Help with identifying why fish died in new tank

[ctpan]

Hi,
Looking for some advice/insight into what caused fish death.
I have a 29 gallon freshwater tank about 12 days old. After setting it up I added fish flakes for 2 days and bottled bacteria hoping to kick start cycling. About 2 days in water got cloudy then cleared up a little in a week. Tested with strips and 0 ammonia, nitrite, nitrates and ph 6.4. Did not do a water change.

Picked up 3 skirt tetras. Fish store suggested adding aquarium salt so added 6 tablespoons prior to introducing fish. After adding fish, they swam erratically. One was listless and had clamped fins, another swam up and down the glass with it's nose. 3 hours later one was lying at the bottom with labored breathing. The other would flip 360. Soon both died.
Unsure what to do at this point I made a 30% water change. The 3rd on seemed to do better. Swam more and fins slightly more fanned out. Unfortunately it was dead in the morning.

Bought API master test next day and got 0 ammonia, nitrite, nitrates and ph 7.8. Took water sample to fish store and they got the same numbers.
Owner said ph is too high and that's why they died. They keep their tanks at neutral. Suggested drift wood, which I have sitting in the tank now.

Tested my tap water after letting it sit for 24 hours and it was 7.6.
Since then I have done another 30% water change to remove the remaining rotting fish flakes. Tested again and got 0 ammonia, nitrite, nitrates and ph 7.6.

From what I have read skirt tetras will tolerate ph of 7.6/7.8. Researching this is it possible that:
1. Bacteria bloom and added salt reduced oxygen levels to an unsafe level?
2. Water quality was toxic from rotting fish food being in the tank for over a week?
3. PH too high?

Are there other tests that I should do that might give a clue as to the cause?

Scared to get more fish until I figure out what happened.

 

[10 Tanks]

Hello. A 29 gallon tank is pretty small. When I cycle a tank, I fill it and allow it to sit for a couple of days to steady the water temperature. Then, I add some bacteria starter and a few hardy fish. As soon as I add the fish, I change half the water a couple of times a week for a month or so and continue to add the bacteria starter when I change the water. After the month, I gradually add fish and extend the water changes to half every week. I never allow the tank to go longer than a week without changing half the water. My guess is, the water wasn't changed often enough. Small tanks require large water changes a couple of times a week.

10 Tanks (Now 11)

 

[FishKeeper72]

To be honest, I think it was the salt... I bet it was a lot of shock for those fish to go from pet store water to your water with lots of salt In it. Maybe try to just put fish in the water without salt. Usually salt is for treating diseases or doing weekly or monthly separate soaks to help boost the immune system. That's the only reason that makes sense of why they died. Especially how your water levels were perfect.
Did you acclimate them properly?

 

[10 Tanks]

Hello again. Unless you add a lot more salt than the standard one tablespoon for every five gallons of replacement water, the fish shouldn't have died. One tablespoon of salt in five gallons of water will barely show up in a water test.

10 Tanks (Now 11)

 

[ctpan]

To be honest, I think it was the salt... I bet it was a lot of shock for those fish to go from pet store water to your water with lots of salt In it. Maybe try to just put fish in the water without salt. Usually salt is for treating diseases or doing weekly or monthly separate soaks to help boost the immune system. That's the only reason that makes sense of why they died. Especially how your water levels were perfect.
Did you acclimate them properly?

Yes, floated the bag for 30 mins, then poked some holes and let it sit for another 15 mins. Even though the water levels looked ok I wonder if there was something else that was toxic which I did not test for.

 

[ctpan]

Hello again. Unless you add a lot more salt than the standard one tablespoon for every five gallons of replacement water, the fish shouldn't have died. One tablespoon of salt in five gallons of water will barely show up in a water test.

10 Tanks (Now 11)

I added 6 tablespoons directly into the tank prior to adding fish so it matches the standard dose you mentioned.

 

[Byron]

A few observations.

First...there is no need to add salt to a freshwater fish aquarium, unless there is a specific disease issue and then only if salt is the safest and effective for that problem. I am not saying the salt alone killed the fish, but it certainly did not help things because these fish come from freshwater which has no measurable salt per say. Salt is detrimental to freshwater fish, very much so.

