Why are all my fish dying?

[Fishy Novice]

We bought a Siamese fighter with 6 tetras (not sure of their name but they had a leopard spot to the back fin) which were doing ok. After 2 weeks we bought some neon tetras and other type of gold tetra. However, after 5 days, one of the gold tetras died and over the course of 4 days all the rest (including the original Tetras) have died leaving just the Siamese fighter. The original tetras did start looking as though they had some white spots and their fins seemed to be looking less healthy. I've done a water test which showed the NO3 and potassium were only slightly of concern. Please can anyone suggest what the problem is as we would like to buy more fish once we know what the problem is.

 

[shellieca]

When you say Siamese Fighter you are refering to a Betta fish, correct? Male or female? Bettas are really picky about tank mates and very well could've killed off your other fish. How big of a tank do you have? Bettas, especially Males, are known to be aggressive & if your tank isn't very big that could exacerbate the problem. My two male Bettas are in individual 10g tanks with their only tank mate being a mystery snail. When I first put the snails in I believe my Bettas picked on them but after a day or two things settled down. However, I wouldn't put any other fish in with them in their 10g tanks, but that's just me. if you want to introduce other fish, depending on the size of your tank, you may want to look into bottom feeders.

 

[Fishy Novice]

Not sure if it's male or female. We've got a 45 litre tank and we were told by the shop where we bought the fish that Siamese fighters were fine with any fish other than their own kind.

 

[tarpon]

My betta is fine with other fish in a 10 gallon. I actually believe he'd be much more "bored" without other fish to interact with.

What did the body's of the dead fish look like?

 

[Fishy Novice]

Some were furry, others looked no different but it looked like all the fins had been nibbled a little.

 

[tarpon]

It couldve been neon tetra disease. If a fish eats the flesh of a tetra that is carrying the disease then that fish will die. And fish will often nibble on their dead buddies.

But have you done a full water test? Ammonia? nitrite? nitrate?
and what are you testing with?

I'd go ahead and do a large water change for your betta

 

[shellieca]

Not sure if it's male or female. We've got a 45 litre tank and we were told by the shop where we bought the fish that Siamese fighters were fine with any fish other than their own kind.

If I'm not mistaken 45 litres is around 10g. I think you may have had two problems, being overstocked & a Siamese who didn't like all those fish sharing his space. I'm guessing from what the store told you, you have a male which tend to be more aggressing IME. Most, but not all, of the members here will tell you not to put any tank mates with a Siamese especially in a 10g tank. I would suggest doing some research as to what type of tank mate a Siamese is most likely to tolerate, then see if they are appropriate for a 10g (45 litre) tank. Lastly, is your tank cycled? I couldn't tell from your post how long it has been running. Are you testing your water with a liquid test kit or strips? It's VERY important that your ammonia & nitrItes are at zero. With the amount of fish you had, there was probably a too big bio load for the 45 litre which may have contributed to the deaths. Just some things to consider.

 

[hpiguy]

That seems like a lot of fish for a 12 gallon tank. 45 liters is 11.8 gallons, without gravel and decor.

 

[hpiguy]

Some were furry, others looked no different but it looked like all the fins had been nibbled a little.

Some were furry?

Sounds like they were left in the tank dead so long they started to rot/mold/decompose.

In such a small tank even one rotting fish will ruin the water and kill other fish, let alone a few allowed to get that bad.

 

[Fishy Novice]

All my fish have died

So now all my fish have died except for my Siamese Fighter. I think they were diseased as they all seemed to develop white spots about 12-24 hrs before they died. They all seemed to lose their back fin too.

Any ideas? Is it likely they were diseased before I bought them or do all the fish in the tank catch disease quickly? Why hasn't my Siamese Fighter died?

 

[Fishy Novice]

Thanks for all your replies. I did a water test and found all was ok except NO3 and KH were on amber. I think that the neon tetra were probably diseased as all was well until we introduced them to the tank. It would seem that we were wrongly advised as the store told us we could have up to 25 small fish in the tank.

I think the reason some of the fish were furry is because about 12 of them died whilst we were away for the weekend so they could have been dead for up to 3 days.

I'll certainly do more research on what's best to go with a Siamese Fighter. Any suggestions? And what would be the maximum number of fish for this size tank? Would you suggest sticking to fish that only grow to about 5 cm or get fewer larger ones!

 

[shellieca]

Thanks for all your replies. I did a water test and found all was ok except NO3 and KH were on amber. I think that the neon tetra were probably diseased as all was well until we introduced them to the tank. It would seem that we were wrongly advised as the store told us we could have up to 25 small fish in the tank.

I think the reason some of the fish were furry is because about 12 of them died whilst we were away for the weekend so they could have been dead for up to 3 days.

I'll certainly do more research on what's best to go with a Siamese Fighter. Any suggestions? And what would be the maximum number of fish for this size tank? Would you suggest sticking to fish that only grow to about 5 cm or get fewer larger ones!

Unfortunately not all employees at an LFS are knowledgable & will steer you very wrong. You're tank while not the smallest isn't big enough for large numbers of fish & with your Siamese your options are a little limited. In my experience it's best to get a kind of bottom dweller as they look different from a Siamese & they won't invade his space so much. You may want to post a thread in the general discussion forum asking others to give their advice. I don't have other fish with my male Siamese in their 10g tanks, they each have a Mystery (apple) snail & for me that is plenty. In my 46g I have 3 female Siamese, 2 Chinese Algae Eaters & 2 snails. I know I could add more & at some point I might but I'm a little overly cautious about overstocking.