Possible Nitrite Poisoning - Fish Not Recovering

[cybergibbons]

Got a call last night from my girlfriend - she thought the fish had died or were dying. We had a betta and 4 cory catfish - one of the catfish appeared to have fungus last week and has now died. I do not know if the death was natural or just that he was weak and the shock of this finished him off.

Tank size:38l, started cycle about 11 months back, had stable readings for last 6 months.
pH:7.8 - this is the same as always
ammonia:0ppm, has stayed at 0ppm
nitrite:Currently 0ppm, but did test at 5ppm+,2ppm,1ppm,0.5ppm,0.25ppm
nitrate:30ppm
kH:n/a
gH:n/a
tank temp:25C

Fish Symptoms (include full description including lesion, color, location, fish behavior):
Virtually no movement over last 12hours. Gill movement has been fast/shallow and now has slowed and seems deeper. Cory are sat in mid tank on plants, betta hiding at back. Still respond to stimulus. Betta appears slightly swollen and has lost some colour at front of body, no pineconing though. Cannot see red/brown gills on any of them.

Volume and Frequency of water changes:
Usually 40% every 2 weeks. Missed a change, so about 2.5weeks since last change.

Chemical Additives or Media in your tank:
Added Interpet Finrot and Fungus at half dose to treat fungus on cory (which is now dead)
Liquid carbon and ferts added daily - this has been done for last 5 months.

Tank inhabitants: Betta + 3 cory catfish

Recent additions to your tank (living or decoration):
None

Actions taken:
Increased aeration by moving spraybar.
Tested water, high nitrates.
Added 2ml of Seachem Prime (2x normal full tank dose)
12l water change
12l water change
<waited a few hours, nitrite lower at 0.5ppm>
12l water change
Added 1ml of Seachem Prime
<waited overnight>
Nitrite testing at 0ppm, fish symptoms unchanged.

So I guess the question is - is this nitrite poisoning? How long will they take to recover? What further actions should I take? My plan was to continue doing water changes as the Seachem Prime will wear off soon.

Thanks for any help and advice.

 

[KittyKat]

nitrite:Currently 0ppm, but did test at 5ppm+,2ppm,1ppm,0.5ppm,0.25ppm

Time period? When did you read 0ppm? When did you read 5ppm after that? etc

Fish Symptoms (include full description including lesion, color, location, fish behavior):
Virtually no movement over last 12hours. Gill movement has been fast/shallow and now has slowed and seems deeper. Cory are sat in mid tank on plants, betta hiding at back. Still respond to stimulus. Betta appears slightly swollen and has lost some colour at front of body, no pineconing though. Cannot see red/brown gills on any of them.

I guess you do not have a second fish tank?

Volume and Frequency of water changes:
Usually 40% every 2 weeks. Missed a change, so about 2.5weeks since last change.

It is generally better to do smaller, more frequent water changes. Do you dechlorinate your tap water?

Chemical Additives or Media in your tank:
Added Interpet Finrot and Fungus at half dose to treat fungus on cory (which is now dead)
Liquid carbon and ferts added daily - this has been done for last 5 months.

Do you have a general "calming" product? Anything which can promote slime coat growth and with aloe? Usually they are a gimmick, but this once they might actually do some good.

Actions taken:
Increased aeration by moving spraybar.
Tested water, high nitrates.
Added 2ml of Seachem Prime (2x normal full tank dose)
12l water change
12l water change
<waited a few hours, nitrite lower at 0.5ppm>
12l water change
Added 1ml of Seachem Prime
<waited overnight>
Nitrite testing at 0ppm, fish symptoms unchanged.

Do you add dechlorinator after putting water in the fish tank, or before?

So I guess the question is - is this nitrite poisoning? How long will they take to recover? What further actions should I take? My plan was to continue doing water changes as the Seachem Prime will wear off soon.

Probably. They may never recover from 5ppm of nitrite, it is quite toxic.