When you do need to add salt for a disease problem, you must dissolve the salt completely in water and then pour that in the the aquarium. I am reading that you just added the salt on its own, and if so, this can burn fish. There is nothing to indicate salt is needed here anyway, but keep this in mind should you have to use it down the road.

Second, the pH...a pH in the 7's will not harm this species, but I am curious about the pH of 6.4 and the increase to 7.8, this increase in a short period of time is dangerous, highly so, to fish. What is the pH of the tap water on its own? Remember you need to out-gas any CO2 when testing tap water pH, so let a glass of fresh water sit for 24 hours. Or find the pH level from the water authority assuming you are on city water and not a private well.

The advice from the fish store is basically wrong all round. Do not acquire any more fish until this issue is resolved. And think twice about this fish species, it needs a group of 10-12 or more, and it gets a decent size, and it is a feisty species that is prone to fin nip. It cannot be kept safely with sedate fish. You might want to rethink getting this species in the future.

Do you have any live plants? What product did you use for the nitrifying bacteria?

Last suggestion for the moment...when fish are in trouble the first action is usually a major water change, 70-80%, using a good conditioner and no other substances/additives. Take out a bit of the existing water before the water change so you can perform the tests on it.

 

[ctpan]

A few observations.

First...there is no need to add salt to a freshwater fish aquarium, unless there is a specific disease issue and then only if salt is the safest and effective for that problem. I am not saying the salt alone killed the fish, but it certainly did not help things because these fish come from freshwater which has no measurable salt per say. Salt is detrimental to freshwater fish, very much so.

When you do need to add salt for a disease problem, you must dissolve the salt completely in water and then pour that in the the aquarium. I am reading that you just added the salt on its own, and if so, this can burn fish. There is nothing to indicate salt is needed here anyway, but keep this in mind should you have to use it down the road.

Second, the pH...a pH in the 7's will not harm this species, but I am curious about the pH of 6.4 and the increase to 7.8, this increase in a short period of time is dangerous, highly so, to fish. What is the pH of the tap water on its own? Remember you need to out-gas any CO2 when testing tap water pH, so let a glass of fresh water sit for 24 hours. Or find the pH level from the water authority assuming you are on city water and not a private well.

The advice from the fish store is basically wrong all round. Do not acquire any more fish until this issue is resolved. And think twice about this fish species, it needs a group of 10-12 or more, and it gets a decent size, and it is a feisty species that is prone to fin nip. It cannot be kept safely with sedate fish. You might want to rethink getting this species in the future.

Do you have any live plants? What product did you use for the nitrifying bacteria?

Last suggestion for the moment...when fish are in trouble the first action is usually a major water change, 70-80%, using a good conditioner and no other substances/additives. Take out a bit of the existing water before the water change so you can perform the tests on it.

I added the salt direct and waited for it to dissolve before adding the fish. Not sure if that makes a difference.
The ph of 6.4 was done with a test strip (before I got fish), then I got the API master test kit (after I got fish) after I was told strips are not accurate.
The ph of tap after letting it sit for 24 hrs is 7.6. Checked the city water site and they also say 7.6.
No live plants and I used API quickstart when first setting up the tank and then seachem stability after the fish was added.
For conditioner I use tetra aquasafe.

No plans on more fish until I have a better understanding of what happened. I've only done 2 30% water changes so far, should I do a 70% to get rid of whatever was causing the problem?

 

[Naughts]

floated the bag for 30 mins, then poked some holes and let it sit for another 15 mins.

Just float for 10-15 minutes to equalise the temperature, then net the fish out and add them to the tank without any bag water.
Prolonging the transfer means they sit in a tiny quantity of water for longer which can expose them to toxic ammonia and nitrite. Fish cannot acclimate to other parameters in minutes or hours, it takes at least weeks and, in some circumstances, never.

after I was told strips are not accurate.

IMO test strips are reasonably accurate but others will disagree. The biggest downside is if they do not show an ammonia reading.

 

[Byron]

I agree with Naughts above. The fish are all dead now, but one or more water changes won't hurt anything. Though I would want to be more certain of the issue(s) before adding any fish here. Do you have live plants? These greatly help in "cycling" by taking up ammonia, especially fast growers like floating or stem plants. The QuickStart and the Stability do not contain the specific nitrifying bacteria to help cycle so don't get more. The only good cycling products are Tetra's SafeStart and Dr. Tim's One and Only. The latter invovles actual cycling with his ammonia product, while the SafeStart can be added if fish are present.

