Help!!!! my fish are dying

[Jayztar]

Hi Everyone,

I setup an brand new tank a month ago (its been stocked for a month, it has been running longer as I did a fishless cycle). It had x9 Pepper Corys, x9 Odessa barbs, x14 zebra danios and x6 giant danios. Since setting it up and stocking it I have had six deaths, x2 corys, x2 barbs and x2 giant danios. The first barb died after I found him stuck between the filter intake and the glass of the aquarium. He was badly injured and so I euthanized him.
The first cory died the very next day after I got them, so I assumed he was already sick (He was missing his barbells) and so I replaced him and watched the others to make sure they were okay.
Another cory followed a few days later (he had his barbells) he started acting funny like he couldn't swim well and was breathing very rapidly (Note water parameters at every death was 0 for ammonia, nitrate and nitrite).
About a week later I lost a Giant Danio I found him dead stuck on the intake of the filter. He had been swimming funny (like he was off balance) and I thought he had dropsy. I thought that the filter intake could be to strong as I had seen fish get pulled towards it as they tried to swim past. So I put some foam around it to lessen the suction. Which has worked as I have seen the fish swim happily around it now.
The next day I found another Giant danio stuck between the foam and the glass. He was alive but died by the end of the day. He looked okay but was swimming funny and breathing kinda fast (I assumed injury from being stuck).
The next day I noticed an Odessa barb looked sick (fins drooping and very dull) he was not really swimming like he would swim a bit and then start sinking and then he'd sink down onto some plants before trying to swim again etc. I put him in a floating guppy breeder tank inside the main tank to isolate him (I don't have a hospital tank) I went to the pet store and bought blue planet multi cure which treats common diseases such as white spot and velvet disease and fungal infections ( I thought maybe they had a fungal infection). I dosed the tank and the next day the Odessa had died. The Odessa died yesterday and today I noticed another sick Giant Danio. Once again he seems to have lost the ability to swim. He swims a bit and then starts to sink. He is kinda on an angle too, like his head is upwards and his tail is pointing down instead of being horizontal. I have put him in the isolation tank but I don't think he is going to survive. He seems to have given up on swimming at all now and is just lying on the bottom.

I don't know why they're dying!!!! I thought the other fish (the earlier fish deaths) were filter accidents but now I'm not sure. Please, any help would be much appreciated!!!!

Maybe its a parasite??

Just a reminder all the Ammonia, Nitrate and Nitrite test are always coming back as 0 ( I also brought new tests incase my old tests were too old and weren't showing the correct results).

More info I have had the zebras in the longest and they're fine, the odessas went in a week later, the giants about three days after that and then the corys a week later.

Sorry for the long post

 

[Jayztar]

Update the Giant Danio is now lying on his side on the bottom of the isolation tank (guppy breeder tank). He is thrashing around like he is tying to swim but can't!!!!

My tank is 250 L that helps

 

[fluttermoth]

This sounds awful, how upsetting for you; I hope we can help..

I don't want to sound like I'm patronising you, but are you sure you're doing your tests properly? It's incredibly rare, so much so as to unheard of in reality, that tanks run with zero nitrate. As it's produced by the final step of the nitrogen cycle, if your tank was cycled it should be showing some nitrate. What's the level in your tap water? What test kits are you using? What ppm of ammonia did you cycle to?

Do you know the hardness and pH of your local water? What temperature are you running the tank at? What decor/plants do you have?

 

[Jayztar]

The water is quite soft in my area 38 mg/L (CaCO3). My pH is around 7-7.4 colour is between the two on the colour indicator sheet. The temperature is 21C. I know that it is unusual to show 0 nitrite but I have not seen any colour change using the API water tests. I have previously been using the aquaone water tests for nitrate and ammonia but I replaced them with new API water tests ( I haven't replaced the Nitrite test it is still a couple years old).
I have been very careful to put in the correct number of drops, shake them carefully to mix and then wait fifteen minutes as per the instructions.

I have a really good filter which I why I assumed the water was very clean (its a aqua one 2700 external canister) so the whole tank gets turned over 10.8 times an hour.

 

[Jayztar]

The Giant Died I have attached some photos of both him dead and one I took of him alive resting on the bottom of the breeder tank.

