What Could Have Happened To My Fish?

[tealover351]

hey guys, sorry i haven’t been super active on here i’ve just been going through a lot at the moment. i recently lost nearly all my fish I had in a 100 gallon tank and i’m really at a loss for what happened. to start off i installed the tank on a stand, put some sand in it, two airstone, some rock caves, tons of live plants, a filter, heater, thermometer, lights, and a background. before adding any ammonia chloride in i treated water with seachem prime. i was working really hard on it with cycling terms adding dr tims pure ammonia chloride in and frequently using the api freshwater master test kit. i also brought over some sponge from my filter in an established tank that has been up for about a year, the fish in it showed no signs of disease and are still alive, happy, and healthy. i added bottled bacteria as well. it took roughly a month maybe a little over (i will attack screenshot of cycling i used). i added in fish slowly starting first with a red tailed shark, then two weeks later periodically adding in tiger barbs until i had 12 all schooling together happy, i also, roughly two weeks later, added in periodically, buenos aires tetra. i added in about 5 mystery snails as well. i don’t remember my exact water readings but they were never of concern as i tested twice a week and did one water change a week of about 25 percent of the water. the water set out in a bucket for a couple days before being tested and then added into the tank, i also vacuumed my gravel every time as well. all my fish were fine for about two months, as far as i could see no fighting, signs of disease, weird behavior, or anything of the sort they were all happy and stress free. then one morning when i went to feed my fish i noticed one of my barbs were missing i looked around for him but couldn’t find him anywhere he had been fine the night before he ate well and was swimming and acting normal. i fed all my other fish and had to leave for work but before i left i watched everyone eat and everyone was perfectly fine. i found him before leaving and removed him, he had died but showed no signs of injury or disease. i also tested water and remember no ammonia, nitrite, nitrate, kH, gH, and pH and everything was fine no change. fast forward about three hours my younger sister texts me and tells me all my tiger barbs had died, despite being fine and eating normally that morning he reported that he had fished them out and some had red spots right in front of their anal fins whereas others didn’t. sad i asked him to remove them from the tank and he did just that. when i came home a few hours later i noticed that all my buenos aires tetra were dead besides three and my red tailed shark had passed on to. i quickly did a water change and removed the fish and retested water everything was still good. my remaining tetra are still alive and acting normal. the only thing i noticed was that some of the tetra had the same red dot as the barbs. does anyone have any ideas, i know sometimes fish die but this seems like a lot at once to just be coincidental, any other stuff you guys may need let me know i can’t give exact numbers but that is what i have for you. i have no photos of fish since they all died.

 

[tealover351]

i also lost the snails too. all of them were dead for sure that smell was horrid.

 

[Colin_T]

Without pictures and video of the fish, it's impossible to say.
However, if the tank was established, and it sounds like it was.
And if the fish were fine for a few weeks before this started.
And if no new fish, plants, shrimp or snails were added within 2 weeks of this starting.
And if you didn't do a water change the day before this happened.
And if you use the same food for both tanks.
The most likely cause of a lot of fish dying in a 24 hour period is poisoning from something.

You may have had something on your hands that contaminated the water, or someone else might have put something in the tank.

Is the filter and heater working properly.
Have you had visitors in the last 24 hours?
Does anyone smoke, paint, use aerosols or do anything in the room that produces fumes or smoke?
Do you use hand sanitiser?

 

[tealover351]

Yes, my filter and heater are all good. At the time when this went on, I had no visitors or anyone in my house as far as I knew. Before interacting with the tank I run my hands under hot water to kill off any germs. No smokers, however the room next door to the fish room we have was being repainted by my mom, I kept the doors to the fish room closed during that time to try to protect them. No sprays used either, and I usually don’t use sanitizer even with covid because it tends to hurt my hands as my skin is quite sensitive. Could that room being painted effected them? I know it can be hard to kind of figure this out without pictures or videos, so the reply is much appreciated Sorry I took a little bit to respond.

 

[Madisonkeug]

Yes, my filter and heater are all good. At the time when this went on, I had no visitors or anyone in my house as far as I knew. Before interacting with the tank I run my hands under hot water to kill off any germs. No smokers, however the room next door to the fish room we have was being repainted by my mom, I kept the doors to the fish room closed during that time to try to protect them. No sprays used either, and I usually don’t use sanitizer even with covid because it tends to hurt my hands as my skin is quite sensitive. Could that room being painted effected them? I know it can be hard to kind of figure this out without pictures or videos, so the reply is much appreciated Sorry I took a little bit to respond.

Sorry for your loss! always heartbreaking when you lose a bunch like that especially when you can’t find what you’ve been doing wrong. It may simply not be your fault at all... The red dot could a parasitic nematode common in pet stores. Did you treat or quarantine any of the fish with generic medications before adding to your tank? Might have been the issue here Possibly look into camallanus specifically!

 

[Colin_T]

If the paint was water based it's less likely to be an issue to the fish. However, if the paint was turpentine (oil) based, it could have caused or contributed to the problem. Having said that, if the doors were shut and you don't use air pumps on the tanks, it is unlikely to be paint fumes. Fumes normally get into aquariums by being sucked in from an air pump.