Fish gasping at surface.

[joltz]

I have noticed recently a few of my fish seem to be sitting at the top of the tank gasping for air.

My swordtail died, a couple of days ago, today i noticed my blackghost knifefish doing it also, and it seemed very weak looking, i kept a eye on it for a few hours and it seemed exhausted and wanted to rest, it seemed to do fine but then it just died.
When I took it out of the tank, it looked like parts of it skin were coming off around it body and some of its fin bitten off.

And just now ive noticed a black tetra doing the same, however no 2 fish seem to do it at the same time. The black tetra however doesnt seem to have any physical markings on it like its been in a fight, swordtail never did either.

I have plenty of plants in my tank plus one of those air bubble maker things that sit under the gravel.

I tested my PH, it was fine.
I tested my ammonia and it was absolutely not present, totally 0. I tested it twice to make sure.

What else should i test?
I bought some ammonia neutraliser and added just abit to my tank to play it safe, I also bought this stress zyme stuff to help add bacteria to the tank, because i recently changed the whole thing around and added ALL new water.

What else can i do?

 

[Cian McLiam]

My guess would be nitrite and/or chlorine from the new water. If the new water was not thoroughly de-chlorinated and aerated, its quite possible that all tthe benifical bacteria in the filter were wiped out.

I would never recommend doing a complete water change unless it was a case of extereme pollution, 30% would be the maximum I would do daily to resolve any water quality problems.

This isnt much help to you now, but something to keep in mind.

First off, you need to test for nitrite, if it is high, you will need to do 20% partial water changes everyday until it is gone, using water that is thoroughly de-chlorinated and if possible, let sit overnight with an airstone. I findthat ading some 'blackwater extract' that you can get in good shops, helps take some of the rawness out of tap water. Only a few drops should do the trick.
There could perhaps have been a pH difference between the water you removed and the new water. When you say it is fine, what reading is it? and what is the reading from the tap?

If a tank is left without water changes for some time, the pH will naturally drop slowly as waste and CO2 levels rise. It may have been very different from the raw water you added.

Start with the water changes and let us know what results you get from the pH and nitrite tests.


Ken

 

[akhtar]

good luck, i had the smae problem ,the fish kept breathing from the top! i think some of the bacteria died off, so it recovered after a few days...

good luck

 

[Bol]

Ken is most likely right, but could (air stone) + (lots of plants) lead to a lack of oxygen in the water?

 

[mrnewbie]

Ken is most likely right, but could (air stone) + (lots of plants) lead to a lack of oxygen in the water?

exactly what i was going to say

 

[White Whale]

It might be the PH.

 

[thecichlidaddict]

It really sounds like nitrite poisoning to me.

 

[Cian McLiam]

Cation is right, the air stream will increase gaseous exchange at the surface, trading co2 for oxygen, likewise, the plants will photosynthesise during the day, releasing oxygen and will do the reverse during the night, using oxygen to feed in dark conditions. I dont think a lack of oxygen is the likely cause, but it is more likley that something is preventing the gills from using the oxygen ie. nitrite poisoning/parasites/pH burns.

Ken

 

[tdins_2]

i think you should check ur ph and it sounds like a nitrate problem

 

[joltz]

My black tetra now seems fine, however waking up this morning I found my guppy dead.

PH is spot on, and ammonia seems to be non existant after doing another 2 tests today.
I dont have anything to test my Nitrate, going to buy a kit today.

Also I noticed that this seems to be happening after i turn my light back on after i switch it off for about 6-8 hours a day, so im going to try it without turning the light off for a week now.