*Input Wanted* Investigating sudden deaths in aquarium fish.

[Guppy Guy]

Hi all. As you may have seen, I recently lost one of my favorite angelfish to an unknown cause. That wasn’t the first time it happened though, it was about the forth. I created this to try and figure out what it is, where it comes from, how to prevent it, and how to cure it. I want to hear all input and opinions, as well as any theories you may have. I will put my details below. Thanks for contributing everyone!(If you don’t want to read all this, only the 2nd and last paragraphs are vital)

The first memorable case I had was with a Dalmatian molly about a year ago. The second case was a guppy, and the third was a swordtail. All the victims were in perfect health and perfect water parameters to begin with. All had been in the tank for at least a year, though the angelfish and swordtail had been in it for 3 years. There were no obvious symptoms that slowly became noticeable as with most diseases. It was just “first day, perfect health, second day, almost dead, third day, dead” Every. Single. Time. Let me break that down. The first day, as mentioned above, the fish was perfectly fine. Acting normal, looked normal, and behaved normal. The second day, they just dropped. All the victims would kind of shimmy around for the first hour or so, and then drop to the bottom of the tank and sit there on their side. They all would try to swim around, but just didn’t have the strength to. The worst is on the third day though. In the morning, I would have already moved them to a hospital tank, medicated with various medications I will talk about later. They would try to eat the food I put in front of them, but don’t have the strength to swallow it. It truly is the most pitiful thing I’ve ever seen, and I hate re-seeing it every time a fish gets this. Then about midday, the fish improves. It can eat normally, acknowledge my presence, and almost swim upright. Then it suddenly dies out of nowhere. It also happened with every fish.

The medications I used all gave the same results as mentioned above. I tried plain aquarium salt, pravipro, marycen, pimafix and melafix, focus, metroplex, and stress coat. The water parameters were the same as the tank it came out of(temp 76F, ph 7.5) and I used a 1:3 ratio of new water to old tank water. I also put substrate in the tank to help cycle it, as well as established filter media and an extra air stone.

It is worth noting that all these fish were in the same tank, and that tank is still running today, as is this problem. The tank they all came out of is a used 36 gallon bow front, and when I get it, it had been empty for 15 years, so no cross-contamination. There is a bubbling ship decoration that came with the tank, and PVC pipes that add shelter and style to the tank(they look old since they are covered in algae). The substrate is a 2:3 ratio of sand to gravel. The light is a fluval aquasky 3.0, the heater is a Eheim jäger, the filter is a fluval 307, and the air pump is an aqueon quietflow(I think). I will list the fish, though know that not all of these were in here at once. The tank has always been reasonably stocked. The fish include 3 angels(now 2 😞), between 3 and 5 guppies(still there), a swordtail(one of the victims), a molly(first victim), a swordtail(victim), a whiptail catfish(still there), 4 zebra danios(still there), and snails(I try to remove them, but they always come back).

I don’t know if this is a common issue or not, or where to begin looking for it. If you have had similar experiences, please share. I am thinking it is some kind of bacterial infection, but I would like to know your theories as well. If I can come to some kind of conclusion, I will share and hopefully be able to update with good news. I will also be contacting local fish stores and interviewing many people, so I will post the results here. Thanks in advance for sharing! 

Edit: it is worth noting that I posted this more for research then help. 

Edited June 2, 2022 by Guppy Guy

[nabokovfan87]

What is your water change schedule, what % of water changes do you normally do?  How often do you clean the canister, gravel vac?

What is your feeding regiment and schedule?

[Guppy Guy]

I do water changes every 2-3 weeks, and clean the filter in the old water every time. I also gravel vac with every water change, which is usually a 30-45% depending on how dirty the tank is and how long its been since the last one.

I feed every morning around 10am. I only feed once daily. I feed flakes mostly but will feed frozen brine shrimp(cleaned and drained) a few times a week instead.

[nabokovfan87]

I think this is what's going on.

 

what is your PH?

 

Quote

Because all of this happens slowly, the fishes in the aquarium have time to adapt to the changes in the water chemistry. The weaker ones often die, but the stronger ones survive, although they are more susceptible to disease and will usually have shorter lifespans. Any newly added fish are likely to perish quickly, as they cannot adjust to the poor water chemistry.

 

[Guppy Guy]

I don’t know though. I mean, she had been in there for 3 years before it happened, as did all the fish that died from it. And the last water change I did was a 30% one only 2 weeks ago. Tuesdays water change was about a 60%water change, simply because I needed the old water for the quarantine tank. Also, I just added some guppies to the tank about 2 weeks ago, after the water change, and they all are as healthy as can be.

I try to keep the ph around 7.5, but it never falls below 7.0. I measured my tap water, and its ph is 7.0, so I do have to use a little alkaline buffer.

 

Edited June 2, 2022 by Guppy Guy

[gardenman]

The reality is that fish die. Mollies, guppies, and swordtails at three years old are getting up there a bit. Angelfish can live up to ten years, but how old was your angel when you got it? With the deaths coming over the course of a year, I don't see this being something infectious or even something all that unusual.  People can live to be over a hundred years old, but many die in their fifties and sixties. Some die in their teens and twenties.  Life expectancies are just best guesses. I don't see anything you're doing that's obviously wrong. The reality is fish die. If anything, you might be overmedicating them when they show signs of trouble. That's a lot of meds you've tried. Sometimes the meds do more harm than good. I wouldn't worry about things too much. Death happens.

