Fish Keep Getting Sick and Dying

[Fishcake1]

Hello All,

I’m new to the fish keeping hobby. I’ve had my fist 10 gallon tank since April. I tried to do as much research as possible on stocking and supplies as I could. The tank has a heater (for 20 gallon), 1 sponge filter with an air stone (for 20 gallon), 1 hang on the back filter (Tidal 35), and some temperature gauges.

Currently stocked in the tank there is 1 betta fish, 3 ember tetras, and 2 nerite snails. I used to have 7 ember tetras but 1 by 1 they keep getting sick and dying. About once a month 1 fish suddenly gets sick and then passes away. The fish always look very healthy and are eating well. Then suddenly one day I notice 1 fish is moving it’s mouth a little bit more than normal; still swimming and eating normally (not gasping for air at the top at all). A few hours later the fish has lost all color and passes away.

My water parameters are always good (7-7.2 ph, 0 ammonia, 0 nitrite, and about 5 ppm of nitrate). The temperature is always between 78-80 F. I’ve tried different medications thinking it could be a number of different things but it didn’t help. I’ve done water changes just in case when I start to notice a fish not doing so well with dechlorinated water at the same temperature as the water in the tank.

The tank is heavily planted so there are a ton of hiding places for the fish if needed. From what I have witnessed there is no chasing between the betta or the tetras so I can’t imagine it to be stress.

I don’t know what I’m doing wrong and I’ve tried looking up what this could be. Everything I look up says either my water parameters aren’t right or there isn’t enough oxygenation in the tank. But my parameters, when I test, are always good and I have a sponge filter with an air stone so I don’t know how much more oxygenation I would need.

The weird thing is that it’s only 1 fish at a time this happens to every month and at that time all the other fish look good and healthy. If someone could help me figure out what I’m doing wrong that would be amazing.

 

[itiwhetu]

Simply you have a bad mix Bettas and Ember Tetras won't work. The little Tetras will just get stressed out and then die. Betta's need to be kept by themselves or in very large tanks with other fish

 

[Colin_T]

Need paragraphs in the post so I can follow what has been written, and pictures and video of the fish.

You can upload videos to YouTube, then copy & paste the link here.

If you use a mobile phone to film the fish, hold the phone horizontally so the footage fills the entire screen.

 

[CaptainBarnicles]

Betta are solitary fish, they are very territorial and need their own space.

It would be useful to know your water hardness to check the fish you have are even suitable for your area, something I had no idea about when I first started out!

 

[CarissaT]

Ditto. Tetras usually like water with a low KH and GH. In addition to your nitrogen tests (which you are doing very well to have gotten) you can also get a GH (general hardness) kit which will tell you how much calcium and magnesium you have in your water. As well, KH measures the level of carbonates. If you have these on the higher end, you are probably better off going with something other than tetras, for instance livebearers like platies or swordtails would be better suited.

Medication is generally not advised unless you know for sure what you’re treating. It creates additional stress to the fish and can mess with your good bacteria, usually it does more harm than good.

I had a similar experience where occasionally a fish would just languish and die and I couldn’t pin it on anything. Finally in the end I figured out I had high copper levels in the water (my water was soft and going through copper pipes, picking up the copper). But if your snails are good, that’s not the issue, because they would have died first.

And sometimes I think you basically get a bad batch of fish. I’ve had neons before that would just drop off one by one, and others that all survived for over 2 years. I‘m not an expert on fish diseases, but sometimes I think they either have a disease from the get go or they were stressed too much and weakened at some point and just lose their ability to thrive and fend off disease.

The number one thing you can do which you are already aware of is water changes, a 50% - 70% water change a week with gravel vac is what’s recommended. If you have chlorine in your water make sure to dose enough dechlorinator for the whole tank at each change. To me your oxygenation sounds fine, with a filter plus a sponge filter you should have plenty.

