# fish still dying weeks after correcting water chemistry..



## Efishency (Nov 29, 2010)

hello everyone
i have wrongly not payed enough attention to my tanks before, resulting in >50mg/L nitrates. my supplier has said this is too high for the specific species im keeping (garra rufa) and in irder to bring them down i did frequent water changes with treated tap water instead of the ro water i had in before because that wasnt an option at the time. basically the fish have gone through ph fluxes (7.3 up to 8.2) in periods less than 48 hours. the species is also pretty aggressive towards sickly individuals, picking them out at any sign of weakness. these guys are bottom feeders/scrapers. i have been losing up to 10 a day (started out with hundreds) over the last few weeks. it has been probably 10 days since the ph is now stable and nitrates near zero. still getting dead fish. i have noticed bloody paches on some, mostly on their side but a few round the mouth areas, which im also afraid might be due to bacterial infections following stress. etc.

so...

im guessing the cause of the deaths is the water chemistry stress, possibly leading some to infetctions, although some dead fish dont have red patches. the way it is going i am going to lose all with in the next couple of months. is this a case of post stress mortality? how long can it co on for?

i am desperate for help guys. i have attached a pic of 2 of the dead fish.


Thanks for helping!


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## NeonShark666 (Dec 13, 2010)

Fish don't like sudden changes either ph, temperature or hardness. This produces stress and susceptability to sickness. Your fish need some environmental stability. I advise you to run an external filter with a charcol filter, run vigorous aeriation and make no water changes for at least a month. Remove dead fish as soon as you can. You say your nitates are near zero. This can't happen with all the fish in your tank. Take some water to your fish shop and testg it.


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## jrman83 (Jul 9, 2010)

I don't agree with that. Frequent water changes with as many fish he has in the size tank he has is the ONLY way his fish will be healthy.

To back up some, what size tank was it again. Wasn't it initially like 300 fish in a 55g tank?

Ph fluctuations brought about by adding/not adding RO water shouldn't have hurt your fish as it is a natural rise/lower. If you have been putting in any kind of ph up/down, that can cause severe ph issues - they don't work for very long and only maintain to the changed value for a very short time before going back to the original value. Also, trying to add 100% RO water is not good either. RO water usually has zero hardness or kh. Your kh is what helps you maintain your ph...stirp it all away and you have a tank that fluctuates a lot and will eventually kill your fish.

Can you just give a history of what you've been doing? Start with what you have for tank, temp, filtration, amount of fish, feeding habits, etc... And then tell us what type of maintenance you've been doing for water changes, chemicals added, filter changes, etc..? I think that could help.


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## susankat (Nov 15, 2008)

It wouldn't be a natural rise if it happens all of a sudden at a water change. Adjusting fish to a different ph needs to be done slowly over a course of time. Big ph swings can cause a lot of stress and will affect the fish long term. That many fish in a tank will need lots of water changes to keep toxins down, but with the differences in ph it will need to be done slowly by changing a little bit everyday and a little more than the last each time.


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## jrman83 (Jul 9, 2010)

Yeah...I was making an assumption. I do 50/50 RO/tap for my water changes. Only affected my ph .5 initially. Now it just maintains the value.


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## Gizmo (Dec 6, 2010)

How many of these fish do you have in the tank? Those autopsy results sound like wounds from fighting, especially between scavenger fish.


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## Efishency (Nov 29, 2010)

Started off with 3 tanks:
360L – 400 fishes. 15L trickle filter
300L- 400 fishes. 4L trickle filter
160L-200 fishes. 2L trickle filter

Acceptable stocking densities for these fishes are up to 2 fish per litre, according to suppliers. These guys are small, and when I received them they were 2cm each. Initial tank parameters were approx. pH 7.3-7.5; kh 4; gh 5. For the first 3-4 weeks, all was fine, feeding them twice a day. Did water changes: 25% every 2 weeks with tap water (ph 8-8.3; kh 10; gh 11). Did this to acclimatize them slowly to local tap conditions as this is more feasible than ro water. (In Cyprus we don’t have the luxuries of great aquarium stores with ro water supply and the water lost in ro production is an issue here, as we have bad droughts).
Leaving the water exchange just to that raised the nitrates too high. Had a few fish die then and the only thing I could attribute it to was the nitrates. I tried nitrate absorbing resins, but no major difference, so I inserted ‘rooted lucky bamboo’ in the filter units which I found on youtube can successfully remove nitrates. I found that the ph levels went up from around 7.8 at the time, to 8.2 over a couple of days max, so I removed them, thinking that the bamboo could have influenced ph. Fish also appeared with red inflammations which I thought could be signs of aggression or stress induced disease. These guys are always hungry. Some of the dying fish though had not red markings. I was desperate believing it was nitrate stress, so I decided to completely change the water with fresh tap water and move them all in the 360L tank, 2 months after getting the fish. I know this is a no no, but losing $20-30 worth of fish daily was a panic situation. The ph of the new tap water was 8.1, kh-9, gh-10. I tried to match the temperature which I think I did. Added the fish and things continued as they were, a few dying every day and the ph went up to 8.3 in a day or so (degassing of tap water I assume). 
At the moment, the remaining fish, around 300+ are behaving normally as always, eating aggressive;y and going about their business, but then I pick out average 5 dead fish everyday, and not just the smaller ones, but some of the bigger ones. I would think if it was strictly aggression due to hunger, they would pick out smaller ones. I added a uv, feed them both their feed twice a day, which I enrich with vitamins and give cucumber snacks in order to minimize their hunger. These guys can eat forever, and that’s why they are used in fish spas. 
What I have in mind is to continue the feeding regime and do small water changes every couple of days with ro/tap water. This way I will try to maintain the ph8.1-8.2, which isn’t ideal but hopefully stable. The red markings are often similar between the ones that have them, essentially bloody skin taking up sometimes a fifth of the fish length on one side, not just a single nibble-size mark. I think these are infections. Putting these guys in a treatment tank without biological filtration for a few days is possibly a bad idea considering their feeding aggression which might end up them eating each other.

Would greatly appreciate any help on whats going on and how to fix the problem.


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## NeonShark666 (Dec 13, 2010)

Here in the NW facilities that would try to keep 300 fish alive in a 55G tanke are called Salmon or Trout hatcheries. They keep young Salmon and Trout alive with masive and continous water changes and aeriation. The source water is very low in Nitrates and other nutrients and cold. Salmon and Trout are extremely sensative to bad water quality. They are the Cold Water version of the Discus.


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