygen content can affect the pH of the water, so it could be that you're filter just needs a clean out and the flowrates dropped meaning your oxygen content has dropped off too. did you add anything else with the neons, any new plants or decor?

neon's are notoriously weak nowadays, it's not recommended to add them to tanks under 6 months old, even though your main levels (ammonia, nitrite, nitrate) may be reasonably steady there are a zillion other chemical changes going on in the water when the tanks new which just take time to settle down, weak fish often don't acclimitise well in these unstable conditions, I suspect that's what's done for your neons.

the nitrate is probably a duff test, nitrate test kits are notoriously dodgy, have you done a re-test

 

[backtotropical]

I agree with Miss Wiggle. Neons need a mature tank and nitrate tests are notoriously dodgy.

I added 40 neons to a newly cycled tank and they died 1 by 1 for no apparent reason. I ended up with 18 in the end.

Cheers

BTT

 

[pixelpefekt]

I didn't add any decor plants.

The oxygen thing could be a possibility.... I have a Fluval 2+ filter which spits the water out near the surface and creates bubbles. Last week I reduced the bubble out put from the venturi thingy because I had added an air stone and bubbling treasure chest (for the kids). However, at nights I've been turning off the air stone. I wonder if this is leading to the deaths

I'll turn it up full as soon as I get home. Wonder how long till I will know.

Is there a test for how much oxygen is in the water?

 

[waterdrop]

I think you are just confirming that its not idle chat that neons are sensitive fish! (they just wanna be back in that particular curve in that particular amazon stream..)

I believe there are indeed oxygen test kits but I don't know how accurate or reliable they are, have never used one myself.

~~waterdrop~~

 

[LosC519]

If it's lack of oxygen you would find your Neons swimming right at the surface and gasping for air. How did you acclimate them? You could have a bad batch of Neons

 

[pixelpefekt]

I think you are just confirming that its not idle chat that neons are sensitive fish! (they just wanna be back in that particular curve in that particular amazon stream..)...

I've been putting off buying them from the start. I knew they liked a mature tank but a mixture of LFS owner repeatedly telling me they'll be fine and that they are hardy enough to be first fish mixed with good test results from my tank got me lulled into a false sense of security I guess.

If it's lack of oxygen you would find your Neons swimming right at the surface and gasping for air. How did you acclimate them? You could have a bad batch of Neons

The one I watched this morning was vertical at the surface. I guess this fits.

Acclimatisation: 20 mins of bag floating in tank. Some tank water added to bag then left for 10 mins. Then into the tank.

 

[pixelpefekt]

Meant to add. Yes, I did re-test the nitrate level this morning and it still showed 0. Could this mean the bacteria have dies some how? Should I expect an Amonia spike??

(I used the API freshwater master test kit)

 

[rabbut]

Of flow through the filter has dropped, it could have gone anairobic, where there are bacteria converting ammonia into nitrogen gass and oxygen, and also converting nitrates back to ammonia for conversion to nitrogen and oxygen. This happens very rarely, but it can happen none the less. Try cleaning out the filter and doing a large-ish waterchange between 30 and 40%. After cleaning, get the venturi turned up again.
Neons are flimzy, so this may just be the issue. Try Cardinal tetras next time, they are similar to cardinals and generaly hardier

All the best
Rabbut

 

[pixelpefekt]

Good news
Did a full set of tests again last night and the Nitrates were back. Maybe is was dodgy tests?

Nirtates between 5 & 10
Amonia, Nitrites were at 0
PH still slightly down at 6.8 (normal for me is 7.2)

Bad news
Lost more Neons yesterday. Now there are only 3 from 8. They at least seem more healthy. They are more active and are eating fine. They are also out mingling with the other fish rather than hiding away.

A friend mentioned to me that I shouldn't be concerned too much as they were cheap to buy but I don't see this as a money issue. I hate to see any of the fish die regardless of cost. Fingers crossed for the last few!

 

[Miss Wiggle]

i agree with you about dodgy nitrate tests, particularly if the nitrates are only around 5/10ppm then a dodgy reading could easily read 0. it's best to think of nitrate tests as an indicative reading rather than anythin too factual.

i really think this is just a case of weak fish in an immature tank.

and you're right as well, the fish may not have much monetary value but that does not mean that their lives hold no value.