My rainbow sharks are sick

[Denisa]

Hello good people! Please help!

I have two rainbow sharks that since I bought them they have not been very active besides when the smaller one is chased by the bigger one around the tank. Recently I had a finrot incident and yesterday when I have done the second treatment they where acting strange. Both were “dancing” with each other. After an hour of doing this so called dance I have noticed some white patches on the bigger one around the tail and back. Today they are back at being themselves, “hiding” in opposite corners of the tank. I have no idea if the smaller one took a bite at the bigger one ( as it looked like the smaller one was “leading the dance”), if it’s some fungus infection or something else.

 

[Aiken Drum]

Please take a read through the "unhealthy fish" sticky and give as much detail as you are able.

https://www.aquariumadvice.com/forums/f17/before-posting-about-unhealthy-fish-read-this-32451.html

I'd particularly be interested in your tank size. These fish get quite big and are territorial. A single rainbow shark would want at least 50g and to keep 2 or 3 sharks double that. Ideally if you are keeping multiple fish 4 or 5 fish are better in an even bigger tank so that aggression isnt constantly directed at a single fish and they can cohabit more peacefully.

 

[Denisa]

Sorry, I never been on a forum before. I didn’t know I had to answer all this questions. I will do my best at answering them.

I am new to the fish keeping community, only had the tank for almost an year. The tank and everything in it has been bought at the same time almost an year ago.

The fish type that is affected by some type of disease is rainbow sharks (to be honest the shop sold them as red-tailed sharks but they have all the fins red not just the tail). Both of them are around 15cm, I just called one bigger and one smaller not because of the length but one is fatter and one slimmer.
Only the fatter one is affected by this white patches.

I use to have a problem with the nitrite but now is good. The tank parameters are not perfect. Ammonia 0, nitrites 0.25, nitrates 5.0, pH is somewhere between 7.5 and 8, carbonate hardness >= 7dKH, general hardness ~15dGH. General hardness is the worst but I just don’t know what to do. As I said not perfect.

The tank is 110 litre ( 80cm X 35cm X 50 cm). The filter that I have is a EasyCF2 cartridge system ( not in at the moment because of the finrot treatment), a twin bar tri-colour RGB LED lighting system, an aquatropic submersible heater set at 24C and an air sponge filter.

I have two rainbow sharks around 15 cm, two pearl gourami 10 cm, 5 cardinal tetra 5 cm and a couple of guppy various sizes only have 4 that are full size ( I would like to say 15 as they are breading like crazy, I started with 4), and a giant African shrimp. All the fishes have been bought at the same time not counting the babies that the guppy had, as I said I bought only 4 at the start.

I do water changes and vacuum and clean the tank every two weeks( 70% water change). A week ago I have done the “deep clean” this week I had done a 30% water change to repeat the finrot treatment.

I feed the fish Aquarian complete nutrition tropical & temperate flake food, tetra micro granules complete food for small tropical fish and tetra crusta menu for the shrimp.

Everything is the same since I have bought the tank and later the fishes, including the water treatments for water changes. The new-ish thing in the tank is the air sponge filter that I bought 3 months ago.

Hopefully I have answered everything.

 

[Aiken Drum]

White patches does seem to indicate a fungal or bacterial issue.

As to cause those are 2 full grown sharks in too small a tank. You mention aggression between them and that is likely to continue as they are now adult and dont have enough space to keep out of each others way. Stress and aggression are key causes of illness in fish. Even if you heal your fish up, you arent removing the cause.

If you cant provide a much bigger home i would consider rehoming the sharks. Even taking one out, the tank is too small and the aggression could then be directed towards your other fish.

As to treatment i would look at moving the affected fish to a quarantine tank. Keeping the water pristine with plenty of water changes and a stess free environment will help no end. Treating with aquarium salt and/ or broad spectrum medication will also help.