I Watched All My Fish Die Right In Front Of Me.

Please help. I would like to correctly diagnose how this happened.

All I wanted to do was a standard water change.

Never did I think three hours later it would be a fatal disaster.

I'll mention as a side note, that my mystery snail died recently, so I knew there was nitrate buildup in my aquarium. I also have cyanobacteria, but the fish seemed to be doing perfectly fine, even with that in there. Since my snail died, my tank water stank a nasty odor. I'm not sure what it was, but it couldn't have been nitrates. Nitrate levels were normal. It didn't smell like a pond anymore, but like something rotted died in there.

I could smell it across the room, with my open hood aquarium.

I did my regular routine: fill up a bucket of filtered water, and then pre-treat it before it went into the tank. I put in ammonia reducer, and tap water dechlorinator. (I also put in nitrate remover for the dead snail issue). This routine has never given me problems before. I've been doing it since I've gotten my fish from the store two months ago. They all seemed perfectly perky, healthy, and happy every time I did it this way.

However, I noticed that my plant leaves were pretty discolored, so after pruning them, I also added a SMALL amount of CO2 booster. I realize that might have been a huge mistake.

About an hour later, one of my neon tetras started swimming like it was disoriented. This got my attention. Never did my fish do this before, so I studied its behavior for a moment. It was struggling to reach the surface, gulping in air, and twirling around, finding out which way was up. I took a quick water test, and nitrates were normal. There was no ammonia. pH was a bit high, so I put in a small dab of pH Down. But even that didn't work. It was squirming, and fighting for breath, twirling around, like it was dizzy. So I thought maybe the water temperature was too high and cooking their insides.

So I checked the temperature. 79.5 degrees fahrenheit. That was fairly high, but it's June, but they have been alive and kicking in 78 degree water before. Regardless, I put some ice cubes in a plastic Ziploc bag, and set it in the water. It went down to 79.3. It helped, but I don't think that was the issue.

My neon tetra slowly lost its battle, and floated to the bottom of the tank. I watched the color fade from its body. It died right there. I then got this feeling that it about to get bad with the rest of my tetras. The rest of them were bigger. They might not have felt the effects yet.

Sure enough, twenty minutes later, all of my 19 neon tetras started doing the same thing. They swam like they were disoriented, squirming for the surface. I had no idea what to do. It was about an hour battle of trying to save them, but they just all slowly lost consciousness and died. One got stuck to the side of the filter, being so weak, and just letting the filter suck it in place.

So I turned the filter off for a second, let it swim free, and then turned it back on. But the filter then wouldn't come back on. So I couldn't even agitate the surface to get more oxygen in there. I tried taking it off, unjamming it, and it still won't come back on.

All of my fish are dead, now. I watched them all drift to the aquarium floor, and slowly die a painful death. I tried to comfort them as they passed away. I looked at them, sympathetically stroking a finger to the glass, and they looked at me, like they sort of knew I was there. I made sure they knew I was there before they passed on.

Anyone who loves their pets are sad to see them in misery. It was like watching a dog that got hit by a truck, die in your arms... 19 times. It was horrible. After one last attempt at putting a bucket of clean, filtered water in there, there was nothing else I could do. I have a video of the event, and I believe it's this tetra's last moments alive. (VID_20180627_134519)

I issue this as a warning to any fish keepers who use CO2. I didn't even know what it was until this happened. If you have a planted tank, you must have patience, as I've learned. After this, I'm not sure if I'll do live plants anymore, and get the cheap plastic ones instead.

Does this sound/look like CO2 poisoning? Everything else I did was my normal routine. All the fish in these photos are dead/barely alive.





EDIT, 6/28/18: I found a major clue. It has to do with my snail dying. I found out when a decomposing body dies underwater, it is called anaerobic decomposition, as opposed to aerobic, like how it happens on land. Which means in anaerobic decomposition, oxygen can't get to the body to decompose the corpse, so it breaks down into hydrogen sulfide instead. I found out that hydrogen sulfide is quite notorious for being a quick killer in living things.

