Fish dying one by one - Cycled tank

[Colin_T]

the new fish brought in a disease, it has nothing to do with the tank or pH.

 

[suicidal_maniac]

Colin Colin Colin, don’t do this to me! The guys have now convinced me it’s water quality or cycle crash, I thought it was a disease/ parasite to begin with, now I think it’s probably both

 

[Ch4rlie]

the new fish brought in a disease, it has nothing to do with the tank or pH.

What is this based on?

How have you arrived to this conclusion?

 

[Deleted member 149562]

To me this is looking like a basic aquarium crash that may have been building for a while either due to an incomplete initial cycle and/or a water/husbandry issue...the introduction of the new fish could well have pushed the crash over the edge but I do not believe that the new fish brought a parasite or illness into the aquarium, they just shattered the unnoticed and already fragile ecosystem within the aquarium

 

[NannaLou]

I’m sorry this is happening, it’s always upsetting losing the fish, and when something you’ve worked hard to develop goes wrong.

I’m not anywhere as knowledgeable about diseases etc as @Colin_T and others that have posted so I’m not going to enter that bit of the debate.

I do think your water parameters are out based on your photo of the tests you did, I definitely think there was ammonia and nitrite showing as being present. Who knows whether these readings might have been a little bit higher at other times?

Looking at some of your other photos, the plants definitely don’t look healthy, there’s a lots of black on them and in the photos in post #44 there is algae (mould) of some kind all over the glass and plants.

I think it’s going to be a case of stripping it all back to step one and starting again so you know the inside of the tank is good and the next batch of fish will be safe.

Have you got anything else (largish plastic tub) that you could put the remaining fish in with the heater, filter and a large handful of floating plants and do a mini-fish-in cycle while you fix up the tank..? Would that keep them safer..?

 

[Guest14017]

the new fish brought in a disease, it has nothing to do with the tank or pH.

This actually could be the case - he said the new fish died first, and slowly the rest begun to get ill and die. He replaced the filter medium when the deaths begun to occur thinking it may help - but this caused the cycle to crash, which will only accelerate the deaths of the already weakened fish. May have been a bacterial issue that just begun to spread around the tank.

 

[Fishfinder1973]

How much of the original stick are still living?

 

[Fishfinder1973]

Stock,not stick lol

 

[suicidal_maniac]

I have an endlers guppy who seems to be immune to whatever's going on, and one female guppy who is surviving at the moment but I think she is infected with whatever it is.

There's also about 10 guppy fry in there as well who seem fine.

My take on it is this

The tank stock was fine for the time leading up to the new fish being added, no deaths or illnesses in the previous months.

The day after the new fish were added one of the new fish died, then during the next week the other new fish died, then my original fish started to get ill and I panicked and did the filter change which upset the cycle.

So I'm leaning towards I introduced some sort of disease or parasite then crashed or bumped the cycle. I think the disease/parasite is still there and I'm treating with NDX.

I could set up my spare tank, but as I did the filter change nearly a month ago I think by the time I get another tank ready the cycle will have recovered in the existing tank.

I think I keep going trying to get the water back in spec in the existing tank, and hope the cycle recovers

 

[Guest14017]

If you suspect virulent disease - it may be best to nuke the entire system. Any new fish added will be infected too. When KHV or fish TB is confirmed or highly suspected for example - all the fish in the affected system are destroyed and it is specially cleaned before using again.

You only have a few fish left anyway and your plants are all dead/dying. I definitely would close this system to new fish for several months at least if I decided to keep the remaining stock.

 

[fishyfun&fans]

you crashed the tank-sorry for your losses.

although the plants help maintain the balance in a cycled tank and help slightly with cycling.

they still needed the good bacteria from the filters created in the initial tank cycling as that's essential to life in the aquarium

ideally you could of changed 2 of them waited a week or 2 then changed the others.

this is somthing you know now and that's great

as for the bumps they could of been all manner of things and could of been diagnosed sooner if you had of contacted TFF when they appeared or looked them up on the internet

end of discussion

 

[Bruce Leyland-Jones]

the new fish brought in a disease, it has nothing to do with the tank or pH.

I'm curious...what is your evidence for that?
From a thorough review of the posts, it appears that there was a potentially fragile system in place, that became unbalanced by the addition of the new fish. These didn't need to be diseased.
The subsequent actions of this inexperienced fishkeeper, as he himself suggests, exacerbated the problems, which caused a complete system crash and it was swiftly downhill from there.

A painful lesson, to be sure, not least for the fish, but one that could be clouded by an unevidenced conclusion.

 

[Ch4rlie]

This actually could be the case - he said the new fish died first, and slowly the rest begun to get ill and die. He replaced the filter medium when the deaths begun to occur thinking it may help - but this caused the cycle to crash, which will only accelerate the deaths of the already weakened fish. May have been a bacterial issue that just begun to spread around the tank.

Admittedly this is what I thought at first but then began to see that there was more to this than that.

It’s all too easy to blame it on new LFS stock added to your tank, and this stock was ‘diseased’ or full of parasites, easy to think this. I say, well, not quite, I’ll bet you the tankmates of same fish at LFS are still alive and doing ok despite LFS conditions.

Impossible to prove at the moment of course.

But then looking at the tank itself, just looking at the Marino moss balls alone, those are almost black, this did not happen overnight, this is likely down to tank water parameters or poor maintenance. And looking around the tank itself, not exactly squeaky clean and lots of algae. Apologies to OP but this is what I am seeing from the photos he provided.

So therefore the old tank stocking had sort of ‘adjusted’ or got ‘used’ to the slowly eroding water parameters over time and built up a sort of resistance to this but by no means immune.

So the addition of new stocking, they of course are not used to these water conditions and therefore got ill and sadly passed and this ultimately started the chain reaction of the crashing water parameters and the mistake of changing the filter media which exacerbated the situation resulting in the deaths of the older tankmates.

Hence why I thought OTS, not conclusive but this makes sense to me.

It MAY be down to LFS stock bringing in a parasite or disease but overall this is not what I think is singly the case, might be a contributing factor perhaps.

 

[Guest14017]

@Ch4rlie
See that makes sense too - addition of new fish further upset an already upset system and tipped the scales, resulting in losses. It's impossible to be sure at this point BUT he said the fish show no obvious signs of illness before dying. This points to a water quality issue more than a disease issue. But it isn't a certainty. All such a mystery.

 

[fishyfun&fans]

its certain alright this guy fluffed up by crashing his tank

the fish diseases should of been the OP'S top priority BEFORE ANY FILTER CHANGES