20 Gallon Tank Something killed all my fish

clownie99

I have a 20 gallon tank. It is cycled and I always keep up with water changes.

I went out for about an hour this morning and fed my fish before I left. They all ate and seemed fine. I came home about 20 minutes ago and noticed them all dead. 8 false julii corydoras 6 black skirt tetras and 3 gardneri killifish. They all had a weird white film on them.

I tested the water and parameters were all perfect, even hardness and ph hadn't changed. I am thinking someone sprayed a toxic chemical near the fish tank. Or is there something else that could have killed them?
 

BVUBeavers

Any chance the temps of the water changed dramatically? Sorry for your loss, that sucks.
 

carsonsgjs

Any pictures of the tank and fish? What makes you think it was a chemical?

Perhaps the emergency template might be helpful here, so we have the full picture.
 

Demeter

Any photos of the dead fish? The white film is probably their slime coat, that is a response of stress and irritation. What were the number results for ammonia, nitrite and nitrate?

Toxins are a good guess. Did you have anything on your hands when you fed them? I accidentally killed a bunch of baby shrimp when I fed their specimen container after putting lotion on (I swish my finger to make the food sink). The fry in there were fine but all the shrimplets had croaked over night.

Spayed chemicals could certainly be a suspect but usually the lid should keep them safe from that. Ask the other people in the house if they sprayed anything around the tank.
 

clownie99

Any pictures of the tank and fish? What makes you think it was a chemical?

Perhaps the emergency template might be helpful here, so we have the full picture.

Any pictures of the tank and fish? What makes you think it was a chemical?

Perhaps the emergency template might be helpful here, so we have the full picture.
Okay here you go.

Tank
What is the water volume of the tank? 20 gallons
How long has the tank been running? Around a year
Does it have a filter? Yes
Does it have a heater? Yes
What is the water temperature? 25°C
What is the entire stocking of this tank? (Please list all fish and inverts.) 3 gardneri killifish 8 false julii cories. 6 black skirt tetras

Maintenance
How often do you change the water? every 4-5 days
How much of the water do you change? 25%
What do you use to treat your water? Seachem prime
Do you vacuum the substrate or just the water? Substrate and water

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? Api liquid test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 10
pH: 6.8

Feeding
How often do you feed your fish? Every day
How much do you feed your fish? About a pinch usually
What brand of food do you feed your fish? Fluval bug bites
Do you feed frozen? Yes twice a week
Do you feed freeze-dried foods? Yes once a week

Illness & Symptoms
How long have you had this fish? Had the cories for about 3 weeks
How long ago did you first notice these symptoms? Today
In a few words, can you explain the symptoms? Just dead, white film on them.
Have you started any treatment for the illness? No
Was your fish physically ill or injured upon purchase? No
How has its behavior and appearance changed, if at all? No
Any photos of the dead fish? The white film is probably their slime coat, that is a response of stress and irritation. What were the number results for ammonia, nitrite and nitrate?

Toxins are a good guess. Did you have anything on your hands when you fed them? I accidentally killed a bunch of baby shrimp when I fed their specimen container after putting lotion on (I swish my finger to make the food sink). The fry in there were fine but all the shrimplets had croaked over night.

Spayed chemicals could certainly be a suspect but usually the lid should keep them safe from that. Ask the other people in the house if they sprayed anything around the tank.
Yeah I am guessing someone sprayed something. The white film has gone so they just kind of look like dead fish. I smelt the water and it smells sweet so I think a chemical somehow entered the tank.
 

otterblue

That really sucks. I feel bad for you.

I had a whole tank die like that. Mine was a faulty heater boiled them. Or maybe your food was contaminated.
 

clownie99

That really sucks. I feel bad for you.

I had a whole tank die like that. Mine was a faulty heater boiled them. Or maybe your food was contaminated.
Yeah its the worst feeling. Thanks everyone for your help
 

OutsideFoodBlob

I’m so sorry to hear this happened. Are the fish in a common area in the house? Somewhere that others might use an aerosol spray like air freshener, perfume or cleaning products?
To have a mass die off like that is really unfortunate to say the least. Again so sorry and I hope you are able to pin point what caused it.
 

clownie99

I’m so sorry to hear this happened. Are the fish in a common area in the house? Somewhere that others might use an aerosol spray like air freshener, perfume or cleaning products?
To have a mass die off like that is really unfortunate to say the least. Again so sorry and I hope you are able to pin point what caused it.
Thank you. I am guessing fly spray. The water smelt just like the brand my family uses.
 

OutsideFoodBlob

Unless it was an elderly relative, I’d find it hard not to at least brandish a rubber slipper anytime anyone even looked at the fly spray for the next couple of days.
Again, I’m sorry this happened to you and your fish. I hope this doesn’t discourage you from the hobby.
FWIW: I have challenging relatives that I live with. The common sense is not strong with them. Have averted at least two fire hazards in the last two months. If you need to strategize protecting future fish from a similar situation pop on here and ask.
 

clownie99

Unless it was an elderly relative, I’d find it hard not to at least brandish a rubber slipper anytime anyone even looked at the fly spray for the next couple of days.
Again, I’m sorry this happened to you and your fish. I hope this doesn’t discourage you from the hobby.
FWIW: I have challenging relatives that I live with. The common sense is not strong with them. Have averted at least two fire hazards in the last two months. If you need to strategize protecting future fish from a similar situation pop on here and ask.
Yeah I'm almost entirely sure it was my grandmother trying to spray some bug on the lid of the tank. I have moved the tank into my room for now to avoid anything like this again. It's quite hard to stay angry at someone who had no idea. Definitely not quitting the hobby or anything, just a learning point I suppose.
 

OutsideFoodBlob

Oh no! And yes, I agree it’s hard to be or stay mad at an older relative. I think moving the tank was a good idea. If you have carbon you could try running that in your filter and water changes to clear tank of any lingering chemicals. For the tank surfaces that might have residue: vinegar water or hydrogen peroxide (not together). It would be a real shame to have to break the whole thing down and start over.
 

clownie99

Oh no! And yes, I agree it’s hard to be or stay mad at an older relative. I think moving the tank was a good idea. If you have carbon you could try running that in your filter and water changes to clear tank of any lingering chemicals. For the tank surfaces that might have residue: vinegar water or hydrogen peroxide (not together). It would be a real shame to have to break the whole thing down and start over.
Okay, thank you so much!!I did a 70% water change and have just put some carbon in the filter. The smell is completely gone.
 

aquariumwt

That's too bad to know. Sorry for your loss. Have you tested your aquarium water? If possible please share images.
I feel it's ammonia issue, but images would help a lot
 

Similar Aquarium Threads

Replies
3
Views
116
DoubleDutch
Replies
45
Views
2K
FreshwaterPhotog
Replies
3
Views
165
Fisheye
Replies
12
Views
435
BeardedTetra

Random Great Thread!

Latest Aquarium Threads

Top Bottom