I found out that symptoms of acute exposure to hydrogen sulfide include "nausea, headaches, delirium, disturbed equilibrium, tremors, convulsions, and skin and eye irritation. Inhalation of high concentrations of hydrogen sulfide can produce extremely rapid unconsciousness and death." Hydrogen sulfide is the same stuff you smell in well water, from waste treatment plants, and sewer drains.

From OSHA's website, it says that moderate to high concentrations of hydrogen sulfide include:

• Moderate concentrations – more severe eye and respiratory effects, headache, dizziness, nausea, coughing, vomiting and difficulty breathing.
• High concentrations – shock, convulsions, unable to breathe, coma, death; effects can be extremely rapid (within a few breaths).

This would explain a lot. It sounds a lot like what my fish were doing.

So what I did during my water change, basically, was kick up all of that hydrogen sulfide sitting at the bottom of the tank from my dead snail, up to the surface, where the fish were breathing. They finally felt the effects of my dead snail, and couldn't handle the gases, I suppose.

I hardly couldn't. When I took a whiff of the filter, I clapped a hand over my mouth and nearly retched. There's this overpowering fumey smell that punches you in the face. Never again will I purchase a snail. I never want to deal with this again.

What gets me, is that I already removed the snail body from the tank. I had no idea gases from a decomposing body would still effect the fish.

 

I'm so sorry to hear about all your fish dying. I'm really sad for you.

I think you have several things going on that contributed to your fishes death. Do you happen to know what the ammonia, nitrite, nitrates and pH were for your tank before all this happened? Also, I'm in the Hoosier state too and I've been having water issues at my house right now.

 

Honestly it sounds like you’re doing too many things to try to help your fish. One could argue where you could have just used prime, you used like a half dozen different remedies and treatments. I applaud your investment of supplies and attention to your fish, I really do, but you are introducing more variables and possibly causing more problems than you’re solving with so many chemicals. Keep us updated, and I’m sure others will have more to say, I readily admit to not being an expert. It’s just my opinion that things are being over treated.

I want to edit to add that I’m very sorry for your loss. I had something similar happen to me with 10 cardinal tetra, In my case I believe it was from over eating unsoaked freeze dried tubifex. You had the best of intentions, that is a true horror to go through.
With so many variables introduced I’m not sure you can pinpoint co2.

 

I'm so sorry. Any chance your tap lines are being flushed or cleaned? That can release heavy metal deposits, or it can increase the amount of chlorine to the level that a normal dose of water conditioner wouldn't be enough.
I'm really sorry about your losses, that had to have been very painful. I had a similar thing happen recently, so I understand, at least to some degree.

 

Please help. I would like to correctly diagnose how this happened.

All I wanted to do was a standard water change.

Never did I think three hours later it would be a fatal disaster.

I'll mention as a side note, that my mystery snail died recently, so I knew there was nitrate buildup in my aquarium. I also have cyanobacteria, but the fish seemed to be doing perfectly fine, even with that in there. Since my snail died, my tank water stank a nasty odor. I'm not sure what it was, but it couldn't have been nitrates. Nitrate levels were normal. It didn't smell like a pond anymore, but like something rotted died in there.

I could smell it across the room, with my open hood aquarium.

I did my regular routine: fill up a bucket of filtered water, and then pre-treat it before it went into the tank. I put in ammonia reducer, and tap water dechlorinator. (I also put in nitrate remover for the dead snail issue). This routine has never given me problems before. I've been doing it since I've gotten my fish from the store two months ago. They all seemed perfectly perky, healthy, and happy every time I did it this way.

However, I noticed that my plant leaves were pretty discolored, so after pruning them, I also added a SMALL amount of CO2 booster. I realize that might have been a huge mistake.

About an hour later, one of my neon tetras started swimming like it was disoriented. This got my attention. Never did my fish do this before, so I studied its behavior for a moment. It was struggling to reach the surface, gulping in air, and twirling around, finding out which way was up. I took a quick water test, and nitrates were normal. There was no ammonia. pH was a bit high, so I put in a small dab of pH Down. But even that didn't work. It was squirming, and fighting for breath, twirling around, like it was dizzy. So I thought maybe the water temperature was too high and cooking their insides.