The pH seems to be 7.6 which is fine, but the drop to 6.4 needs to be determined. What is the GH and KH of the tap water? These are connected to pH.

 

[10 Tanks]

Hello again. Salt is fine in a fish tank, especially in the early cycling period. For one, it helps the fish deal with a little higher nitrogen level that you typically have in the cycling process. But, if you keep up with an aggressive water change routine and dose the bacteria starter when you change the water, the nitrogen from the fish waste will be next to none.

10 Tanks (Now 11)

 

[ctpan]

I agree with Naughts above. The fish are all dead now, but one or more water changes won't hurt anything. Though I would want to be more certain of the issue(s) before adding any fish here. Do you have live plants? These greatly help in "cycling" by taking up ammonia, especially fast growers like floating or stem plants. The QuickStart and the Stability do not contain the specific nitrifying bacteria to help cycle so don't get more. The only good cycling products are Tetra's SafeStart and Dr. Tim's One and Only. The latter invovles actual cycling with his ammonia product, while the SafeStart can be added if fish are present.

The pH seems to be 7.6 which is fine, but the drop to 6.4 needs to be determined. What is the GH and KH of the tap water? These are connected to pH.

Using test strips, the ph was at a constant 6.4 the first 12 days before I got fish. After introducing fish and them dying in 5 hours the next day I got API master kit. Using that gave a reading of 7.6. Tested it 2x in the last 4 days and all were 7.6. Testing with the strip now gives 6.4 again. GH is 25 and KH is 0 for tap water. Chlorine is also 0 which seems suspicious.

Thanks for the advice on safestart. Should I use it now or wait until I am ready to get fish?

 

[Naughts]

Use the regular API pH test kit. The high pH test kit's lowest reading is 7.6.

 

[Byron]

Agree with Naughts again, use the regular pH not the high, they will give different readings often but the one which includes the actual pH is the relevant test. The 6.4 is making more sense now we have the GH and KH. Anyway, the API is agreeing with the water authority so use the regular from now on.

GH at 25 presumably ppm or mg/l (same) is good for soft water fish species. The KH is 0 so no buffering. My tanks for over 30 years ran with 0 KH and a GH of 7 ppm and an acidic pH. These numbers will mean the pH does drop, probably what occurred before. Not a problem with soft water fish. The parameters will stabilize over the first few months, keep water changes weekly with 50% or more.

Would not worry about the chlorine test, assuming you use a conditioner. Do they add chlorine or chloramine?

On the SafeStart, follow the directions. I have never used this, I have never "cycled" an aquarium in my 30 years because I always have floating plants and they take up incredible amounts of ammonium/ammonia. With an acidic pH it is primarily harmless ammonium as well. And nitrite is not a by-product of plants using ammonium, and thus less nitrate too. Win-win all round with plants.

 

[ctpan]

Agree with Naughts again, use the regular pH not the high, they will give different readings often but the one which includes the actual pH is the relevant test. The 6.4 is making more sense now we have the GH and KH. Anyway, the API is agreeing with the water authority so use the regular from now on.

GH at 25 presumably ppm or mg/l (same) is good for soft water fish species. The KH is 0 so no buffering. My tanks for over 30 years ran with 0 KH and a GH of 7 ppm and an acidic pH. These numbers will mean the pH does drop, probably what occurred before. Not a problem with soft water fish. The parameters will stabilize over the first few months, keep water changes weekly with 50% or more.

Would not worry about the chlorine test, assuming you use a conditioner. Do they add chlorine or chloramine?

On the SafeStart, follow the directions. I have never used this, I have never "cycled" an aquarium in my 30 years because I always have floating plants and they take up incredible amounts of ammonium/ammonia. With an acidic pH it is primarily harmless ammonium as well. And nitrite is not a by-product of plants using ammonium, and thus less nitrate too. Win-win all round with plants.

Yes, I use a conditioner, tetra aquasafe. From the town's water report they test for chlorine but did not see a test for chloramine.
Correction, the town's water report say tested ph is 7.9 (from 2 years ago).