injured fin

Question
I noticed that my goldfish Bubbles has a reddish (bloody)
joint on one of her fins! Is that normal? Or just healing? It
doesn't have any red anywhere else.Please help!

-Tabitha

Answer
Hi Tabitha,
Little red streaks or 'veins' in goldfish fins is quite common and these appear due to several reasons.

They can be a cause for concern because sometimes these red streaks appear when the 'nitrates' are too high, meaning not enough water changes are being done on the tank and with goldfish as the big polluting fish that they are, this could be a highly possible reason bubbles is showing this in her fin.

Its definitely helpful to use simple test kits from your petstore to check the nitrate level and make sure your fish are in healthy water. Its also very helpful to have ammonia and nitrite tests as well. The test kit instructions will tell you what the tests mean and what to do about them if they are too high.

I would recommend a 30% water change and make sure to gravel vacuum too. Always insure the replacement water is equal in temp or just a tad bit warmer than your fish's water and always use water conditioner.

You should read here which describes some of the reasons why goldfish develop red streaks including some pictures as well.

http://thegab.org/Articles/DiagnosisChart.html#Streaks

Sometimes these red streaks show up on goldfish and they don't mean anything bad at all and its all simply due to the goldfish being a very light color.

Best of luck and I hope this helps!
Karen~