Ammonia Spike Kills 1 fish

[fisshy]

Background
I have a 30 gallon freshwater tank with a Whisper 90 filter fake plants 1.5" aquarium gravel and 4 (now 3) mature african cyclids and a spotted catfish. The tank is 1.5 yrs old and we do a 20% water change every 1-2 weeks. I use amquel, Novaaqua and aquarium salt in recommended amounts to neutralize Clorimines in the water and replace electrolytes. I also wash out the bio filter weekly in declorinized water.

Since I have established the tank I have never had a cycle problem. My Ammonia and Nitrite Levels have always been 0. Infact they were they were so stable I stopped checking them (yes I realize I would have saved the dead fish if I had been checking.) Bottom line we noticed a slow down in food consumption over the last couple of days and came back today to find one fish dead on the bottom, one having swim bladder problems (it kept floating head up to the top then swimming back down). I immediately took out the test kit and found Ammonia off the scale and Nitrite slightly elevated.

I transferred the sick fish to a hospital tank and did a 50% water change and added Amquel to bindup more of the ammonia. The amquel seems to be interfering with the ammonia test so I don't know how the tank is doing now.

The dead fish showed bleeding in the scales.
The sick fish is showing ratty fins. But seems to be swimming better after an hour in fresh water.


Question:
What could have killed my nitro bacteria?

What do I need to do to re-establish the Cycle with out further death.

What do I need to do to help the remaining fish recover.

Thanks!!

 

[ferret]

You definately have an odd problem. I can't offer an immediate solution, but at one point I had 12 adolescent to mature african cichlids with a common pleco in a 29 gallon and it never spiked once. I have a Penguin 330 BioWheel on the tank.

Have you change your filter media or anything recently? I'm also not sure if washing out the bio filter is a good idea. And to beat everyone to the punch, the salt/electrolyte thing seems to have been disproven, and will interfere with Zeolyte based ammonia absorbers.

 

[grimlock3000]

"I also wash out the bio filter weekly in declorinized water."

I am not certain how the Whipser 90 filter is setup, so some of this may not apply to you... You want the bio filter to get all nasty with bacteria, because those are what consume the ammonia and nitrites in the water. If you kept washing that out all the time, you kept throwing away all the good bacteria as well. There is a lot of bacteria that live in the rocks and other surfaces of the tank, so that is likely was was keeping the the tank cycled.

When you clean the mechanical/chemical filter pads (foam, sponge/carbon) you need to be careful with the bacteria as well. Clean out sponges and pads in tank water, and never replace all the filter media at one time. Usually, you will rinse half the media in tank water one week/month, then the other half next time.

Why did this happen in the first place? It could be any number of reasons. It is unlikely that something got into your tank and just killed off all the bacteria, it is more likely that the bacteria could not keep up with some of the events in the tank, or you removed the bacteria by changing or washing too much filter media.

To get everything back in line, do frequent testing and water changes to get the ammonia lower, and leave the bio filter alone so it can re-establish itself.

 

[Allivymar]

Its possible your tank suffered from whats known as "old tank syndrome"; how does the tank pH compare to the tap water's?

There's an article here that explains it better then I: http://www.tomgriffin.com/aquasource/oldtanksyndrome.shtml I'm not sure if its 100% what happened but its possible its part of the problem.

 

[sweetsuvvyb]

I use amquel

When do you use Amquel? This jumped out at me immediately...doesn't the amquel convert the ammonia to ammonium (or to another compound that isn't toxic to fish)? If you are using this regularly...then you might not have had a strong bacteria colony to begin with!

I could be wrong...but it is something to consider...

 

[jsoong]

It says on the Amquel bottle that it will not interfer with the cycle (if you can trust it!)

I believe that Amquel binds reversibly to NH3. So as free NH3 is used up, more will be released & keep feeding the cycle.

This actually is one problem I have with Amquel & othe NH3 binder - under proper condition, the NH3 can leach back out. I've also investigated Prime by Seachem (an Amquel clone) and they told me that Prime will disappear in 24 HRs, so I was left wondering what would happer if I use that to bind up a bunch of NH3, and the stuff disappears - an NH3 spike?

 

[sweetsuvvyb]

Well, in any tank, you already have an equillibrium that exists between NH3 and NH4 (dependant on pH, and temperature). So any additive that attempts to alter that equillibrium (ie...by removing NH3), is probably going to have repercussions...which is why I generally try to stay away.

 

[fisshy]

:| Thanks to Allivymar. I believe that Old Tank Syndrome is the root cause. My tap water is very hard GH of 16 and a KH of 6-8 with a PH of 8.2

After reading the article I checked the tank was at ph of 6.6 with a KH of 2.

I have done two 30 percent water changes and a small amount of PH up to gradually get the ph over 7, but the PH keeps diving down to 6.8. I measured KH and it was only up to 5 so I added 1 tsp of Sodium Hydrogen Carbonate (baking soda) to up the buffer and recieved a KH reading of 7 and a ph of 7.2.

I had moved the one very sick cichlid (he had swim bladder problems and bleading on the scales) to the hospital tank and have been treating with Miracyn and miracyn two. This fish is still not eating, is sluggesh and has bad color, but the bleading is gone as is the swim bladder issue. We will watch him day to day.

The other fish are not eating much, but are eating. They are acting a bit sluggish, but are swimming normally. So far...


I had initially bound up the ammonia with amquel, which I have learned from the forum converts it from NH3 to NH4, both show up with a nesler reagent test. Which unfortunately was the only test I have (as does the local pet store). Trend wize I can see that NH3/NH4 is dropping. And Nitrite level is starting to rise showing that the tank is starting to cycle. I am not sure what you guys think about the bacteria additives (cycle etc.) But I added some with the logic that It would beef up the colony and cycle faster.

Any additional suggestions to get the tank back into shape with out killing the fish. Also how long do you think it will take to get the tank back to statis?

thanks
fisshy