Black Neons Swimming Strange

[apollo0681]

1. Water parameters. (ammonia, nitrate, nitrite, PH, temp', Hardness etc)
everything thing is normal except the nirate is high. This happened around a month ago. i seeked advice on here and have been getting it down by doing water changes and trying to build up the live plants in the tank and took a pleco back to the pet store
 

2. A full description of the fishes symptoms.
The fish are swimming with there noses in the air as seen in the picture (not great i know) of the 10 black neons 5 are doing it. Only three were yesterday. I first suspected they might have been over fed as girlfriend had been feeding them over the weekend as i was away. they havent been fed for 24hours now.
The bright line on the tetra has dulled slightly in the effected fish. The black line also appears to be greying aswell.

3. How often you do water changes and how much.
have been doing 25% water changes weekly

4. Any chemicals and treatments you add to the water.
None
5. What tank mates are in the tank.
9 neon tetra, 9 harlequins 4 cory, 1pleco and a catfish. no other fish are acting like this. the neons are fine which is why i havent lept to the NTD solution. The neons were bought around a year ago the harlequins and black tetra were bought around 3 months ago the rest of the fish are 5years+
6. Tank size.
200 litres
7. Finally Have you recently added any new fish?
last fish were added about 2 months ago.
Since then a pleco has been removed.
 
 
 
 
 

 

[phoenixgsd]

can you tell us what the normal readings are exactly? also i notice you say  
.....Any chemicals and treatments you add to the water. None.....does that mean you dont dechlorinate your water?
have you done anything to the filter, cleaning ect

 

[apollo0681]

Well i use a 6in1 tester kit which shows all levels are on the safe part of the scale except nitrates.
I thought chemicals meant any treatments i might have made. which is why i said none. I do dechlorinate the new water.
 
About 2 weeks ago i added some new sand to the tank. i washed the sand throughly first. Infact it only went slightly cloudy for an hour or so before going clear again. The pleco has been kicking up alot of the sand  diging himself various places to hide in. I usually clean half the filter at a time as was told you shouldnt do it all at once and the last time i did this was about 3 weeks ago.

 

[apollo0681]

anyone have any ideas?

 

[apollo0681]

been about 2days since i first asked for help. Situation hasnt changed. the same few fish are still swimming nose up. no other fish have started to show the same problems. If i go near the glass of the tank the fish get spooked and begin swimming normally but within 30seconds are back doing the same thing as before

 

[daveg6529]

I have 11 penguins with other tetra's in a my 260L tank. My penguins all do the same. I have found that in a particular part of my tank they swim nose up at a 45 degree angle without any ill effects. I have come to the conclusion that it is due to the water flow (downward).
If any one has any answers as to another reason I would be interested.

 

[JonesyJ666]

pretty sure after reading about and going down to mu local fish store, that this is normal, all be it very strange