Lost 95% of my fish in three days

[satch]

With that said... I am heartbroken right now. I don't want to give up so I'm turning to this site for advice.

Here is my situation...

I've got a 29 gallon freshwater tank that has been up and running for about 5 years now with gravel, fake Plants, and other decorations you can buy at fish stores.

An oversized filter that hangs on the back of the tank. I rarely changed the fliter. Occasionally I would clean the filter when it got really caked up. I cleaned with soap and water not knowing this was bad at the time.

8 of the original fish puchased back in 2003 lasted for many years. I'd lose one every so often. I purchased an occasional batch of fish throughout these five years and most would last a few months or more. But they all eventually die.

I've been a very lazy aquarist. I would do 40% water changes (using declorantor stuff) every month and half to two months Usually when evaporation took over and the water drop from the filter to the tank started to get annoying with large water spashes. Sometime's I'd be even so lazy as to just top off the tank with new water. But most of the time I'd use the gravel filter sucking up the yuckies from the bottom of the tank. I figure my lack of manteniance is why I've lost fish throughout the years. I'm still curious how the original batch of fish lasted the longest. They were Buenos Aires Tetras, and Red Eye Tetras: A total of 8. I had all of these 8 most of the years. New fish would come and go, but these fish always lived.

EVERYtIME I test the water it ALWAYS shows nitrates and amonia as safe levels. Water is somewhat hard, and the water in my neighboorhood is high alkanity - its off the charts. I've considered buying an RO unit, but not sure yet.

About a month or so ago we lost power at our house for about 24 hours or so. When the power came back on the filter no longer worked. It was all caked up with gunk from my lack of maitenance, so I just tossed it and bought a new one. Soon after this new filter was setup, I also bought more fish and a new attitude to do a better job at fish maitenance. I bought 3 new fish every 5 days or so until I had about 15 fish in my tank.

Here are the fish that were left in my tank after power outtage:

Fish Quantity Purchase Date
Buenos Aires Tetra 1 1/1/2003
Red Eye Tetra 1 1/1/2003
Neon Tetra 1 6/1/2008
Goldfish 1 8/1/2008

After power outtage I bought these fish:

Zebra Danio 3 9/1/2008
Swordtail Female 2 9/5/2008
Swordtail Male 1 9/5/2008
Plecostomus 2 9/10/2008
Neo Tetra 3 9/15/2008


I started to do weekly 40% water changes as is recommended. I also let the water sit for a week as you may have read about in this post: http://www.aquariumadvice.com/forums/f12/water-change-sit-for-a-week-cloudy-after-change-107040.html. I am wondering if that could have been the problem with my fish death so I'm no longer going to do this method anymore.

A few days ago I noticed some of this fish had what appeared to be Ich. So I did a massive 90% water change and put some salt in the tank. I continued to lose fish and now I've only got three Danio's left. One of them looks like he's about ready to kick the bucket. I'm devistated. Is this a case of new tank syndrom because of the new filter? I'm temped to just trash the tank and start over fresh with new fake plants, new gravel, and then follow the cycle procedure for new tanks. Is this what you all would do?

 

[neilanh]

Do you have a good, quality test kit, and were you using it?

15 new fish that fast I suspect caused an ammonia spike, and also it sounds like the new fish introduced ich into your system. These 2 things together are probably what caused your issues.

Whenever you have a stable tank, there's enough bacteria in there to support the bioload that you have, no more than that, so whenever you add new fish, you need to give time for the tank to restabilize before adding more.

You didn't say how long after the power outage did you start buying the new fish. If it was more than a few days, then all of the bacteria that you did have probably died off from lack of a food source, so you were starting nearly at square one.

Like I said, I believe that the biggest issue that caused the problem is the extreme change in bioload in a 2 week period, it was just too much and caused what's probably a pretty significant ammonia spike.

 

[Acer]

that and maybe if was was sitting without any kind of agitation it might of "gone bad".. if your tank has ich i recomend turning the heat up and everyother day gravel vac-water change. make sure that with high heat you have surface agitation or oxygen levels will drop because of heat. and dont go past 90 degrees... make sure you turn off your heater for at least half an hour before starting to do anykind of pwc.

 

[jsoong]

About a month or so ago we lost power at our house for about 24 hours or so. When the power came back on the filter no longer worked. It was all caked up with gunk from my lack of maitenance, so I just tossed it and bought a new one.

Tossing the filter was a bad idea .... The nitrifying bacteria live in the filter pad and it would have been better if you seeded the new filter with the filter pad from the old .....

As it was, the filter change & adding all the new fish prob. combined to give you an ammonia spike, stressing & killing the fish.

Since you are now down to 2-3 Danios, you can reestablish the cycle using those. You need to get rid of ich with adequate salt level (0.3%) or with heat. And it will take at least 2 weeks of treatment. Meanwhile, make sure you test the water daily for ammonia & nitrites. Do water changes as needed to keep the levels low. Once your tank is cycled (0 ammonia & nitrites & presence of NEW nitrates), you can reintroduce new fish, but only 2-3 every few weeks.

Your other option is to do a complete tank tear down & sterilization, return then Danios, and re-establish the cycle using the fishless method.

Either way, you are looking at weeks before you get your tank up and runnign again. Patience is key in this hobby!!

 

[MichaelsLilGray]

...a few of the fish he mentioned.. dont do well to salt treatment.. swordfish plecos and loaches, dont really do well at all with salt. With a tank that was established for 5 years.. he should have had enough nutrifying bacteria left in the gravel and on the plants to have "seeded" the tank for such a small bioload... The fish he put in the tank are some of the smallest (excluding the pleco's) you can get. I wouldnt be so haisty to say the 15 fish killed themselves with an ammonia spike. thats 15 inches of fish in 29 gallons of water... and a small 15 inches at that.