fish with clear bubbles on him

Question
Hi my blood fin has bubbles that are clear all over him.  He seems pretty swollen.  He is still eating well and swimming around but I am concerned.  Could you help.  He is about 1.5"  in a 10 gallon tank.  The tank has been set up for 2 years.  There are 4 other small fish in the tank.  I change the water once a month.  

Answer
Hi Katrina;

It sounds like he could be swollen from fluid buildup, also known as "dropsy". It could be caused by organ failure, internal infection or any number of things. Since it's impossible to tell what the true cause is, we usually try antibiotics first. Since he is eating, an antibiotic food might work. Most fish stores carry them in the flake form. It would be best to isolate him to use it though. Fish that aren't sick should not have it. You could use an aquarium divider or one of those little breeder nets just during feeding time.

Make a water change of 25% too. It will help his immune system. Do it every week and vacuum the gravel at the same time. Once a month is really a long time to wait between changes. Nitrates will build up as the final result of your biological filtration and the only way to get them out is with water changes. When nitrates build up they can lead to these kinds of illnesses.

There are other things to try for dropsy too. Here are some links;

http://www.aquamaniacs.net/forum/cms_view_article.php?aid=128

http://badmanstropicalfish.com/articles/article24.html

I hope he feels better soon...

At Your Service;
Chris Robbins