So I checked the temperature. 79.5 degrees fahrenheit. That was fairly high, but it's June, but they have been alive and kicking in 78 degree water before. Regardless, I put some ice cubes in a plastic Ziploc bag, and set it in the water. It went down to 78.3. It helped, but I don't think that was the issue.

My neon tetra slowly lost its battle, and floated to the bottom of the tank. I watched the color fade from its body. It died right there. I then got this feeling that it about to get bad with the rest of my tetras. The rest of them were bigger. They might not have felt the effects yet.

Sure enough, twenty minutes later, all of my 19 neon tetras started doing the same thing. They swam like they were disoriented, squirming for the surface. I had no idea what to do. It was about an hour battle of trying to save them, but they just all slowly lost consciousness and died. One got stuck to the side of the filter, being so weak, and just letting the filter suck it in place.

So I turned the filter off for a second, let it swim free, and then turned it back on. But the filter then wouldn't come back on. So I couldn't even agitate the surface to get more oxygen in there. I tried taking it off, unjamming it, and it still won't come back on.

All of my fish are dead, now. I watched them all drift to the aquarium floor, and slowly die a painful death. I tried to comfort them as they passed away. I looked at them, sympathetically stroking a finger to the glass, and they looked at me, like they sort of knew I was there. I made sure they knew I was there before they passed on.

Anyone who loves their pets are sad to see them in misery. It was like watching a dog that got hit by a truck, die in your arms... 19 times. It was horrible. After one last attempt at putting a bucket of clean, filtered water in there, there was nothing else I could do. I have a video of the event, and I believe it's this tetra's last moments alive. (VID_20180627_134519)

I issue this as a warning to any fish keepers who use CO2. I didn't even know what it was until this happened. If you have a planted tank, you must have patience, as I've learned. After this, I'm not sure if I'll do live plants anymore, and get the cheap plastic ones instead.

Does this sound/look like CO2 poisoning? Everything else I did was my normal routine. All the fish in these photos are dead/barely alive.

View attachment 450793 View attachment 450794

Can you list the specific products you used? All of them?
You said everything but the co2 was routine but what about the nitrate reducer in the new water and using ph down? Sometimes tinkering with the ph artificially can cause problems. Could it have caused a ph fluctuation or a side effect from the chemical?

I just feel like we have to look at this scientifically. Also the series of additives you use being routine doesn’t make it less relevant, there may be interactions or conflicts with a single additional chemical in play. Again I don’t know what those would be but I wouldn’t discard the possibility when trying to figure out this tragedy.

 

Honestly it sounds like you’re doing too many things to try to help your fish. One could argue where you could have just used prime, you used like a half dozen different remedies and treatments. I applaud your investment of supplies and attention to your fish, I really do, but you are introducing more variables and possibly causing more problems than you’re solving with so many chemicals. Keep us updated, and I’m sure others will have more to say, I readily admit to not being an expert. It’s just my opinion that things are being over treated.

I want to edit to add that I’m very sorry for your loss. I had something similar happen to me with 10 cardinal tetra, In my case I believe it was from over eating unsoaked freeze dried tubifex. You had the best of intentions, that is a true horror to go through.
With so many variables introduced I’m not sure you can pinpoint co2.

It's okay. I agree that to some degree, a fish enthusiast freaking out about disoriented swimming makes them try too hard. But what gets me, is that I did absolutely nothing different from my normal routine. All I did was add nitrate reducer and CO2 booster. That was it.
I may have to agree with RedLoredAmazon, now that they mention it. I only had a vague idea of what the ammonia, nitrate, and pH levels were before I did the water change. I didn't think it would end up being so drastic. But thank you all for the kind condolences. Life goes on, I guess. I tried. I really did.

 

It's okay. I agree that to some degree, a fish enthusiast freaking out about disoriented swimming makes them try too hard. But what gets me, is that I did absolutely nothing different from my normal routine. All I did was add nitrate reducer and CO2 booster. That was it.
I may have to agree with RedLoredAmazon, now that they mention it. I only had a vague idea of what the ammonia, nitrate, and pH levels were before I did the water change. I didn't think it would end up being so drastic. But thank you all for the kind condolences. Life goes on, I guess. I tried. I really did.

What about ph down?

