# Fish are dying



## yiorgos (Apr 12, 2009)

Hello, I have a 90 ltr. tank since 2007. Everything was fine until last summer I had about 15 fishes in there neons, black skirt tetras, and a couple of other species. They were mostly small fish. Anyway, I left for an extended vacation last summer and when I came back only three were left. I did not find any remains of any dead fish in the tank (???). Since then, I have only 1 black skirt tetra left (from 2007). Every fish that I buy dies within a matter of weeks or days. I had completely emptied the tank and washed everything (except the gravel). The water condition is fine. I use biological filtering. I don't know what to do. Should I change or wash the gravel for some reason. There are no live plants. I got my first tank when I was 12 back in 1980 so I'm not new at this but I'm hitting a wall here.


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## Manafel (Sep 4, 2011)

Hello,
I know you said you water quality is fine, but what are your actual water parameters? how old were the fish you had previously? any new additions lately?


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## Arthur7 (Feb 22, 2013)

It is likely that arose in the soil due to oxygen-consuming bacteria.
You have no living plants. This means that the few oxygen from the water change is rapidly consumed and the fish suffocate.
Should contain I think that the aquarium live plants illuminated, and fish in a favorable ratio. Then forms, with time, a healthy soil flora.


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## Manafel (Sep 4, 2011)

If they have any surface agitation at all, it should provide enough oxygen in the water to sustain a healthy environment


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## coralbandit (Jul 29, 2012)

Fish from 2007 would be 7 years old.I find fish to be the opposite of dogs.Where small dogs live longer than large dogs,small fish live/have shorter lives than large fish.Tetras and such lasting 7 years is pretty good!It is always a bummer to lose fish,but if you don't see any signs of disease or other issue(water quality) I would chalk the deaths up to old age.
As for why new fish can't survive,how do acclimate them to your tank.I have seen many times where fish in the tank will be fine but new additions drop like flies.It is either water quality or acclimation IMO.Is this the tank you want to adjust pH in?


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## bolram (May 17, 2011)

If your parameters are unchanging and at the levels you have always known then try asking the LFS you use to supply their own water parameters of the fish you are purchasing. It could be they have very different parameters to your own so you would need to acclimate the fish over a more extended period than average just to be safe


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## Buerkletucson (Apr 8, 2014)

May sound drastic but if I was in your shoes.....you don't sound like a rookie at this, so you've done the obvious......

I'd completely bleach the tank.....everything, including the gravel. 
Rinse many times and neutralize fully. 

Then start from scratch like it's a brand new tank.......starting a new bacteria colony. 
When things are wierd and going completely wrong you need to start from the beginning IMHO.


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## bolram (May 17, 2011)

Buerkletucson said:


> May sound drastic but if I was in your shoes.....you don't sound like a rookie at this, so you've done the obvious......
> 
> I'd completely bleach the tank.....everything, including the gravel.
> Rinse many times and neutralize fully.
> ...


I second this also *old dude


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## yiorgos (Apr 12, 2009)

Buerkletucson said:


> May sound drastic but if I was in your shoes.....you don't sound like a rookie at this, so you've done the obvious......
> 
> I'd completely bleach the tank.....everything, including the gravel.
> Rinse many times and neutralize fully.
> ...


This is the solution that I think I need to perform. I'm afraid that during my usual "extended vacation" there might had been a "prolonged" electricity outage which "contaminated " my gravel and it has never recovered. This will be a good opportunity to "renew" the decor in the tank and maybe put in live plants and a UPS.


Thank you all!!!


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## yiorgos (Apr 12, 2009)

Manafel said:


> If they have any surface agitation at all, it should provide enough oxygen in the water to sustain a healthy environment


Yes, I have made sure that there is agitation!


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## yiorgos (Apr 12, 2009)

coralbandit said:


> Fish from 2007 would be 7 years old.I find fish to be the opposite of dogs.Where small dogs live longer than large dogs,small fish live/have shorter lives than large fish.Tetras and such lasting 7 years is pretty good!It is always a bummer to lose fish,but if you don't see any signs of disease or other issue(water quality) I would chalk the deaths up to old age.
> As for why new fish can't survive,how do acclimate them to your tank.I have seen many times where fish in the tank will be fine but new additions drop like flies.It is either water quality or acclimation IMO.Is this the tank you want to adjust pH in?


No, PH was never a problem, especially now with one fish inside!!! I was just curious about this chalk method on another "thread" because it sounded really strange to me!!! It's wonderful that we can do that here!!!


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## bolram (May 17, 2011)

Hopefully the refresh of your tank will sort this out for you and get you back on track. Keep us updated on on progress


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## Buerkletucson (Apr 8, 2014)

yiorgos said:


> This is the solution that I think I need to perform. I'm afraid that during my usual "extended vacation" there might had been a "prolonged" electricity outage which "contaminated " my gravel and it has never recovered. This will be a good opportunity to "renew" the decor in the tank and maybe put in live plants and a UPS.
> 
> 
> Thank you all!!!


Good decision IMHO.....
Then you know that your starting out with a good clean tank. 

Good luck...


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