Fish dying by the hour-10 dead in the course of a few days.

Tank
What is the water volume of the tank? 40 gallons
How long has the tank been running? 2 years
Does it have a filter? Aquaclear and powerhead
Does it have a heater? Yes
What is the water temperature? 79
What is the entire stocking of this tank? 20 Rasboras, 3 gouramis, Bolivian ram, 4 Sterbai cories (Please list all fish and inverts.)

Maintenance
How often do you change the water? Once a week
How much of the water do you change? 50%
What do you use to treat your water? Nothing—well water
Do you vacuum the substrate or just the water? Substrate once a month

*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? Master test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 20
pH: 8.2

Feeding
How often do you feed your fish? Once a day/every other day
How much do you feed your fish? Not much
What brand of food do you feed your fish? Xtreme, hi Kari
Do you feed frozen? Sometimes frozen repashy gel
Do you feed freeze-dried foods? Sometimes vibrabites, daphnia, bloodworms, but not often

Illness & Symptoms
How long have you had this fish? 2 years
How long ago did you first notice these symptoms? Friday
In a few words, can you explain the symptoms? Fish dying, mouths open
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?darker, lethargic

Explain your emergency situation in detail.
(Please give a clear explanation of what is going on, include details from the beginning of the illness leading up now)

this is a stable mature tank over 2 years old. Most of the fish are about 2 years old as well. No fish deaths in probably a year. I brought home 2 juvenile Pearl gouramis on Tuesday, they were very active and appeared to be quite healthy. I did my weekly water change on Thursday, and Friday one of the new gouramis and 2 Rasboras died. Then today 7 more Rasboras died. The only thing that has changed is the new fish, but I don’t see any signs of disease. Fish just dropping dead, the only thing I notice is their mouths open before they die. Otherwise parameters are good, temperature is good, I don’t understand. Please help, at this rate my whole tank will be decimated by tomorrow.

 

Wow, sorry this is sort of a bad situation.

1. Do you trust the source of the new fish (you've gotten fish from them before and they are always healthy and disease free?). Some Gourami are known for diseases and being specifically vulnerable due to inbreeding; however, that doesn't explain why the other fish are dying, since the diseases I'm alluding to are localized mainly to Gourami species.

2. Have you tested your water for heavy metals and other solids, well water makes me thing that there could be spikes in minerals and such, but you'd know more than me, just brainstorming here

3. If you have access to RO water from a local pet shop, I would recommend segregation of the new fish from the old fish in RO water until you can understand what is happening, RO water is completely pure, you can at least rest assured on that.

 

Thank you for replying.

1) fish are from petco, it is a well run high volume petco so they are pretty good, I like to go there because they have harder, higher PH well water like my own. I agree about the diseases

2)I had the same thought as you. Especially since the fish started dying after the water change. I considered that maybe I forgot to bypass my water softener as I do every water change, but I specifically remember bypassing. But maybe something did change with my water, testing for heavy metals etc is a good idea.

3) I don’t know if I will be able to get my hands on RO water in time, but it is a good thought to isolate or eliminate the water itself as an issue

anybody else have anything to add? Fish are dropping like flies, any help would be appreciated.
Does anybody have any other thoughts? Any help offered by the community would be really appreciated. I’ve dosed with prime in the meantime in case that helps with possible water issues.
Any gurus help me here? A201 GlennO AvalancheDave ?

 

Bump. I’ve lost 5 more fish. Kindly requesting assistance on this.

 

I'm sorry. It certainly sounds like some disease or parasite came in with the new fish, but other than that I'm afraid I can't help. Hopefully someone else can.

 

Thank you ProudPapa

 

I don't really have any experience with it to speak of, but I have been reading up on columnaris due to a suspected case in my own tank. Some of your description could match the fastest moving strains perhaps. But it could of course be something else too.

 

All I can say on this is to test your tank water for what you can again, and test your source water again. you can rule out things you can fix. multiple fish dying with their mouth in the open position is either ammonia or nitrite poisoning, (Hypoxia and damage from it, and the fish can't uptake oxygen to their blood from the gills) if that isn't indicated in the water test results, then you should look at KH and pH and the possibility of a overnight pH drop from a well aged tank and plants creating too much CO2 and acids and using too much O2 in the dark. causing Osmotic shock and the fish to struggle with the water for the last few days.

if you can rule both of that out, and you can also rule out any chemical being added to the water on accident, new paint with fumes, a misting air freshener, someone getting a little crazy with lysol or chlorox wipes, or pest control bug sprays, things of that nature,......

Well then it's going to most likely be a parasite like gill flukes, gill mites, or something along those lines that's suffocating the fish. not likely to be bacterial or fungal without showing outward physical signs or bacterial or fungal issues.

rule out what you can rule out, and narrow it down and take a best guess at what to treat, inspect a dead fish's gills with a magnifier for damage or stow aways. check in the mouth for swelling or blockages.

