New Neon Tetra breathing rapidly

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Aquarium Advice Apprentice
Jan 3, 2024
Just tried to post this and it didnt work so i will try again. In a brand new tank, about 5 days old, I have 8 neon tetras and 10 neocaridina shrimp. last night when I went to check on the before bed, the tetras were all breathing very fast, some were breathing at the very top of the tank, and one appeared to have lost his blue stripe, although that may just be how he was born and I didn't notice. The other tetras all have vibrant colors. The shrimp are doing fine. After some reasearch, it looks like it could be a problem with water parameters, a disease, of a problem with dissolved oxygen in the water. My parameters, are o nitrate and nitrite, 50-60 kh, ph of about 7. The one that is really high is the gh, which is at 150 or maybe even higher. For the oxygenation, i have a water coming from higher up that would splash into the tank. however about 2 days ago it start running along the wall and dripping in at the bottom instead of falling in, which could have led to an oxygen deficiency. i fixed the waterfall yesterday night. When I came to check on them this morning, they were all breathing fast but none were at the top breathing like yesterday. Im not sure if not enough oxygen has entered the tank or if thats not the problem. They show no signs of disease other than the one with little to no blue stripe but he's also the smallest one in the group so he could just be the runt. They could also be really stressed, but I dont know what from. Parameters have been steady and there have been no temperature changes. Update: just found one sitting on a rock that doesnt seem to be breathing. idk what the problem is and really need some help.
A lack of oxygenation will kill fish pretty fast. So it could be that.

There is a concern with your water parameters though. A cycled tank should have nitrate in it. You also arent reporting on ammonia, which is the most likely parameter to be off.

The parameters you are reporting on suggest you are using test strips. Test strips just arent reliable, so you cant trust any testing done with them.

So first up. Can you provide some more information?

What size tank do you have? What filtration does it have? How long has it been set up?

If the tank is new, did you cycle it before adding fish? If so, how did you cycle the tank?

What test kit are you using? Do you know your ammonia?

What is your normal water change routine? How much, how often? Did you do your testing before or after a water change?

So to sum up, it might be an oxygenation issue. If the water fall stopped operating for an extended period (say 10 to 12 hours), and your filtration provides no surface agitation to facilitate gas exchange, this could be the culprit.

But, unless you can provide some additional information, i would say your tank isnt cycled and its a water quality issue.
Thanks for responding aiken. Tank is 5 or 6 days old. have done one 15-20 percent water change. It is about 16-17 gallons total, but this is going to be a paludarium, so the back area will have a false bottom filled with leca(expanded clay balls) so about fifty percent of the tank actually holds fish. the only cycling I did was adding some water from an established tank that should have included beneficial bacteria. Now that i look back, this probably wasnt enough. I am using the test strips which arent super accurate. Is it possible to take it to a petstore to get the ammonia measured? also what is the best way to get rid of ammonia? just adding more beneficial bacteria? For the waterfall, it likely stopped operating for around 24 hours or maybe longer It has been back to operating for more than 12 hours and the fish are still gasping. What is the best approach from here?
Also, it looked like the fish that died lost a bit of its red color. Is there any chance this is a disease?
If its a disease, one fish dying isnt going to tell us anything. Even without disease not every fish is going to be healthy. Some will die no matter what you do.

You need to cycle the tank.

The microbes you are trying to grow doesnt live in the water, so adding water from an established tank is no help whatsoever. The microbes live on surfaces. Mostly this is your filter media, but it will also live on the substrate, the glass your aquarium is made of, any decorations etc.

The only thing you will have transferred with the water you used are any pathogens that may have been in the aquarium the water came from. Going forward, never put any water from another tank in your own tank. There are zero benefits, only potential problems.

You can get water tested at pet stores, but to cycle the tank you will need to be testing at least once a day, possibly for 2 or 3 months. So its better to get a good test kit, like the API Freshwater Master Test Kit so you can do your own testing rather than daily taking a sample to the store.

The only way to remove ammonia from an uncycled tank is water changes. 50% water change removes half the ammonia.

There are ways of cycling a tank before getting your fish, but unless you plan on returning everything we are past that. And cycling a tank with fish, you should start with 1small fish for every 10g of water. So 1 or 2 fish in your case. Again unless you plan on returning fish we are past that also. So cycling the tank, with so many fish and inverts is going to hard on them.

For now, until you can test for ammonia, change 50% of the water every day.

When you get your test, test every day for ammonia and nitrite. Add them together. If ammonia + nitrite combined is more than 0.5ppm change enough water to bring it below that 0.5ppm combined target. Once you are consistantly seeing zero ammonia and nitrite you are cycled enough for the fish you have and can add some more and continue the process until you are fully stocked. With all those fish and inverts in that size tank, expect to need to change water every day or 2 for a couple of weeks. The frequency of water changes needed should get longer as your cycle establishes, until you dont see any ammonia or nitrite and can then settle into a regular water change routine.