 

I'm so sorry you're going through this. I don't have any explanation, but I do agree with Willed, it sounds like you're adding too many things and trying to over correct. If your pH had increased it would have been more beneficial to to figure out why it had increased; if it had consistently been high it would be better to let your fish adapt to the new conditions rather than try to correct it with chemicals. I've been told that adding a pH corrector is more harmful than letting fish adapt as it usually causes swings in the other direction and leads to an unstable pH as it will go back up (or down) once the chemical is gone.

I do truly sympathize with you though, I'm currently trying to figure out why 16 of my fish have died. Fingers crossed we both figure out the problems with our tanks/fish!

 

I have to agree that you are putting way too many chemicals in your tank. I also would not add ice to quickly cool a tank down. They appear to be dying of shock which leads me to believe it may be water temp related. Do you know what the temp was before the water change? If it was more than 2 degrees lower than what you replaced it with then that would put them in shock. I’ve done that once myself by mistake. I would recommend checking your water temp before a change and making sure the same temp is going back in. I am truly sorry for your loss.

 

That's awful! I'm so sorry. I really hope this doesn't deter you from keeping fish in the future.

That said, I do agree, the amount of chemicals you add to your tank is concerning. You should generally only be using one product when you change water, a water conditioner. You are using several products to do the work that one good brand of water conditioner would do on it's own. Like Seachem Prime. Prime helps detoxify ammonia, nitrite, and nitrate, in addition to removing chlorine and chloramine. And it's just one product, as opposed to half a dozen.

 

It's okay. I agree that to some degree, a fish enthusiast freaking out about disoriented swimming makes them try too hard. But what gets me, is that I did absolutely nothing different from my normal routine. All I did was add nitrate reducer and CO2 booster. That was it.
I may have to agree with RedLoredAmazon, now that they mention it. I only had a vague idea of what the ammonia, nitrate, and pH levels were before I did the water change. I didn't think it would end up being so drastic. But thank you all for the kind condolences. Life goes on, I guess. I tried. I really did.

I want to add that I strongly suggest you buy some prime if anything other than to just make your life easier. One treatment as opposed to 3 for your new water has got to simplify things and harder to screw up. Again not saying that was a cause at all, but the product is highly recommended on this forum for good reason.

 

Can you list the specific products you used? All of them?
You said everything but the co2 was routine but what about the nitrate reducer in the new water and using ph down? Sometimes tinkering with the ph artificially can cause problems. Could it have caused a ph fluctuation or a side effect from the chemical?

I just feel like we have to look at this scientifically. Also the series of additives you use being routine doesn’t make it less relevant, there may be interactions or conflicts with a single additional chemical in play. Again I don’t know what those would be but I wouldn’t discard the possibility when trying to figure out this tragedy.

Well, the thing is, my fish started acting weird before I even put pH Down in there. I only did that to try to resolve the issue.
It could have been the nitrate reducer. However, I feel it wasn't even that much. Just enough to help out dead snail buildup. About 5 ml, for a 75 gallon tank. These are a list of the products I used in chronological order:

-Top Fin Ammonia Remover, 10 ml
-Top Fin Tap Water Dechlorinator, 10 ml
-Seachem Prime, 10 ml
-API CO2 Booster, 5 ml

Then the fish started acting funny. So I did:
-API pH Down, 10 ml

Hope that helps.

 

Well, the thing is, my fish started acting weird before I even put pH Down in there. I only did that to try to resolve the issue.
It could have been the nitrate reducer. However, I feel it wasn't even that much. Just enough to help out dead snail buildup. About 5 ml, for a 75 gallon tank. These are a list of the products I used in chronological order:

-Top Fin Ammonia Remover, 10 ml
-Top Fin Tap Water Dechlorinator, 10 ml
-Seachem Prime, 10 ml
-API CO2 Booster, 5 ml

Then the fish started acting funny. So I did:
-API pH Down, 10 ml

Hope that helps.

That helps a lot and I’m glad I asked! Again not attributing any cause, but you don’t need to use the top fin products at all if you are using prime.

 

API co2 booster contains glutaraldehyde. It is a biocide. Kills plants and animals slowly over time, and could kill a lot sooner if you overdose. Do not use. Not safe for humans as well.