 

Thank you SparkyJones that was helpful. My kh is so high I doubt my ph crashed but it’s certainly worth testing both…and interesting theory about the osmotic shock.
I appreciate you taking the time to brainstorm possible causes, oddball stuff like cleaning fluids etc crossed my mind as well…if it is a disease as you say a fungal or bacterial pathogen would manifest physically but maybe a parasite would be harder to spot…

i think some in depth testing is in order and perhaps it is time for me to get a quarantine tank, I never imagined a new fish could wipe out a whole tank but it seems like it could be possible. i will examine the dead fish for gill flukes etc

Thank you everyone for your ideas and advice, it has helped. It’s pretty upsetting and demoralizing to lose my tank like this with all the effort I put into it the last couple years but first thing is I need to find out what happened so I can rebuild

 

It does seem a bit much to be a coincidence for fish you’ve had for 2 years to suddenly start dying off soon after adding new fish. In most cases the disease introduced (often Ich) is quite visible. In this case it’s not which makes it very difficult to diagnose. If you can keep an eye on affected fish and describe in detail their behaviour and any symptoms before they die someone here might be able offer a possible diagnosis.

 

Thank you Glenn. The dying has slowed down fortunately but I lost half the tank. The only dead fish I was able to examine was a Gourami I found yesterday, I don’t see anything in its throat or gills but it’s a bit hard to see. I’ve attached photos. Behavior of the ones I managed to see before they died was a bit of listing, erratic swimming, clamped fins, lethargy, hanging at the bottom, discoloration. Didn’t really see any labored breathing or gasping at the surface. Just a couple I saw with mouths open. But it all happened so fast they would be eating and swimming normally one minute and dead half an hour later. Let me know if that narrows it down at all.

i did do a water change today so we will see how that goes. Thanks for all your help.

 

I’m afraid I have no idea. Many years ago I had an experience where I suspect an internal bacterial disease went through my tank. The symptoms were somewhat similar (with the addition of some gasping), but the fish died over a period of days from onset of symptoms, not within half an hour. That’s something I have not experienced.

 

Although your water is testing great, be a good idea to buy a bottle of Prime water conditioner.
The sudden accelerated fish deaths reflect more of a toxin over a disease.
A virulent strain of Columnaris is a possibility, but that isn't very common.
Oodinium aka Velvet, is a very quick killer once it takes hold & can be a tank killer. If possible view the fish under subdued lighting & look for the tiny powder like Oodinium parasites on the fish.

 

Are there any professional services that can exam your dead fish and tell you why it died?

 

Although your water is testing great, be a good idea to buy a bottle of Prime water conditioner.
The sudden accelerated fish deaths reflect more of a toxin over a disease.
A virulent strain of Columnaris is a possibility, but that isn't very common.
Oodinium aka Velvet, is a very quick killer once it takes hold & can be a tank killer. If possible view the fish under subdued lighting & look for the tiny powder like Oodinium parasites on the fish.

Thanks A201, I do keep a bottle of Prime on hand. I started dosing it on Monday after all the fish died and actually none have died since. I don’t know whether that’s a coincidence or not. On one hand as Glenn said it seems too much of a coincidence that the fish started dying after I added new fish. On the other hand the quick deaths with no symptoms Point more towards a toxin. The deaths stopping after adding prime supports this 2nd hypothesis (perhaps). I did a water change today and all the remaining fish are looking active and eating well.

I’m afraid to stop dosing Prime until I sort this out. Does anybody know if I should dose every 24 hours or 48 hours? I thought the effects of it binding to heavy metals and other toxins lasted 48 hours but I don’t remember.
I will look closely for velvet. Thank you

Are there any professional services that can exam your dead fish and tell you why it died?

That’s a good question, I’ll look into that.

 

I’m afraid to stop dosing Prime until I sort this out. Does anybody know if I should dose every 24 hours or 48 hours? I thought the effects of it binding to heavy metals and other toxins lasted 48 hours but I don’t remember.

 

It binds up ammonia, nitrites and nitrates for up to 48 hours. Not sure about heavy metals.

 

It binds up ammonia, nitrites and nitrates for up to 48 hours. Not sure about heavy metals.

Sodium-Thiosulfate binds Ammonia - yes. Nitrites - debatable. Nitrates - not at all. Heavy metals - known to chelate copper and lead, as well as non-heavy metals like iron.

 

Thanks, I’ll add it every 48 hours until I get this sorted.

 

Prime does 1ppm of ammonia per the dose. My opinion if you can live at the 0.50ppm ammonia or less mark, single dosing is fine. Worse case it's covering at least up to 0.50ppm from hour 24-48. If that looks untenable, double dosing does work and is safe and will get you the 2ppm ammonia, which will start to decline after 24 hours (it's why they say from 24-48 hours in the directions, so people don't push it out to the full 48 hours)

 

Although in this instance I’m not worried about ammonia, that explanation is really helpful. Thank you