 

[Essjay]

I'm sorry to hear about your fish problems

Re the tests, are you leaving the API tests 15 minutes before reading? They are supposed to be read after 5 minutes.
And are you shaking nitrate bottle #2 as the instructions say, and also the test tube before starting the timer? Not doing the shaking is the most common cause of false nitrate readings. One of the reagents settles out on the bottom of the bottle and the shaking is necessary to get it back into the liquid.

 

[Jayztar]

I have done my tests again and they are still reading the same, I set a 5min timer on my ph to be sure. Its reading 0 for nitrite, between 0 and 0.25 for ammonia (there is a light green tint to the yellow colour but it hasn't changed colour) I get the exact same colour for my tap water.
The colour doesn't change from yellow for the nitrate and yes I do shake the indicator 2 bottle (I shake them all just incase before I use them but I shake the 2 nitrate bottle a lot more).
I always rinse the test tubes with tap water, then I rinse them with aquarium water before I run the tests.
I also have been doing frequent water changes. I started with twice a week while adding the fish but moved to once a week. The Odessa died right after a water change, so if it was a water quality issue he should have died before or a few days after???

 

[Jayztar]

Oh and the décor of the tank is its a fairly heavily planted tank with water wisteria and ambulia, amazon sword, hair grass, java fern and anubias. I dose with Flourish excel but way less then the instructions say and I have seachem root tabs in the substrate which is mostly sand but some of the tank has the flourish shrimp and plant substrate. And there is golden vine drift wood that I got from a pet store.
Could the root tabs hurt my fish if I used to many?

 

[Jayztar]

I took a sample of my water to my LFS and they said that it had 0 Nitrate, Nitrite and Ammonia, so my test readings must be correct. They suggested that I add salt to harden the water and increase the temperature. The owner of the store has a display tank with Odessa barbs and they keep the tank at 25C

I hope it works as I lost another Cory cat this morning after a water change

 

[Essjay]

If the shop meant plain ordinary salt, that won't harden the water. Hardness refers to the amount of divalent metal ions in the water - this is mainly calcium with some magnesium and trace amounts of other metal ions. Salt is sodium chloride, and sodium is a monovalent metal ion so it won't 'harden' the water.
And the fish you have won't like salt (sodium chloride) in their water.

However, if they meant remineralisation salts of the kind use to remineralise RO water, that would raise the hardness. These products are a mixture of the minerals found naturally in water. If you use these salts, you would need a GH test kit so that you would know how hard you were making the water, and you would have to add exactly the same amount per litre to the new water at every water change.

Since the fish you have are soft water fish, the tank hardness does not need raising by much, if at all.

 

[Jayztar]

If the shop meant plain ordinary salt, that won't harden the water. Hardness refers to the amount of divalent metal ions in the water - this is mainly calcium with some magnesium and trace amounts of other metal ions. Salt is sodium chloride, and sodium is a monovalent metal ion so it won't 'harden' the water.
And the fish you have won't like salt (sodium chloride) in their water.

However, if they meant remineralisation salts of the kind use to remineralise RO water, that would raise the hardness. These products are a mixture of the minerals found naturally in water. If you use these salts, you would need a GH test kit so that you would know how hard you were making the water, and you would have to add exactly the same amount per litre to the new water at every water change.

Since the fish you have are soft water fish, the tank hardness does not need raising by much, if at all.

The mixture I bought from my LFS is remineralisation salts not salt salt (i.e sodium chloride) I believe the mixture is calcium carbonate mostly. I did buy the API GH and KH water test kit my GH is still very low less then 50ppm but my KH is now closer to 100 ppm (it was only 50ppm before). I have noticed a very positive change in my tank since raising the temperature and water hardness, everyone looks colourful and are swimming around happily so fingers crossed. The water parameters of my tank now match those of the LFS where I got them from.

 

[Hoopla]

Oh and the décor of the tank is its a fairly heavily planted tank with water wisteria and ambulia, amazon sword, hair grass, java fern and anubias. I dose with Flourish excel but way less then the instructions say and I have seachem root tabs in the substrate which is mostly sand but some of the tank has the flourish shrimp and plant substrate. And there is golden vine drift wood that I got from a pet store.
Could the root tabs hurt my fish if I used to many?

I'm a total newbie when it come so to fish but I used to dose with excel (tiny amounts) but I stopped after hearing from a member on here that excel is really bad for the fish. Maybe that could be your problem?