 

[AdoraBelle Dearheart]

Hi, I suspect that it's the stress/potentially attacks from the betta, which are likely to happen when you're not watching, or you've bought Embers from a not great source, and it's a sickly bunch. Possibly a combination of both these things. A betta with ember tetra can sometimes work out for people, but sometimes it doesn't - so it may be a learning experience that this betta needs to solitary, and perhaps a chance to get another tank to have a community tank, and get that MTS going

Mainly I wanted to say that I'm really impressed, it's clear that you've done a lot of research, have been doing a lot of reading here I think! And followed a lot of the advice people here give when there's a potential problem. Just want you to know that it's clear that you care about them and want to give them the best possible care, and you're prepared to read, research and put work into it! There's a steep learning curve when you first join the hobby, and I went through a similar problem with guppies when I first began keeping fish myself. Was doing everything I could to try to make sure the tank was perfect, water testing perfectly, lots of live plants etc, and was so frustrated, trying to figure out what I was doing wrong, while feeling like a fish murderer!

But your instincts are good and you're doing the right things.

I tried to do as much research as possible on stocking and supplies as I could. The tank has a heater (for 20 gallon), 1 sponge filter with an air stone (for 20 gallon), 1 hang on the back filter (Tidal 35), and some temperature gauges.

All of this is a great start, especially for someone new to the hobby.

Currently stocked in the tank there is 1 betta fish, 3 ember tetras, and 2 nerite snails. I used to have 7 ember tetras but 1 by 1 they keep getting sick and dying. About once a month 1 fish suddenly gets sick and then passes away. The fish always look very healthy and are eating well. Then suddenly one day I notice 1 fish is moving it’s mouth a little bit more than normal; still swimming and eating normally (not gasping for air at the top at all). A few hours later the fish has lost all color and passes away.

The spaced out nature of the losses (I'm sorry for your losses ) makes me suspect that it's stress from living with the betta, the betta bullying overnight, or possibly weak stock that just isn't thriving. Where did you get them from?

I’ve tried different medications thinking it could be a number of different things but it didn’t help.

Oops, that's a commonly made mistake. Understandable when losing fish to panic and want to throw meds at the issue as a last ditch effort, but it nearly always causes more harm than good. Resist the urge to run to products or meds when you don't know what you're treating, since any med, even the right med treating the right thing, puts fish through stress. Even the right med treating the right thing, when combined with the problem and any other stressors the fish have, is enough to push a fish over the edge and kill it. But when it's necessary, you have to use the right med for the right thing, and try to minimise stress for the fish to give them the best chance of fighting off any illness.

So throwing in random medications without knowing what you're trying to treat usually just makes things much worse. Just becomes a chemical soup that can crash your cycle and interact with each other badly, or a useless product sold just to make money.
Clean fresh water is the best first aid, so water changes while seeking more info about your specific problem, not meds or products unless and until you have to, and you know what med you need.

I’ve done water changes just in case when I start to notice a fish not doing so well with dechlorinated water at the same temperature as the water in the tank.

Great water parameters and that you have a testing kit and test. Potentially if there are swings in the parameters, which is common is a tank that is cycled, but not yet established, that can cause some underlying stress... those numbers are good, but you could do extra tests at different times of day and different intervals between water changes to see if any numbers are swinging between water changes. Doing a large water change when you see a problem or lose a fish, and making sure water is declorinated and temperature matched is exactly right though, so kudos for reading and following advice from folks like @Colin_T

The tank is heavily planted so there are a ton of hiding places for the fish if needed. From what I have witnessed there is no chasing between the betta or the tetras so I can’t imagine it to be stress.

The fish release hormones and pheromones into the water that we cannot test for, and sometimes bullying happens at night, or dawn and dusk when we're less likely to be sitting and watching the fish. Sometimes just knowing you're living with a predatory and potentially aggressive fish you can't escape is a low lying stressor, even if the betta is an angel and never looks at them.

I don’t know what I’m doing wrong and I’ve tried looking up what this could be. Everything I look up says either my water parameters aren’t right or there isn’t enough oxygenation in the tank. But my parameters, when I test, are always good and I have a sponge filter with an air stone so I don’t know how much more oxygenation I would need.

