Injured or sick yellow goldfish

[Manuel 0]

Hi, looking for some help for my yellow goldfish... A sore on its side appeared today, there appears to be a couple of scales missing, a pink mark of about 3mm in diameter, the surrounding scales are discoloured black, any ideas if it is an injury or something more sinister? It's in a 42 gallon tank with 3 other goldfish and 4 zebra danios, 25% water changes every 2 weeks using rainwater. 

https://www.dropbox.com/s/uj6gc3gjohasaun/Yellow.jpeg?dl=0

Edited March 29, 2017 by Manuel
Unable to attach photo

[FishyMandy 6,260]

Hi, Welcome to Kokos! It would help a lot if you could fill out this form, it will help the mods to assess all areas that could cause issues and figure out the exact problem. If you have trouble copying and pasting it, you can quote my post and fill in your answers there. You may also find our guidelines helpful - 

Test Results for the Following: * Ammonia Level(Tank) * Nitrite Level(Tank) * Nitrate level(Tank) * Ammonia Level(Tap) * Nitrite Level(Tap) * Nitrate level(Tap) * Ph Level, Tank (If possible, KH, GH and chloramines) * Ph Level, Tap (If possible, KH, GH and chloramines) Other Required Info: * Brand of test-kit used and whether strips or drops? * Water temperature? * Tank size (how many gals.) and how long has it been running? * What is the name and "size of the filter"(s)? * How often do you change the water and how much?

* How many days ago was the last water change and how much did you change? * How many fish in the tank and their size? * What kind of water additives or conditioners? * What do you feed your fish and how often? * Any new fish added to the tank? * Any medications added to the tank? * List entire medication/treatment history for fish and tank.Please include salt, Prazi, PP, etc and the approximate time and duration of treatment. * Any unusual findings on the fish such as "grains of salt," bloody streaks, frayed fins or fungus? * Any unusual behavior like staying at the bottom, not eating, etc.?

[Manuel 0]

Test Results for the Following: * Ammonia Level(Tank)  no testing done * Nitrite Level(Tank) * Nitrate level(Tank) * Ammonia Level(Tap) * Nitrite Level(Tap) * Nitrate level(Tap) * Ph Level, Tank (If possible, KH, GH and chloramines) * Ph Level, Tap (If possible, KH, GH and chloramines) Other Required Info: * Brand of test-kit used and whether strips or drops? * Water temperature? room temp about 25oC * Tank size (how many gals.) and how long has it been running? 42 gallons, 1 year * What is the name and "size of the filter"(s)? Aquaone AR-850 tank with filters in the lid * How often do you change the water and how much? every 2 weeks, 25%

* How many days ago was the last water change and how much did you change? 5 * How many fish in the tank and their size? 4, approx 12cm * What kind of water additives or conditioners? none * What do you feed your fish and how often? granules and flakes twice a day, occasionally peas  * Any new fish added to the tank? no * Any medications added to the tank? no * List entire medication/treatment history for fish and tank.Please include salt, Prazi, PP, etc and the approximate time and duration of treatment. none * Any unusual findings on the fish such as "grains of salt," bloody streaks, frayed fins or fungus? none other than the sore mentioned * Any unusual behavior like staying at the bottom, not eating, etc.? none

[shakaho 6,312]

Welcome to Kokos!

Thank you for filling out the form. Now, please read our guidelines as Mandy requested.  You will see that your tank is small for four goldfish, and also that you can make up for low water volume by changing more water.  With twice the ideal number of fish, you should double the minimum recommendation of changing 50% of the water weekly.  Whether you should do two 50% changes weekly or one very large change weekly depends a lot on the difference between the tank and tap  nitrate and pH readings.  If possible, please get a test kit and provide the parameters.  In the US, fish and pet stores will usually do free water tests for you.  I don't know if they do that in Australia, but you can ask.

You have a beautiful yellow hibuna, and he looks healthy.   The black around the edge of the wound indicates healing tissue, so the injury probably happened at least two days ago.  The only treatment for a scrape like this is very clean water.  For greatest safety, you can move the injured fish to a "hospital tank/tub" and change the water daily until the wound has completely healed.  A plastic storage box with a capacity of ~10 gallons costs little and works well.  You might speed the healing by adding salt to a concentration of 0.3% to the hospital tank as described here.

If you don't want to remove the fish from his current tank, please do 50% water changes daily for three days to lower the bacterial count in the tank and thus decrease the probability of infection.

I'm curious about the age of your fish.  You said the tank has been running for a year.  Did you get them then as babies?

Edited March 29, 2017 by shakaho

[fantailfan1 26,742]

Gorgeous fish.  I'd love to see the others when you get a chance/once your fish is healed up.

 

Welcome to Kokos.  You've gotten excellent advice.

[Manuel 0]

Thank you very much for your advice shakaho, I'm relieved it's an injury and not a disease, I've done a 50% water change today and will repeat over the next few days the fish is looking fine at the moment.  We bought this fish about 6 months ago, it was about 5cm long at the time of purchase.  Sounds like we will have to look at getting them a bigger home as they grow, thanks again for the help.

And thanks fantailfan1

[shakaho 6,312]

Excellent!  As long as the fish looks and acts fine and the wound doesn't look inflamed, he has avoided infection.  We need to figure out how he injured himself.  Could you show us some full tank shots so we can look for hazards?  Also, we want to see all of those fish!

This fish has shown rapid growth, and if the others have done so also, you will want that bigger tank in about a year.  

Three things affect the tank size you need: pollution, gas exchange, and swimming space.   You can handle pollution with water changes.  You can maintain the same water quality with twice as many fish as we recommend by doubling the water changes.  The effectiveness of gas exchange depends on the surface area since that is where oxygen gets absorbed and carbon dioxide escapes, but also on the depth of the water since the gases have to diffuse from the surface to the bottom of the tank and from the bottom to the surface.  Thus, we recommend a tank with the largest surface area (footprint) and the least height that you can find and fit into your room.  

I'll explain swimming space later.  I have to tend to my fish now.