A good way to speed up this process would be to put a small amount of filter media from an established filter into your filter, or get a sponge from an established filter and squeeze it into your tank water. Perhaps you have a friend who keeps fish who could let you have some? This will seed your filter with the bacteria you are trying to grow and speed up the process.

Another option is bottled bacteria like Dr Tims One + Only or Tetra Safestart. These products wont instantly cycle a tank as they claim but in a similar manner to adding established filter media they can seed your filter with the bacteria you are trying to grow to establish your cycle. These products are hit and miss as to whether they work at all, but are an option if established filter media isnt obtainable and may speed up the process from several months to several weeks.
Thanks so much! The water from the tank was from the guy at the aquarium store. He said it would help. I dont have any other tanks so I guess ill go for the bottled bacteria. Thanks again!
Lesson learnt. Aquarium store people often know no more than you do. They are mostly just trying to earn a living.

They advised you poorly. They gave you terrible advice on cycing the tank and shouldnt have sold you so many fish to go in an uncycled tank. Dont listen to that guy again, he doesn't know what he's doing.
just got the tetra safe start and put it in. Will give an update tomorrow. Also thinking about adding some floating plants to suck extra ammonia and other stuff from the water while also making the shrimp and fish more comfortable with the shade. Is that a good idea?
Tetra safestart isnt going to make any immediate difference. At best it might reduce the time to cycle the tank from 3 or 4 months, to 6 or 7 weeks. Thats if it does anything at all.

Did you get a test kit?

Did you do the 50% water change?

Plants tend to either take up ammonia or nitrate. If its a plant that prefers ammonia it will help your water quality issue. If its a plant that absorbs nitrate then it wont, but will be beneficial once your tank establishes. My understanding is that true aquatic plants are nitrate absorbers, whereas terrestrial plants are ammonia absorbers, so things like pothos will consume ammonia. So it really depends on the plant. However, removing ammonia from the water will starve those microbes you are trying to grow, and set back your tank cycling. Not a problem as long as the plant stays there, but if you remove it sometime in the future you will be removing your aquariums ability to consume ammonia along with it because your tank wont have grown all those microbes. Swings and roundabouts. If you plan on keeping the plant long term then its a good idea. Be aware that floating plants are very nutrient hungry, so you might need to dose some fertilisers to keep them healthy.
Update: 2 tetras dead, one almost dead, 2 missing. I got the water testing kit and tested it. It looks like its between 0.25 and 0.50 ppm of ammonia, which is very high, although is it really bad enough to kill 5 fish in 1 day? from what ive seen im in the danger zone but not so bad that it will instantly kill fish. Maybe my tetras were already weak because they were fairly newly introduced? or maybe tetras in general are really temperamental. Im about to do the water change and well see what the ammonia is after that.
also, the one tetra that is likely going to die soon was still gasping at the top even though the waterfall has been functioning just fine. Im still not sure whats really goin on.
As explained you arent cycled. Your fish arent dying instantly, they have been living in their own waste for days since you introduced them. If your ammonia is around 0.5ppm now and you have done the water changes recommended it will have been at higher levels before the water changes. We really have no idea how high ammonia got before you did your water change and before you where able to test for it.

What you are seeing is common for new hobbyists, people start in the hobby with no understanding of the nitrogen cycle, expect to be able to throw some fish in a tank, periodically change some water, and everything will be good. Some get away with it for various reasons, some dont. Its no criticism of you to be in this situation, its caused by pet stores either not understanding the issues in new aquariums, or if they do know not informing new hobbyists of what they should be doing. Their job is to sell stuff though, which they've done.

As per my previous posts cycling a tank with fish you should be starting with 1 fish for every 10g of water so the parameters dont get too bad in short periods of time. I explained that with so many fish and inverts it will be hard on them, and what you are seeing is the result of this.

If any of the fish and inverts survive, things will get easier with lower bioload. But ammonia poisoning causes long term health issues. Your remaining fish/ inverts could survive the cycling process, but those health issues will be long lasting, and going forward they are going to be more prone to disease and probably wont live out their expected lifespans.

We cant rule out a pathogen, there is even a disease named after neon tetras. Fish live with diseases all the time, same as people do. If you live in an industrialised area with poor pollution control you will be more likely to have health issues and have shorter a lifespan. If fish live in clean water, are otherwise healthy and have a good immune systems then they fight off infection, if not those infections are more likely to kill the fish. But we do know your tank isnt cycled, we do know there is a water quality issue, and we do know that what you are seeing is consistent with poor water quality. You need to focus on what we know, not what other things might be going on.

Just to cover everything, what water conditioner are you using?
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I am using API pond water dechorinator and heavy metal neutralizer. There are currently 1 tetra and 5 shrimp left and ammonia levels have been consistently under 0.25 ppm for 2 or 3 days.
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