7 mysteriously dead oscars

[Venoryk]

Water Parameters:

• pH - 7.4
• Nitrates - 5ppm
• Hardness - 180ppm
• Nitrite - 0ppm
• Ammonia - 0ppm
• KH/Buffer - 180ppm
• Water Temperature - 78

Various oscars, 2 spotted Raphael catfins, banjo catfish, and a spotted pictus catfish in a 40 gallon quarantine tank with a 90 gallon rated HOB... treated with the trinity when they got added into the tank. Tank had been quick cycled taking media and decor from an established tank and tested daily for the first 2 weeks. In quarantine for about a month and was in the process of getting the permanent tanks set up to move them in the next 2 weeks. Went to look at them on my lunch break and everything was fine, no signs of distress, signs of any aggression, or illness. 3 hours later, get off work and go to take my stepson to work and 4 previously, seemingly healthy fish are laying dead in the bottom of the tank. Immediately move all fish to a second established quarantine tank and test the water parameters giving the results listed above... over the next few hours the fish start sinking to the bottom of the tank and swimming erratically in short bursts before sinking again and within 30 minutes of showing any signs they are dead. All 4 catfish appear to be unphased, no signs of anything after 3 days having passed since all of the oscars died. 

 

Completely at a loss here, none of my other tanks have been affected and are on the same water change cycle and upkeep. Help me make sense of this tragedy?!

[Zenzo]

On 8/19/2021 at 1:42 PM, Venoryk said:

Water Parameters:

• pH - 7.4
• Nitrates - 5ppm
• Hardness - 180ppm
• Nitrite - 0ppm
• Ammonia - 0ppm
• KH/Buffer - 180ppm
• Water Temperature - 78

Various oscars, 2 spotted Raphael catfins, banjo catfish, and a spotted pictus catfish in a 40 gallon quarantine tank with a 90 gallon rated HOB... treated with the trinity when they got added into the tank. Tank had been quick cycled taking media and decor from an established tank and tested daily for the first 2 weeks. In quarantine for about a month and was in the process of getting the permanent tanks set up to move them in the next 2 weeks. Went to look at them on my lunch break and everything was fine, no signs of distress, signs of any aggression, or illness. 3 hours later, get off work and go to take my stepson to work and 4 previously, seemingly healthy fish are laying dead in the bottom of the tank. Immediately move all fish to a second established quarantine tank and test the water parameters giving the results listed above... over the next few hours the fish start sinking to the bottom of the tank and swimming erratically in short bursts before sinking again and within 30 minutes of showing any signs they are dead. All 4 catfish appear to be unphased, no signs of anything after 3 days having passed since all of the oscars died. 

 

Completely at a loss here, none of my other tanks have been affected and are on the same water change cycle and upkeep. Help me make sense of this tragedy?!

Wow, I am sorry that you lost your fish. Very sad. It is unusual for the fish to all die so suddenly like that. A few things come to mind:

- Is it possible that someone inadvertently put something in the tank (child, etc.)?

- Was there a recent water change and maybe you didn't dechlorinate?

- Is there anything in the tank that could have poisoned them (like a broken heater)? Or even an electrical current from a broken heater or powerhead?

 

[Venoryk]

No kids in the house to have put anything in there.. just the Mrs and I... I did do a water change Saturday on all of my tanks but to make sure that I don’t forget the declorinator I dose out the prime into a syringe and leave it on the lid to the tank as I drain the tanks so that I have to pick up the syringe in order to fill the tank back up. I thought about stray current from the heater or HOB on the tank, but not measuring anything with my multimeter either... I pulled the heater and cleaned and inspected it and don’t see anything jumping out at me.. glass isn’t broken and the rubber boots are in place. I thought about maybe my water company upped the dosage of chlorine, but if that were the case surely one of my other 11 tanks would have had fish die. Just seems to be the 1 tank and have not the slightest clue what the culprit is.

[Colu]

It an odd one if it was something getting into your tank such air freshener or cleaning products or chorine you would have expected to have effected all the fish in that tank the fact that it only affected the Oscars is odd how old are the Oscars what were you feeding them how long after you treated them with meds did they die 

[Venoryk]

On 8/19/2021 at 7:44 PM, Tankseeker said:

@Venoryk very puzzling indeed, has the ph changed? Did you add salt?

Ph runs pretty steady between 7.2-7.4 depending on the tank.. I never saw any swings when I tested, though doesn’t mean it didn’t at some point.

 

On 8/19/2021 at 9:33 PM, Colu said:

It an odd one if it was something getting into your tank such air freshener or cleaning products or chorine you would have expected to have effected all the fish in that tank the fact that it only affected the Oscars is odd how old are the Oscars what were you feeding them how long after you treated them with meds did they die 

Yeah, given that there’s 4 tanks in that corner of the room and all get the same cleaning... no chemicals to clean just a scraper and a glass cleaner sponge thing that came with my extendable glass scraper.. looks like a mr clean magic eraser... if it had been something to get in the tanks I would have expected it to affect more than just the 1 tank and would have affected the 3 kinds of catfish that were in the tank as well. Then again, I would think that regardless of what the culprit was, it would have also had some sort of affect on the catfish that were in the tank as well, but they are still all doing well. 

I hadn’t salted the tank since the first week I put them into the quarantine tank and have been doing weekly 50% water changes, the same as the rest of my tanks.. The oscars got from the pet store when they were about 1” and they were pushing 2.5-3”... they were fed a mixture of like 4-5 kinds of cichlids foods as well as frozen cichlids diet and dried shrimp, mealworms, crickets, a pea or 2 on occasion, probably something I’m forgetting... hadn’t been any meds in the tank for about 3 weeks or more.  There has to be something that I’m overlooking, either that or was just a bad batch of oscars that had some parasites the paracleanse didn’t take care of or something... but, never saw any when treating for the 1st week so didn’t do a full follow up, just dosed the tank once and let it stew for the 2nd week.

[Colu]

Nothing jumping out at me it a difficult one

[Venoryk]

On 8/19/2021 at 10:07 PM, Colu said:

Nothing jumping out at me it a difficult one

Me either.. and sucked finding that just the day before my bday of all times.. so, can guess what my bday was spent doing.

[Hobbit]

Oh man, I’m so sorry. That’s rough.

Since the catfish aren’t affected, I can only guess that it was something the oscars ate and the catfish didn’t, or a virus/bacteria/parasite that is specific to oscars. I’m not an disease expert by any means, but the fact that they went downhill so quickly says to me that there was a super acute problem like poisoning or a really fast-acting disease.

Regardless of what it was, I don’t think you did anything wrong. Sounds like a fluke to me. It still stinks though.

[Mmiller2001]

Do you feed those live feeder fish?

[Venoryk]

On 8/20/2021 at 3:24 PM, Mmiller2001 said:

Do you feed those live feeder fish?

They were too small to begin with, but no.. don’t do feeder fish. Also have 5 turtles and know how bad feeders are. If at any point I were going to do feeders would be a livebearer that I raised and know there’s no health issues and that it’s been fed a nutritious diet.