[Brian]

I don’t think it’s “old tank syndrome” due to the regular aquarium maintenance schedule.  I have a couple aquariums up and running since 2001 - 2002.  Both have under gravel filters as well as HOB filters.  
Three years is a long time to keep a mollie, guppy,  swordtail and a lot of fish.  The angle fish should live 10ish years. I wonder how old it was when you purchased it.  
But, what you described doesn’t sound like a fish passing away because of age.  
I have to wonder if there was a very drastic environmental change (poisoning, water temperature) that may have caused this.  
A couple years ago, I noticed at a pet shop they had a tank with sudden deaths.  While talking with owner the pet shop mascot (a cat) used his litter  box and then jumped on top of the tank where he cupped his paw to catch water to get a drink.  Sometimes we need to think outside the (litter ) box.

[Guppy Guy]

On 6/2/2022 at 2:09 PM, Brian said:

I wonder how old it was when you purchased it.  

When I got her about 3 years ago, she was really small. Before I bought her, I talked with the store about her, and she was locally bred, and used to local water conditions. When I got her, she was about the size of a golf ball, and has since grown to be baseball sized. That tells me that she was no more then 5 years old, probably closer to 4.

On 6/2/2022 at 2:09 PM, Brian said:

I have to wonder if there was a very drastic environmental change (poisoning, water temperature) that may have caused this.  

There are no cats in my place, and I don’t use any air sprays or aerosols. The only thing I can think of is the vent that is above the problem tank, but it sucks air in. Not out. I have not had any problems with this vent in the past poisoning water or anything. There is a hood on top of the tank that has a pretty tight fit(as in 90% of the water surface is covered. The 10% remaining is for the filter/heater lines) and there is no dust or anything else on top of it. Also, if it were water quality, the other fish would show signs of it too. Over the years, I have learned how to see the slight difference of color in a fishes finbase, and that is how I know my ammonia and nitrite levels are off. Anytime the algae starts growing, I know it is time for a water change since the nitrates and/or phosphates are too high. Every time I test my water, my prediction is always extremely close to the result, so much so that I would have done the same things weather testing or not.

[nabokovfan87]

On 6/2/2022 at 11:09 AM, Brian said:

I don’t think it’s “old tank syndrome” due to the regular aquarium maintenance schedule.

You can develop OTS with a maintenance schedule in place. It happens.  There's ways to test it, but I would probably be changing water more often in this situation depending what parameters say.

 

On 6/2/2022 at 11:32 AM, Guppy Guy said:

Over the years, I have learned how to see the slight difference of color in a fishes finbase, and that is how I know my ammonia and nitrite levels are off. Anytime the algae starts growing, I know it is time for a water change since the nitrates and/or phosphates are too high.

 

[Guppy Guy]

On 6/2/2022 at 2:35 PM, nabokovfan87 said:

You can develop OTS with a maintenance schedule in place. It happens

Even if it is OTS, wouldn’t all the fish be affected? I fell like if it were anything to do with water quality, the more susceptible fish like the catfish or guppies(mine are sensitive to water quality. Hardy as usual to everything else though) would show signs first. My angelfish seem to be the hardiest in the tank since they are the last ones to show signs of problems when something happens.

[nabokovfan87]

No.  Even if you go to the store and have 10+ fish from the same source. There's going to be a portion of "weaker" fish.  Those usually won't be able to handle the parameter issues over time. I was trying to read up in it yesterday, I quoted the pertinent part I found regarding fish in the tank that would die off seemingly randomly.

It's a complex issue, but the easiest way to rule it out is to track PH, KH, GH, Nitrates.

 

Cory's video does a very good job of explaining the issue with not changing enough water, or not often enough. 

[Guppy Guy]

So the other day, I did the hardest thing I have done in my life. I cut open my angelfish that died to look for internal parasites and found this. I forgot to take a regular picture, but I did get one from under my microscope. It is attached below.

Inside her were probably 50 or so small(<2mm) black lines so to speak that may or may not have been parasites. I don’t know what these are, so opinions are welcome. It took me a few days to post this, because like I said, it was extremely difficult. 

[JessLynne7]

On 6/4/2022 at 12:08 PM, Guppy Guy said:

So the other day, I did the hardest thing I have done in my life. I cut open my angelfish that died to look for internal parasites and found this. I forgot to take a regular picture, but I did get one from under my microscope. It is attached below.

Inside her were probably 50 or so small(<2mm) black lines so to speak that may or may not have been parasites. I don’t know what these are, so opinions are welcome. It took me a few days to post this, because like I said, it was extremely difficult. 

Dr bassler does a lot on fish diseases. You may have to dig deeper online to abets ect that do these types of articles. Your brave but you have a lot of info. Some scientist out there will need and want this info

[nabokovfan87]

Very sorry for your loss @Guppy Guy.  I hope someone is able to help and this brings you some solace.

[Guppy Guy]

Ok, so today, the 2 other angelfish decided to spawn out of nowhere. Could this have anything to do with what happened to the other one?

I also took the eggs out of the tank to try and artificially hatch them, but now the other two are “fighting”(one lunges toward another, either stops short or gently nudges). Is this normal?

Edited June 8, 2022 by Guppy Guy