What is killing my rainbow fish.

[Colgan10]

Have you tested your water?

Yes

If I did not test my water...

1. ...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.

Do you do water changes?

Yes

What percentage of water do you change?

91-100%

How frequently do you change your water?

Every week

If I do not change my water...

1. ...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.

Been trying to figure out what has been killing my rainbow fish happened about three months ago some not all have been getting sores on there sides. Sometimes it looks like a white thing is sticking out of it. I’ve treated with general cure, melafix, started Fritz bacteria. Any idea what this could be. The tank is 180 gallons is on my automatic water changes system it gets a 30 min water change everyday water levels are all good

 

[kno4te]

Hard to make out with the pics. Some close up pics in a net with light will help. Would dab the area with some methylene blue and try a salt bath 4 tsp in 1 g of water.

 

[Milingu]

Looks like a bacterial infection.
Once some of my fish got really badly infected with Aeromonas veronii. I had brought some fish from my pond back to my fish room.
It started with white pimple-like bumps (like something is sticking out) and turned quickly into open wounds like in your pictures.
I showed two fish to a vet who took a smear sample and sent it to a lab. 3 days later I got the required antibiotics from the vet. I could at least save half of the fish. Still a very devastating blow since multiple tanks got infected.

Lowering the temperature can be helpful to slow down the growth rate of the bacteria.

 

[Ansorgii]

Lowering the temperature can be helpful to slow down the growth rate of the bacteria.

I am sorry for interrupting this threat with my own issue, but I struggle with mouthrot and some unknown cause killing my fish away, would lowering the temperature be advised for that aswell? I am just to used to highering the temp for every health issue.

At the moment I have it on 30°C due to white spots returning a week ago.

 

[duanes]

Are your rainbows Chilatherina alleni? or ?
If so, they are often found in fast flowing streams, with comparatively cool waters, mid to low 70s F

Many of the Australian rainbows are also quite comfortable at those lower temps.
so as Milingu mentioned a slight cool down may be worth a try, especially because the disease appears bacterial,
and many bacteria get more virulent at higher temps.