Deep breaths, at that temp and with an airstone and HOB filter, it's not a shortage of oxygen. You're doing well, even though you're experiencing losses. I know it might not feel that way right now, but you really are doing well and it's not necessarily something you're doing wrong. It might be less than ideal stocking that you'll learn from and improve, or it could be bad luck and sickly, poorly bred embers.

The weird thing is that it’s only 1 fish at a time this happens to every month and at that time all the other fish look good and healthy. If someone could help me figure out what I’m doing wrong that would be amazing.

 

[Fishcake1]

Ditto. Tetras usually like water with a low KH and GH. In addition to your nitrogen tests (which you are doing very well to have gotten) you can also get a GH (general hardness) kit which will tell you how much calcium and magnesium you have in your water. As well, KH measures the level of carbonates. If you have these on the higher end, you are probably better off going with something other than tetras, for instance livebearers like platies or swordtails would be better suited.

Medication is generally not advised unless you know for sure what you’re treating. It creates additional stress to the fish and can mess with your good bacteria, usually it does more harm than good.

I had a similar experience where occasionally a fish would just languish and die and I couldn’t pin it on anything. Finally in the end I figured out I had high copper levels in the water (my water was soft and going through copper pipes, picking up the copper). But if your snails are good, that’s not the issue, because they would have died first.

And sometimes I think you basically get a bad batch of fish. I’ve had neons before that would just drop off one by one, and others that all survived for over 2 years. I‘m not an expert on fish diseases, but sometimes I think they either have a disease from the get go or they were stressed too much and weakened at some point and just lose their ability to thrive and fend off disease.

The number one thing you can do which you are already aware of is water changes, a 50% - 70% water change a week with gravel vac is what’s recommended. If you have chlorine in your water make sure to dose enough dechlorinator for the whole tank at each change. To me your oxygenation sounds fine, with a filter plus a sponge filter you should have plenty.

Hello CarissaT,

Thank you for your reply! I’m buying a kH and gH kit to test to see if that could also be part of the problem. My snails are doing great so I don’t think it could be an issue with copper but my water could potentially be hard water but I’ll figure it out when I test.

I do weekly maintenance on the tank with gravel vac and 50% water changes. I also, as you said, make sure to add the water dechlorinator (enough for the tank).

 

[Fishcake1]

Hi, I suspect that it's the stress/potentially attacks from the betta, which are likely to happen when you're not watching, or you've bought Embers from a not great source, and it's a sickly bunch. Possibly a combination of both these things. A betta with ember tetra can sometimes work out for people, but sometimes it doesn't - so it may be a learning experience that this betta needs to solitary, and perhaps a chance to get another tank to have a community tank, and get that MTS going

Mainly I wanted to say that I'm really impressed, it's clear that you've done a lot of research, have been doing a lot of reading here I think! And followed a lot of the advice people here give when there's a potential problem. Just want you to know that it's clear that you care about them and want to give them the best possible care, and you're prepared to read, research and put work into it! There's a steep learning curve when you first join the hobby, and I went through a similar problem with guppies when I first began keeping fish myself. Was doing everything I could to try to make sure the tank was perfect, water testing perfectly, lots of live plants etc, and was so frustrated, trying to figure out what I was doing wrong, while feeling like a fish murderer!

But your instincts are good and you're doing the right things.


All of this is a great start, especially for someone new to the hobby.

The spaced out nature of the losses (I'm sorry for your losses ) makes me suspect that it's stress from living with the betta, the betta bullying overnight, or possibly weak stock that just isn't thriving. Where did you get them from?


Oops, that's a commonly made mistake. Understandable when losing fish to panic and want to throw meds at the issue as a last ditch effort, but it nearly always causes more harm than good. Resist the urge to run to products or meds when you don't know what you're treating, since any med, even the right med treating the right thing, puts fish through stress. Even the right med treating the right thing, when combined with the problem and any other stressors the fish have, is enough to push a fish over the edge and kill it. But when it's necessary, you have to use the right med for the right thing, and try to minimise stress for the fish to give them the best chance of fighting off any illness.

