Black tetras with unknown disease

[SonOfOrion]

Hello all,

I have 7 black tetras and I have been battling a disease for a while. I had a fish for about a month ago from this disease and I thought it was no longer in the tank however it has come back. Discolored splotches form on the fish and the fish will begin to bloat and become weaker at swimming. Some weird black tumors also form at the rear of the fish, I am unsure if this is related. This disease does appear to have affected multiple fish. I am hoping someone has encountered this before or has some insight. 

pH 6-6.5

Nitrite 0ppm

nitrate 20-30ppm

phosphate 1.5ppm

kH 0

GH 30

temp 83 degrees F

[nabokovfan87]

@Chick-In-Of-TheSea do you think this is what you dealt with on your tetras?

[nabokovfan87]

On 7/11/2023 at 9:55 PM, SonOfOrion said:

pH 6-6.5

Nitrite 0ppm

nitrate 20-30ppm

phosphate 1.5ppm

kH 0

GH 30

temp 83 degrees F

Hello, Welcome to the forums!

First note, I think your PH may be too low (you have no KH) as well as your temperature being very high for this fish.  I would encourage you to drop the temp to the 76-78 range over the next couple of days.  Heat adds stress and that can make diseases pop up and cause issues.

Here is an article explaining about the KH - PH relationship.
https://www.aquariumcoop.com/blogs/aquarium/ph-gh-kh

Here is an article explaining about the use of aquarium salt for treatment:
https://www.aquariumcoop.com/blogs/aquarium/aquarium-salt-for-sick-fish

I would suggest starting with the following steps in addition to the above adjustments.
-Try to use a KH buffer or crushed coral to boost up your KH, to get your PH to be more stable over time. (preferably 6.5-7.0 range)
-Add in some catappa leaves to help with any fungal issues and encourage some anti-bacterial and anti-fungal properties to the water.
-Add in aquarium salt to help with overall fish health and any external parasite (or protozoan) issues that you might be seeing.  The black sections on the body could be indicative of this.  (Normal dose is usually around 1/3-Cup per 10G of aquarium water)
-Add in erythromycin (Fritz calls this Maracyn) to help start bacterial treatment.
-Add in Ich-X to help with any external parasites and/or fungal issues you may see.

Once you have those going, you would follow the directions on the Erythromycin box for the sake of when to time your water changes.  You would do 30% of the tank volume each time you change water.  When you do your water change you would dose in the Erythromycin and Ich-X as directed.

Once we see how the fish respond to the first week under these conditions we will have a better idea of what you're dealing with.

[SonOfOrion]

Sounds great, I will start those suggested treatments and provide an update. Thank you!

[Chick-In-Of-TheSea]

On 7/12/2023 at 3:08 AM, nabokovfan87 said:

@Chick-In-Of-TheSea do you think this is what you dealt with on your tetras?

No, I was dealing with columnaris, but 1) columnaris is a quick killer, and 2) no bloating occurs.  The photos do not looks like columnaris at all.  The issue mentioned here is something else. The Fritz disease chart points to dropsy or internal infection, but I'm not sure as I have not personally dealt with that. Let's ask  @Colu

 

Note: the last line of this chart is cropped off. It suggest meds, but I am not vouching for those meds. They are all Fritz products and I think in some cases there are better meds to try and/or have had more positive results. It's case by case basis, really.

Edited July 12, 2023 by Chick-In-Of-TheSea

[Colu]

Looking at the pictures it looks like tissue damage that could be caused by a number of things bacterial infections viral infections parasitic infections coupled with the bloating I would be leaning towards a parastic infection with possible secondary bacterial infections are these black patches what your referring to as tumors as they don't look like typical tumors I have seen @SonOfOrion

Edited July 13, 2023 by Colu

[SonOfOrion]

If you look at the peduncle, the stem or pinch point of the tail, you can see a black mass. That’s the tumor I was mentioning. I figured the black patches along the body were part of some infection. I really appreciate everyone’s insight. 

@Colu

[Chick-In-Of-TheSea]

On 7/12/2023 at 12:55 AM, SonOfOrion said:

pH 6-6.5

Nitrite 0ppm

nitrate 20-30ppm

phosphate 1.5ppm

kH 0

GH 30

temp 83 degrees F

Had you taken an ammonia reading? Black patches are sometimes caused by ammonia burn. It can happen even if a tank is cycled. Sometimes something disrupts a cycle.

Edited July 13, 2023 by Chick-In-Of-TheSea

[SonOfOrion]

On 7/12/2023 at 5:05 PM, Chick-In-Of-TheSea said:

Had you taken an ammonia reading? Black patches are sometimes caused by ammonia burn. It can happen even if a tank is cycled. Sometimes something disrupts a cycle.

Interesting, I haven’t actually thought of that. I have not taken an ammonia reading. I should get a test kit within the next day. I’ll check that out as well