# The slow fish die off



## colio (Dec 8, 2012)

I have a 75 gallon heavily planted aquarium with an ehiem 2217 filter. I had it set up in my basement for several months before moving it upstairs and replacing my 65 with this 75 (so a refresh) about 3 months ago. 

I am now experiencing a slow die off of some of my fish. I had a bit of the same problem in my 65. I slowly lost several fishies following the move despite my best efforts to minimize the trauma. Now it seems I loose a fish every 3 or 4 weeks, mostly the smaller ones. I lost a cory cat a while back, and another is surely on his last legs (these cories are well over a year old). I think I recently lost a cardinal tetra, and the last of my fork tailed blue eyes dies before that (they did NOT do well after the change).

I have hard tap water with moderate hard PH (7.6 or so). I manage a 30% water change usually about every 2 weeks. However, my nitrates are quite low (10ppm or so) due to the plants, including water lettuce which grows like mad. I treat my water with pirime. 

I think the tank is fairly healthty. Does anyone have any suggestions on what I can do? Should i run a course of antibiotics maybe? I wuld really like to stop loosing fishies and stabilize this tank. 

Here is the stock:
6 juvi red line torpedo barbs
1 female krib
3 cory cats (soon to be 2)
9 to 11 cardinal tetras, I can't seem to count past 9 these days but they hide sometimes
1 opaline gourami (my oldest and favorite fish, not aggressive)
2 bristlenose plecs
some amano shrimp

Params: PH 7.6, water moderately hard, nitites 0, nitrates 10 ppm even 2 weeks after last water change, some amonia reading but I seem to get a lot of false positives on that test, moderate CO2 (checker is green), lots of plants, fish fed once per day. 

If anyone has any ideas please feel free to share : )


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## Bullet (Apr 19, 2014)

Puzzling 
Corys are pretty hardy so if they go then that would indicate a big problem IMO
You shouldn't have any ammonia at this point 
Over feeding maybe ?


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## colio (Dec 8, 2012)

Bullet said:


> Over feeding maybe ?


I dont feed that much, and the red lines are fast eating piggies.


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## brycon (Aug 5, 2014)

How do you do your water changes?


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## colio (Dec 8, 2012)

brycon said:


> How do you do your water changes?


Python, adding extra prime before I refill. Temperature close to tank but tending colder rather than warmer.


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## SKurj (Oct 26, 2011)

I asdd just enough prime to do the whoel tank as I refill with the python, I have heard too much prime can reduce oxygen levels.. I do 1 cap full for a 55g, 4 caps for a 180g.

Could there be something else, like a pollutant or anything? Old food? anyone else touching the tank? dirty hands?


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## Bullet (Apr 19, 2014)

Dead fish trapped somewhere undetected in the tank ?


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## tom g (Jul 8, 2009)

*new tank deaths*

hey there .. when I had my freshwater tank I had similar probs and for no reason at all , it just seemed no matter what I did or tried to do any fish I added to tank would just disappear ....
im not sure if this is like a new tank syndrome or something it took me a good while till the tank settled down and I had no losses . not sure if that helps or not just be patient and if u are doing things as u say u are doing things right .
good luck


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## Bullet (Apr 19, 2014)

I'm happy to offer refuge space in one of my tanks for your livestock - except shrimps


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## ameekplec. (May 1, 2008)

Is there a chance you have parasites or some other pathogen in your tank? I know back when I had worms and I didn't know, I'd have fish that were a little small or getting skinny then croak. Wasn't till I saw the worms sticking out a fishes butt that I realized and I treated with an antithelmintic.

The other possibility is that fish just get old, and the ones with the shortest lifespan tend to be the smaller fish. My dad's tank is reaching the end of one life cycle where all the various rasboras and tetras I bought for him years ago are now cataract covered, slow old fish soon to croak.


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## colio (Dec 8, 2012)

ameekplec. said:


> Is there a chance you have parasites or some other pathogen in your tank? I know back when I had worms and I didn't know, I'd have fish that were a little small or getting skinny then croak. Wasn't till I saw the worms sticking out a fishes butt that I realized and I treated with an antithelmintic.
> 
> The other possibility is that fish just get old, and the ones with the shortest lifespan tend to be the smaller fish. My dad's tank is reaching the end of one life cycle where all the various rasboras and tetras I bought for him years ago are now cataract covered, slow old fish soon to croak.


I am concerned it may be some sort of pathogen or parasite, as I had the same issue in my 65 gallon tank, including loosing a few bosemani rainbows. I don't think it is ageing as many of the fishies are only around a year old or so.

Any good suggestions for what I can do to treat potential silent parasites or pathogens?


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## Merman (Nov 23, 2009)

*Let it Age*

Don't automatically assume you have a disease if you don't have any signs of one. Dumping chemistry into your water is just going to jolt an already stressed system further. I could be wrong but from what I've read so far I get the feeling that you may not be leaving things at rest and giving them time to re establish.

I think your fish are getting stressed out from your moving them. If you only do 30% water changes every two weeks then your fish get accustomed to that for a while and then suddenly when you move them you're upsetting them from an established tank to a 'new' one. Tanks need to fully mature as well and they are very different from a tank you've only had set up for a few months. A lot of your fish die off is probably due to this reason - it depends on how much effort you put into maintaining as much of the established water/gravel/filter material from your old tank...you may not have done this.

Also, when you do water changes don't go slightly colder - always go slightly warmer. Fish get shock from colder water as opposed to warmer water.

I hope this helps.


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## tom g (Jul 8, 2009)

*agree*

I agree with above , sometimes we put too much into what we think is goin on 
let the tank mature , don't add anymore fish try to keep it as stable as possible .my tank took me a good year to stop the die offs ...


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## pyrrolin (Jan 11, 2012)

It could be a couple simple things. A loss of good bacteria during the move could have caused ammonia and or nitrite spikes you didn't see causing enough damage that they suffered internal damage that is catching up to them but not enough of a spike to kill them fast.

Could also just be the stress of being moved caused damage to lower their life.


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