2 Fish Dead - Possibly More To Come Need Help!

[Ilikefishes]

Hi all - I have got a 180lt community tank. Been running fine for 6 months +. I wake up this morning with 1 dead polka dot loach and 1 pakistani. All other fish are at top of tank gasping. Any ideas what that means? Remaining fish - 1 Gourami, e3 Rainbow, 10 neon tetra, 2 blue ram, 1 pakistani, 1 polka, 1 zebra loack, 1 UPD catfish. Will post water stats soon!

 

[Ilikefishes]

Ammonia 1 Nitrate 0.25 nitrate 10

 

[Mr Bliss]

Is the temperature in the tank normal? Sounds like what happens when heaters malfunction and decide to leave themselves on.

Is the filter running normally? Other likely causes include acute ammonia or nitrite poisoning, acidosis from a pH crash, oxygen depletion due to something decomposing in the tank. I'd start with a 50% or 75% water change right away, and make sure the flow from the filter creates as much surface turbulence as possible.

Have you noticed any symptoms in any of the fish before this?

 

[Mr Bliss]

Ah just saw the water stats. Seems like ammonia poisoning then. Change 50% of the water ASAP, change another 50% in the evening. Need to figure out what's causing the ammonia to spike, as you shouldn't have a detectable level in a mature tank, but the important thing right now is to get the ammonia level down.

 

[Haych]

also, you say theyre gasping, is there enough movement on the water surface to keep the water oxygenated?

 

[LauraFrog]

Gasping is classic ammonia poisoning, ammonia interferes with oxygen metabolism so the fish are at the top where there is more oxygen, trying to breathe. Immediate 60% (min) water change, open your filter and check that nothing is obstructing the flow but don't clean it out unless it's clogged up. Drop the temperature by two or three degrees C as this reduces free ammonia and slows fish metabolism slightly. Add ammo-lock or stress zyme if you have it.

Are all the other fish in the tank? If a fish 'goes missing' ie dies and gets wedged behind or under an object, the rotting carcass can cause an ammonia spike.

The fact that there is a nitrite reading is a good sign as it means that your filter is already beginning to process the spike, and this means that it's unlikely that something has killed your filter.

 

[iffles]

Have you found the bodies and whats the temp and pH? As mentioned above ^ lower the temp and add ammo lock or nutrafin cycle to absorb the ammonia and nitrite. did you add any new fish recently or add anything? did you do anything differently to possibly trigger the spike?

 

[Ilikefishes]

After removing dead fish and changing water the rest of the fish have stopped gasping and seem ok. Will do another change soon and test water again later. Thanks for your help everyone.

I think I know what caused the problem though - the tank is a Juwel Vision with a built in filter. I installed a Fluval 304 external filter months ago, which has been running ok. I turned off the inbuilt filter the other day as I planned to remove it and leave the filtration up to the Fluval external. Do you think this is what caused the problem?

 

[Haych]

shouldnt be as the external has been running for long enough.

did you disturb the substrate when you removed the filter?

i had this same issue, a massive spike when i moved my tank and disturbed the sand, creating an ammonia spike, which then leads to nitrite and nitrate

 

[Ilikefishes]

Hi yeah I did disturb all the plants and sand yesterday when doing a water change. There was a fair amount some old food and rotting leaves so I guess that might of caused the ammonia. Hopefully everything is back to normal now though.

 

[Haych]

thats exactly what i did!

i had an ammonia and nitrite spike, and now ammonia is going down and nitrates up cause the filter is dealing with the added ammonia

 

[Mr Bliss]

Glad to hear the fish are doing better.