Fish Dying

[copperhead]

I have a 29 gallon aquarium I was given three months ago. It was established and partially stocked with two tiger barbs and three black fin tetras at the time. After the first month I began adding a few fish. Three weeks ago I quit adding fish. There were two blue rainbowfish, 3 blackfin tetras, 6 tiger barbs, and 12 neon tetras.  Four days ago one of the blackfin tetras died. It had very frayed fins. Since then 3 of the tiger barbs have died. I am thinking mebbe a agressive fish is to blame. One of the remaining tiger barbs is a bit nippy so I removed it today and put it in a temperary tank. I am thinking mebbe it is killing/stressing the other fish? I check ammonia, nitrite, and nitrate weekly before the water changes. Ammonia and nitrite have always been zero since the first week I had the tank. Nitrates were 80 ppm at first, but have not been over 20ppm in over a month. Water temp is 78 degrees. Any idea on what is causing the problem? Thanks in advance.
 

 

[Bubbelzzz]

At first, welcome to this forum!
 
Only looking at you stocking, I can see a few problems. At first, your tiger barbs (Puntius pentazona), should be kept with a lot more fish. These are very active and playful fish. When they are not kept in a large group they are more likely to harass other fish. This will mostly happen with fish that have long fins such as for example angles. However, this doesn't mean they will leave fish with smaller fins alone. So this could explain the shredded fins. This behavior in turn causes stress to the fish and might lead to to death.
 
This fin nipping behavior can also be seen among blackfin tetras (Gymnocorymbus ternetzi), especially towards each other. This can be overcome by keeping a larger shoal as well. As 3 isn't really a shoal.
 
Based on your story is my guess that the stress of being chased by others eventually killed your fish. However, some pictures of your tank and the fish might make it easier to determine the exact cause.
 
At last, do I want to note that your tank isn't very properly stocked. As your tank is 29 gallons (approximately 110 liters) I t is too small for the blue rainbowfish (Melanotaenia lacustris), which also need to be kept in a shoal (so 6 or more). I would recommend to move them to a bigger tank.
Furthermore, do the G. ternetzi be kept with a larger shoal as well as the P. pentazone (both mentioned above). But it might be better to move them out of the tank as well. Since, especially the P. pentazona can be very tricky to care for properly. The neon tetras are fine, they have a nice shoal.
 
Of course it doesn't look good if you only keep the neontetras. So you might like to add some other fish, for example corydoras species. But in case you decide to restock your tank, you might want to open a separate topic on this.

 

[the_lock_man]

I broadly agree with the sentiments of Bubbelzzz, the tank is overstocked, and there are some compatibility issues.
 
The main thing I see is the tiger barbs. Barbs are shoaling species, and we normally recommend any shoaling species to be in a group of at least 6 and preferably more. Tiger barbs are, imo, different, because they are a very feisty species (I wouldn't say they were playful. Evil, yes

). Generally, I would recommend keeping them in a shoal of at least 10-12, as this will usually keep the aggression between themselves (and therefore not affect the other species), and will also not usually lead to one individual being unduly bullied. Remember that in the wild, these fish live in shoals that number in hundreds, and sometimes thousands.
 
This aggression will, as stated, lead to elevated stress levels in the other fish. Stressed fish become susceptible to disease, and disease, obviously, leads to death.
 
LIkewise, the overstocking will also elevate stress.
 
Recommendations Difficult to say right now, without knowing which species you particularly want to keep. If you can let us know the priority, then we can advise further.
 
Just one final note, in case anyone starts getting confused. Bubbelzzz has used an incorrect scientific name for Tiger Barbs. They are properly called Puntius Tetrazona, not Puntius Pentazona. The latter fish (common names being Pentazona Barb or Five Banded Barb) looks incredibly similar, although it has one more black band on its body, but the major difference is that it is a very docile fish, completely different to the evil tiger barb. If anyone were to search for information on p.pentazona thinking they were researching the Tiger Barb, there would be some confusion as to the temperament of the fish.

 

[Bubbelzzz]

Just one final note, in case anyone starts getting confused. Bubbelzzz has used an incorrect scientific name for Tiger Barbs. They are properly called Puntius Tetrazona, not Puntius Pentazona. The latter fish (common names being Pentazona Barb or Five Banded Barb) looks incredibly similar, although it has one more black band on its body, but the major difference is that it is a very docile fish, completely different to the evil tiger barb. If anyone were to search for information on p.pentazona thinking they were researching the Tiger Barb, there would be some confusion as to the temperament of the fish.