 

[cybergibbons]

nitrite:Currently 0ppm, but did test at 5ppm+,2ppm,1ppm,0.5ppm,0.25ppm

Time period? When did you read 0ppm? When did you read 5ppm after that? etc

1930 - 5ppm+
2000 - 2ppm
2030 - 1ppm
2100 - 0.5pmm
2130 - 1ppm
2200 - 0.5ppm
2300 - 0.25ppm
0000 - 0.5ppm
0545 - 0ppm

Fish Symptoms (include full description including lesion, color, location, fish behavior):
Virtually no movement over last 12hours. Gill movement has been fast/shallow and now has slowed and seems deeper. Cory are sat in mid tank on plants, betta hiding at back. Still respond to stimulus. Betta appears slightly swollen and has lost some colour at front of body, no pineconing though. Cannot see red/brown gills on any of them.

I guess you do not have a second fish tank?

No, just the one.

Volume and Frequency of water changes:
Usually 40% every 2 weeks. Missed a change, so about 2.5weeks since last change.

It is generally better to do smaller, more frequent water changes. Do you dechlorinate your tap water?

Yes, I use Prime on the water before adding it to the tank.

Chemical Additives or Media in your tank:
Added Interpet Finrot and Fungus at half dose to treat fungus on cory (which is now dead)
Liquid carbon and ferts added daily - this has been done for last 5 months.

Do you have a general "calming" product? Anything which can promote slime coat growth and with aloe? Usually they are a gimmick, but this once they might actually do some good.

I have Stress Coat, but I'd be concerned about adding this in addition to Prime.

Actions taken:
Increased aeration by moving spraybar.
Tested water, high nitrates.
Added 2ml of Seachem Prime (2x normal full tank dose)
12l water change
12l water change
<waited a few hours, nitrite lower at 0.5ppm>
12l water change
Added 1ml of Seachem Prime
<waited overnight>
Nitrite testing at 0ppm, fish symptoms unchanged.

Do you add dechlorinator after putting water in the fish tank, or before?

Before.

So I guess the question is - is this nitrite poisoning? How long will they take to recover? What further actions should I take? My plan was to continue doing water changes as the Seachem Prime will wear off soon.

Probably. They may never recover from 5ppm of nitrite, it is quite toxic.

I'll see what happens then. Thanks for the help.

 

[KittyKat]

nitrite:Currently 0ppm, but did test at 5ppm+,2ppm,1ppm,0.5ppm,0.25ppm

Time period? When did you read 0ppm? When did you read 5ppm after that? etc

2100 - 0.5pmm
2130 - 1ppm
[...]
2300 - 0.25ppm
0000 - 0.5ppm

Shows that it is coming from something in the tank. I assume you removed the dead fish quickly?

Chemical Additives or Media in your tank:
Added Interpet Finrot and Fungus at half dose to treat fungus on cory (which is now dead)
Liquid carbon and ferts added daily - this has been done for last 5 months.

Do you have a general "calming" product? Anything which can promote slime coat growth and with aloe? Usually they are a gimmick, but this once they might actually do some good.

I have Stress Coat, but I'd be concerned about adding this in addition to Prime.

Won't hurt to try: next water change, use Stress Coat and dose with enough for the whole tank.. by now, there should not be any Prime left in the system..

 

[cybergibbons]

The fish was alive at 0600 and was dead by the 1800 and then removed straight away. So not a huge length of time.

Will probably do another change this evening.

Thanks.

 

[cybergibbons]

The fish was alive at 0600 and was dead by the 1800 and then removed straight away. So not a huge length of time.

Will probably do another change this evening.

Thanks.

Ammonia and nitrites staying at 0ppm now.

The three cory have been moving about slightly, though very very little. The betta has returned to the top of the tank near the heater, and has responded to movement a few times but seems very swollen. Hard to tell if there is any pine coning as he is quite hidden.

 

[KittyKat]

Not much you can do if there is no disease.. if you have access to an oak tree in an unpolluted area, you could try adding a couple of oak leaves to the tank, they will have a kind of "calming" effect on the fish. They will stain your water.