Fish dying one by one - Cycled tank

The original fish were fine. New fish were added. The new fish started dying a day or two after they were bought. Fish have continued to die since then. The new fish were guppies?

Guppies are riddled with diseases like bacteria, protozoa, gill flukes and worms.

There might be a water quality issue too, possibly caused by the dead fish, but I reckon the new fish brought in a disease.
 
Spot on w/ the Guppies; Im so over buying them. I'd go with females Bettas, I find them much more versatile, pretty and robust.
but like my wife, temperamental when provoked.
 
Hahaha, now that I get...except mine needs no provocation.
My last two victims are still alive as are all the guppy fry...slight ammonia reading 0.25 or something but nothing else
 
Your nitrite and ammonia levels are high. I suggest a large water change, and maybe grab some API StressCoat, API StressZyme, and some API AquaClear. The coat will help make your tap water safer, the zyme will help add good bacteria and the clear will help rid of bad bacteria.

I also suggest you do not add any new fish for at least 3 weeks. Do a large change today, 50% or more. Then do 2 small changes, every Wednesday, about 25%. Retest, then see if your levels are star. If they are, slowly add fish, maybe 2-3 every 10 days TOPS. Recheck the water before getting new fish. I would also suggest getting a small quarantine tank for new fish. I have had many issues with sick fish from local pet stores. Now I only shop at 1 because I know the family, and I know how they handle the fish.
 
I have had many issues with sick fish from local pet stores. Now I only shop at 1 because I know the family, and I know how they handle the fish.
Same - I reckon you want an independent shop and steer clear of Franchise stores. The chap I frequent now, first time I went he he was cleaning tanks, doing water changes. He has a small but great range of fish. Most of my current community are from him, and are happy as pigs in sheissen.

I also seconded the API range - quality gear.
 
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I vote for the theory that the new fish introduced a disease and started the situation and the loss of beneficial bacteria in the filter media caused a mini cycle and worsened things.

Lessons learned:
1. It’s a good idea to quarantine new fish before adding them to your established tank
2. Don’t ever replace all of your filter media at one time (or do anything that will kill it all like adding a medication to the main tank that harms beneficial bacteria—unless it’s a last resort)

What to do now:
I think if it were me I’d continue with the daily large volume water changes until ammonia and nitrite are reading zero while there’s any fish still alive. If any fish survive I would wait until your nitrogen cycle is balanced again and then consider adding in new fish slowly (after quarantining first). If all the fish die I would just start over from scratch since your biological filter has taken a hit anyway and there’s the question of whether there’s a contagious microbe of some sort in the tank.

….in my opinion
 
What symptoms did they have if you noticed any?

New fish especially guppies and tetras tend to be riddled with disease.
 
All fish have diseases, the fish in your tank are not stressed so they don't show the symptoms of disease. I'm sure the fish at the pet store showed no symptoms of disease. But the fish get chased around a tank, then put in a plastic bag, placed in an unfamiliar environment and the fish gets stressed and you have a disease outbreak. Please don't blame the Pet stores for all your problems, pet stores don't have disease riddled fish. If they do, why are you buying the fish and taking them home?
 
That question was asked and answered already
Yeah and the answer was too vague to make any sort of educated guess.

So far I gathered;
Lumpy bodies on tetras
White in the poop.

In terms of lumpy tetras that sounds like microsporidia/type of neon tetra disease.
White in the poop could be anything from internal parasites to TB.
If they aren't getting emaciated or dropsy or leisions, I'd lean toward internal protozoa like Hexamitam
 
Please don't blame the Pet stores for all your problems, pet stores don't have disease riddled fish.
I have to disagree with this. Whilst most shops have mostly healthy tanks with few diseases in, most shops do get sick fish. The two main aquarium fish wholesalers/ suppliers in Australia used to send us sick fish all the time. Other wholesalers did it too. We would order in 200 guppies and they might be fine but there were plenty of times we had dead fish in bags when we opened the eskies, and there were plenty of bacterial and protozoan infections on fish that we just received. The suppliers did credit/ refund us for DOA's (dead on arrival) and if we sent them pictures of sick fish that just came in, whilst still in the sealed bags. But they all send out sick fish to the shops. They shouldn't but they do. It's all about the money. Their customers want fish. The wholesaler has some fish that are sick but need to supply their customers. So they send them the healthiest fish out of the sick tanks. The diseases get spread to the shop that way.

Shop tanks that aren't cleaned regularly will also get diseases.

This is not to say that customers have perfect tanks. Many have water quality issues or diseases and the problems come from all sides (wholesalers, shops & customers).
 
I have to disagree with this. Whilst most shops have mostly healthy tanks with few diseases in, most shops do get sick fish. The two main aquarium fish wholesalers/ suppliers in Australia used to send us sick fish all the time. Other wholesalers did it too. We would order in 200 guppies and they might be fine but there were plenty of times we had dead fish in bags when we opened the eskies, and there were plenty of bacterial and protozoan infections on fish that we just received. The suppliers did credit/ refund us for DOA's (dead on arrival) and if we sent them pictures of sick fish that just came in, whilst still in the sealed bags. But they all send out sick fish to the shops. They shouldn't but they do. It's all about the money. Their customers want fish. The wholesaler has some fish that are sick but need to supply their customers. So they send them the healthiest fish out of the sick tanks. The diseases get spread to the shop that way.

Shop tanks that aren't cleaned regularly will also get diseases.

This is not to say that customers have perfect tanks. Many have water quality issues or diseases and the problems come from all sides (wholesalers, shops & customers).
Are the fish sick before they go in the bag, or do they get sick in transit? That is the question.
 
Hahaha, now that I get...except mine needs no provocation.
My last two victims are still alive as are all the guppy fry...slight ammonia reading 0.25 or something but nothing else
Hi there, what symptoms did the fish have very specifically?

So far it seems like the tetras had lumpy bodies and the other fish had some white in their poop.

Is there any other details you could add?

Were they still eating?

It's possible to guestimate what parasite or infection it is but it requires a lot of symptom detail.
 
Are the fish sick before they go in the bag, or do they get sick in transit? That is the question.
The ones we got were sick when put into bags and sent to us. The suppliers were just greedy and didn't want to lose sales.
 

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