 
I'm so sorry, you're totally right. This happens if you try to multitask. Indeed tiger barbes are P. tetrazona (tetrazona, is not with a capital letter though).
As tetra means 4, the tetrazona has 4 bars and penta meaning 5, the pentazona has 5 bars.
My apologies, I should have known better.

 

[the_lock_man]

 

Just one final note, in case anyone starts getting confused. Bubbelzzz has used an incorrect scientific name for Tiger Barbs. They are properly called Puntius Tetrazona, not Puntius Pentazona. The latter fish (common names being Pentazona Barb or Five Banded Barb) looks incredibly similar, although it has one more black band on its body, but the major difference is that it is a very docile fish, completely different to the evil tiger barb. If anyone were to search for information on p.pentazona thinking they were researching the Tiger Barb, there would be some confusion as to the temperament of the fish.

 
I'm so sorry, you're totally right. This happens if you try to multitask. Indeed tiger barbes are P. tetrazona (tetrazona, is not with a capital letter though).
As tetra means 4, the tetrazona has 4 bars and penta meaning 5, the pentazona has 5 bars.
My apologies, I should have known better.
 

 
The pedant in me wants to point out that if the second part of the scientific name does not have a capital letter, then equally a scientific name should be italicised. But that would be just childish of me. So I shan't point that out at all. No. Definitely not.
 

 
All is good 

 

[Bubbelzzz]

 
 
 
 
The pedant in me wants to point out that if the second part of the scientific name does not have a capital letter, then equally a scientific name should be italicised. But that would be just childish of me. So I shan't point that out at all. No. Definitely not.
 

 
All is good 

 

 
Hahaha, yeah that's totally true 

 

[Ltygress]

AND IN OTHER NEWS, aside from the penta and tetra.... lol

You MAY also be looking at a disease introduced by one of the new fish. That's why it's not only important to add fish slowly, but to quarantine any new fish you get to make sure they are healthy. Petsmart and Petco have notoriously high turnover rates, and will remove sick fish completely out of sight without ever treating the aquarium, which keeps the employees AND customers from seeing MOST sick fish while they are in the care of the store.

That means most times when you get the fish home, it will probably die from whatever disease it has picked up in their tanks.

Keep in mind that most pet shops in general also use a central filtration system. The tanks all have overflow in the back where the top of the water spills into pipes leading into one giant vat. There the water is "filtered" through mechanical, chemical, and biological filtration. The vat ALSO has a water level control valve that automatically fills it back up when the water gets below a certain point. This, in turn, gets pumped back into the individual tanks (which won't "spill over" into the pipes unless THEY are full enough).

The problem is ONE SICK FISH will contaminate the entire system. There is no isolation. So even if the wholesaler has healthy fish, it just takes one sick fish to come in to their store and every fish that is there at the same time, or after that, will also contract the disease. And those stores are not ABOUT to treat the entire system at once (can you imagine the price tag on the amount of medication they would need??)

That's also why you don't see the fish getting sick at their store. They are being introduced to the disease at the store, but not actually getting sick until you take them home. AND that's why quarantine for no less than 2 weeks (preferably closer to a month) is required for any new fish you bring in.

 

[Byron]

I second what other members have said, including my welcome.  Ltygress is certainly correct on the disease matters, but given the species mentioned I think the problem is less one of disease and much more likely the species and numbers.  You need to decide which fish you really want, and then find another home for those you don't.  I needn't repeat what has been said about the barbs, tetra and rainbows, it is all correct.
 
Byron.

 

[copperhead]

Thanks for the advice. I was out of town for a few days and two more of the barbs died including the most agressive. None died after the first day though. Today I was able to return the two remaining barbs where I bought them. I will probably remove the black skirt tetras and the rainbows if I can find somewhere to take them. Don't want to flush such pretty fish... I think I'm going to do a soft water community tank when I restock...

 

[Byron]

Do you know the water parameters of your source water (tap presumably)?  You can ascertain the GH (general hardness, the most important for fish), KH (carbonate hardness or Alkalinity) and maybe pH from your municipal water authority on their website, or directly.  Some soft water fish are more adaptable than others.  The fish mentioned initially here are fairly adaptable except for the neons, long-term, but knowing the parameters will allow you to choose suitable fish with more success.
 
Byron.