I have no idea what happened and I'm so upset. I have a 6-7 month old 20 g planted tank. It (was) the home to two gourami, six neon tetra, 5 Corys, 3 cobra guppies and 3 mystery snails. The guppies were new last week but everything else has been happily existing for several months with no problems.
They were fed this morning and everything was fine. I spent several minutes looking at the tank yesterday evening with no problem. This afternoon, everything was dead except the gouramis and the tetras. All six tetra seem to be totally fine (a clue?). The gouramis are struggling, lethargic and gasping at the surface. Everything else is dead.
Ammonia read at .225 and nitrites were zero. Temp was 83.3. could be a heater malfunction? I turned it off and added some ice cubes in the hopes of saving the gouramis.
No recent water changes or additions. No new plants or fertilizer. Does anyone have any ideas of what happened or what I can do to save the remaining fish?? I'm in shock and so sad. Ty in advance
Posted by DestinysAFickleBitch
19 Comments
Sounds like they were boiled
83 isn’t too hot for those fish short term. I would run heaters at 86 for 2 weeks to treat ich with those species. The ammonia is fatal. A small tank with few live plants may not be able to handle the ammonia produced from a single decomposing fish and this may have caused more deaths if not removed within a couple of hours. The more plant growth you have, the more stable the system becomes as plants remove ammonia.
So sorry to hear that. It could be possible when you introduced the new guppies to the tank they could have been carrying ich or there was bacteria in the water with the guppies from the fish store. Do any of the fish have small white dots on them?
ideally run 2 heaters that arent capable on themselves of heating the tank too much. That way if/when one malfunctions, the other will compensate and give you time to remedy the situation.
Ammonia spike may be due to the death of fishes, so a good water change ( avoid tap water if you can, otherwise use conditionner and heat the water before putting it in) may help. gasping at the surface can be due to a lack of oxygen but you have air stones in there so thats no that. Probably ammonia poisoning.
Get more fish
Buy this thing:
https://preview.redd.it/1vkhrb41vddg1.jpeg?width=1110&format=pjpg&auto=webp&s=3b55504c807ccadc8c7cbbb7f4c2a8364f5f25f3
Ammonia can spike when you least expect it. This little thing is very helpful to detect changes 24/7.
could be paint leeching into the water from your decorations and rocks
Your aquarium looks decent. What has been the average temperature of your aquarium since you set it up 6-7 months ago?
I keep a temperature of 24°c which would be 75.2f
What temperature was your heater set to? Was it fully underwater when you came?
I suspect the heat was too much for one of the species, maybe the corys, they often like a bit lower temps. When they started dying it made the situation worse by releasing ammonia. Also rotting materials, such a dead fish, pull oxygen from the water. In addition hot water is worse at holding oxygen, so maybe that was also part of it.
Ofcourse it’s also possible that it was unrelated to the heat and that the guppies carried a disease or disrupted the balance. Though if the tank was stable before it should have been able to handle three more small fish. Maybe it was on the brink of flipping anyway?
Take all the dead fish out, get a new heater if it is indeed broken, change water and you should be fine
Had you fully cycled the tank before putting fish in? Also need way more live plants to cycle the nitrites into nitrates to keep away ammonia.
Anything higher than 0 for ammonia is deadly for fish.
Prime stabilizers etc help hugely, and plastic decor often leak paint that contains ammonia, keep it more natural in future 💙
my guess is that the guppies brought something into the tank – some kind of infection or parasite rather than ich or something visible, one of your fish succumbed to it and then the decomposition spiked your ammonia.
Any chance something was inadvertantly introduced into the tank? Room spray, ammonia based cleaner, windex, hand sanitizer? Any kids in the house? Any company withing the last 24 hrs?
Sorry this happened OP.
I’m not an expert . On the contrary , I had many fish perish under my care but I cant imagine one dead fish causing that much ammonia to kill everyone else … I left a dead fish in my tank for days (he was under some plants) and the rest of the fish were just nibbling on him like he was a snack .
Has anyone else been handling the tank and maybe put something in it that they were supposed to ?
Sounds like an ammonia bomb 🙁
The sudden mass death makes me think some sort of outside chemical got in there. Was originally thinking maybe electrical issue too, but it would be odd for only some of the fish to be taken out by that. The temp isn’t even close to high enough where it would cause this much death, but a heater with a faulty wire or heating element definitely could. Your ammonia is obviously super high but that’s more than likely the result of this and not the cause, especially if things were looking normal yesterday.
Definitely look into any sort of chems getting in there, and sorry for your loss either way.
Too much plastic in the tank, bacteria like to live in porous material, and it can colonize it better. Add some rock or wood or both to the tank. Add porous bio media to your filter.
you shouldn’t be getting any ammonia reading, any ammonia present is toxic to fish. seems like your cycle failed for some reason or not enough bacteria was present to process the dead fish safely. Add api quick start or other nitrifying bacteria for the next few weeks before adding more fish
EDIT- thank you everyone for your help. It’s been a sad afternoon but I have a little hope for trying again.
I scooped out my struggling gourami and put them in a temporary home until I can do a total water change tonight. They appear to be doing much better in there. Maybe they can be saved. I initially said my heater was set to 80 but it appears to be set at 76. Not sure if it’s a calibration issue or what. It’s currently off.
I’m removing the decor and adding more plants while I’m doing the water change. Then I’ll fill it back up, dechlorinate it and let it warm up before adding the gouramis back tomorrow. I’ll keep testing until my ammonia is back to 0 before I get anymore fish.
I appreciate everyone’s advice! I’m still not totally sure the cause. The housekeeper was here today and maybe some cleaning agents got in there on accident. I can’t emphasize enough how it went from fine to catastrophic in a matter of hours. What a fickle hobby we enjoy. Best of luck to you and your tanks!
The fact that the deaths happened simultaneously could be a hint. Ideas that come to mind are: (1) The higher the temperature, the less oxygenation and your tank was heavily stocked. It could also explain why some fish survived because they could breath again once the others died. (2) Did you do any glass cleaning with Windex? Any Odor fresheners being used in the room? I think option 1 is more likely.