A fantail fins turning black is quite common and may or may not be cause for alarm. It’s important to note any changes in behavior and eating habits of the goldfish that are happening at the same time.
It might be caused by one of these 4 issues that can be easily rectified.
1. Ammonia Burns
2. Goldfish naturally change color
3. The tank is too small
4. Water temperature
If water is not properly filtered and cleaned, the toxins can cause burns to the goldfish that cause the fin to turn black.
It is distressing to see the fin of your goldfish turning black, but it’s not always as serious as it appears. But the combination of major changes in normal habits along with changing color are signs there could be a serious problem.
In most cases the black color is a sign the healing process has already begun, and further treatment isn’t necessary.
Causes of your goldfish fins turning black
#1 Ammonia Burns
This is the most common reason and is a result of the tank not being properly cleaned. Food that’s not eaten and fish waste causes toxins to build in the water.
If the water isn’t properly filtered and cleaned often, the toxins can cause burns to the goldfish. The black color is a sign the infection is healing, and cleaning out the tank properly will help ensure the infection doesn’t return. In time, the goldfish should return to normal color.
#2 Goldfish can naturally change color
It’s possible that there’s nothing wrong at all. Goldfish are known to change colors. The change could be just a normal process for the fish.
#3 The tank or aquarium is too small
The tank isn’t large enough for the number of goldfish. People often begin with a small tank or bowl when buying their first fish. The water very quickly gets stagnant if it’s not cleaned regularly. Toxins then infect the tank and cause illness.
#4 Water temperature
It’s hard to keep the water temperature regulated in a small bowl. The small size of the tank easily warms and causes infections in goldfish and you’ll find your fantails fin turning black.
Simply investing in a larger tank minimizes this problem.
Purchasing a 10 or 20 gallon tank for your fish is generally sufficient to ensure the goldfish has plenty of room to swim. The size recommended depends of course on the number of fish living in the tank.
It’s also easier to install a filter system to a larger tank.
If the fish is acting normally, the water is clean, and the water temperature is fine, there’s probably no reason for concern.
If you’re still worried it’s best to completely clean out the tank because keeping a clean fish tank is the ideal way to avoid diseases and unnecessary infections.
We have three goldfish and a painted turtle in our 30 gallon aquarium. The turtle is about six inches in diameter and the largest goldfish is about one pound. We changed the water the other day, as it was starting to turn that lovely green colour. But, shortly after adding the required chemicals of chlorine remover and such; we noticed that it looked like our big goldfish started to act as though he is now blind and the smaller of the three has now got black on the tips of his fins and a black patch under his right eye.
Can goldfish go blind? and could the black spots on the fins be a result of the old water in the aquarium, having too much ammonia??
Is there anything that can be done to help the fish that might now be blind ??
Thank you any and all help that can be passed on.
Always follow the directions and ratio quantities when adding water conditioners to your aquarium. I’ve added a link that might be helpful https://howtotakecareofgoldfish.com/goldfish-problems-dealing-with-potential-problems for your goldfish. Here’s a reference link also for painted turtle care. http://www.reptilesmagazine.com/Care-Sheets/Turtles-Tortoises/Painted-Turtle/
all the best