So throwing in random medications without knowing what you're trying to treat usually just makes things much worse. Just becomes a chemical soup that can crash your cycle and interact with each other badly, or a useless product sold just to make money.
Clean fresh water is the best first aid, so water changes while seeking more info about your specific problem, not meds or products unless and until you have to, and you know what med you need.

Great water parameters and that you have a testing kit and test. Potentially if there are swings in the parameters, which is common is a tank that is cycled, but not yet established, that can cause some underlying stress... those numbers are good, but you could do extra tests at different times of day and different intervals between water changes to see if any numbers are swinging between water changes. Doing a large water change when you see a problem or lose a fish, and making sure water is declorinated and temperature matched is exactly right though, so kudos for reading and following advice from folks like @Colin_T

The fish release hormones and pheromones into the water that we cannot test for, and sometimes bullying happens at night, or dawn and dusk when we're less likely to be sitting and watching the fish. Sometimes just knowing you're living with a predatory and potentially aggressive fish you can't escape is a low lying stressor, even if the betta is an angel and never looks at them.

Deep breaths, at that temp and with an airstone and HOB filter, it's not a shortage of oxygen. You're doing well, even though you're experiencing losses. I know it might not feel that way right now, but you really are doing well and it's not necessarily something you're doing wrong. It might be less than ideal stocking that you'll learn from and improve, or it could be bad luck and sickly, poorly bred embers.

Hello AdoraBelle,

Thank you for your detailed reply!

To be honest I knew it was a risk to put a betta fish in a tank with others but I was only aware of physical aggression being an issue (chasing etc). But after observing the betta with the others for a long time and the tetras or the betta not showing any signs of stress I thought it would work out. The ember tetras were always very calm and curious. They would break apart from their school and just explore the tank which I thought was a sign of happiness and confidence. However, I had no idea they also can omit pheromones that could intimidate the other fish without showing any observable physical signs of aggression.

I definitely want to get a community tank one day but I thought I should start out on the smaller side to get used to things first then move up. Maybe that will happen sooner than expected lol.

Do you think I should surrender the 3 ember tetras I have or should I try to invest in a larger community tank and put them in there with other things while the betta gets the 10 gallon to himself?

I got the ember tetras from a specialty fish store in my area that seems reputable and good. They’ve been open for a very long time and the people working there seems to know their stuff and we’re also hobbyists for many years. Maybe I got a bad batch that they just weren’t aware it was bad (I don’t really know)…

Thank you for validating my feelings and care for the fish! To be honest, I was feeling disheartened and was racking my brain on what I was doing wrong. The feeling of guilt that I’m not doing good enough is a very rough thing to feel. I feel better knowing I’m not the only one this has happened to.

 

[Byron]

Hello CarissaT,

Thank you for your reply! I’m buying a kH and gH kit to test to see if that could also be part of the problem. My snails are doing great so I don’t think it could be an issue with copper but my water could potentially be hard water but I’ll figure it out when I test.

I do weekly maintenance on the tank with gravel vac and 50% water changes. I also, as you said, make sure to add the water dechlorinator (enough for the tank).

Before buying a test kit you made only use the once, see if this info (GH especially, and KH or Alkalinity) is posted on the website of your municipal water authority (assuming you are on city water, not a private well). See what they give for the pH while you're there.

 

[Naughts]

I thought I should start out on the smaller side to get used to things first then move up. Maybe that will happen sooner than expected lol.

Do you think I should surrender the 3 ember tetras I have or should I try to invest in a larger community tank and put them in there with other things while the betta gets the 10 gallon to himself?

Actually, larger tanks are easier to maintain and keep balanced. If you can get a bigger tank for the embers (and compatible, peaceful tankmates once they are settled and doing well), I think this will be the best outcome.
If you surrender the embers they may not thrive anyway, especially with an additional move and rehoming adding to their stress.