 

I have heard of liquid co2 killing fish and plants because it's a lab created chemical or something, as stated above. but, others have used it without any ill effects. you just have to be absolutely sure not to overdose. typically you would only use it as an algaecide (such as flourish excel) instead of a co2 booster. it'd probably be best to rely on natural elements and actual co2.

that being said, it could have been any of the suggestions above or a combination of things that killed them. i've also heard about ph buffers being a bad thing. i'm sorry about your little dudes.

 

First, let me say I'm very sorry for your loss... I agree with the others...too many chemicals. Get rid of the Top Fin stuff and just use Prime. Make sure you are dosing the correct amount for the 75 gallon tank size. Was the new water temperature matched to the tank water? Don't mess with the pH. Let the fish adjust naturally. I've never tried to mess with mine. If the tank smelled bad it sounds like there was something going on. The dead snail, if left in the tank very long would have most likely caused an ammonia spike and a smell. If the filter smelled bad maybe the media needed rinsed in old tank water. That may also be why the filter wouldn't restart. I'm not an expert and have no idea what happened exactly but sounds like there was too much going on at one time for the fish to handle. Live plants are awesome for extra water filtration. If they are planted in sand they will require root tabs and you should also dose the tank with a liquid fertilizer at least weekly. Use a good all-in-one fertilizer so you don't have to mess with using separate bottles of individual elements. I use Thrive but I just started using it so I don't have an opinion about it right now. It's supposed to be really good.

 

First, let me say I'm very sorry for your loss... I agree with the others...too many chemicals. Get rid of the Top Fin stuff and just use Prime. Make sure you are dosing the correct amount for the 75 gallon tank size. Was the new water temperature matched to the tank water? Don't mess with the pH. Let the fish adjust naturally. I've never tried to mess with mine. If the tank smelled bad it sounds like there was something going on. The dead snail, if left in the tank very long would have most likely caused an ammonia spike and a smell. If the filter smelled bad maybe the media needed rinsed in old tank water. That may also be why the filter wouldn't restart. I'm not an expert and have no idea what happened exactly but sounds like there was too much going on at one time for the fish to handle. Live plants are awesome for extra water filtration. If they are planted in sand they will require root tabs and you should also dose the tank with a liquid fertilizer at least weekly. Use a good all-in-one fertilizer so you don't have to mess with using separate bottles of individual elements. I use Thrive but I just started using it so I don't have an opinion about it right now. It's supposed to be really good.

Yeah, I do use root tabs for my plants. They perked my plants right up over a month or so.

It also seems likely I could've been doing too much, like others have said. But if API CO2 Booster contains glutaraldehyde, and is harmful to fish and humans, I think I'll stay away from that product for now.

I don't think this'll hinder me from keeping fish in the future. I just don't think I'll be doing a planted aquarium for awhile. There's a lot of things that need to be balanced, especially for a rookie, like myself. If you sway too much on one end of the spectrum, it's over.

Good advice to just stick to one Seachem product. Seems logical and practical. Hope Thrive works out for you. I will start investing only in Seachem brand.

API co2 booster contains glutaraldehyde. It is a biocide. Kills plants and animals slowly over time, and could kill a lot sooner if you overdose. Do not use. Not safe for humans as well.

Well, shoot.
Now I feel bad for not knowing about that little detail.

 

Yeah, I do use root tabs for my plants. They perked my plants right up over a month or so.

It also seems likely I could've been doing too much, like others have said. But if API CO2 Booster contains glutaraldehyde, and is harmful to fish and humans, I think I'll stay away from that product from now.

I don't think this'll hinder me from keeping fish in the future. I just don't think I'll be doing a planted aquarium for awhile. There's a lot of things that need to be balanced, especially for a rookie, like myself. If you sway too much on one end of the spectrum, it's over.

Good advice to just stick to one Seachem product. Seems logical and practical. Hope Thrive works out for you. I will start investing only in Seachem brand.

Good luck with everything! I myself find planted tanks easier than non-planted tanks. I put plants in my very first tank with a betta. I was low light so I just used java fern. It grew huge with very little care. Helped water condition a lot. Right now I have a 4 month old tank that is struggling to grow my plants... can't figure out why...