sideways floating angel fish

Question
Hi, Karen. We have an angel fish (we think it a female) that has for the past several weeks been floating either on her side or upside down.  We kept her in a tank with other fish, two being angels and we think males.  The female (we will call it that for identifcation purposes) started floating on it's side or upside down.  We had one fish that appeared to be munching on this females gills so we removed her to a tank of her own.  She is still floating.  While we noticed that the red inside her gills seems to be less in intensity, she is still floating sideways.  However we noticed that she appears to have side buldges or interior bubbles causing the sides to buldge. This has been going on for weeks. We thought she was dying but she is still hanging on-sideways.
Any suggestions?  We are at a loss
Thanks.

Answer
Hi Roz, it sounds like your little angelfish has a swim bladder disorder. The swim bladder is a sac that runs in the fishes middle and is responsible for maintaining balance in the fish. Sometimes causes like bacterial infections can disrupt the swim bladder and render her unable to maintain her equalibrium. But the most common causes of this (and this disorder is common in many fish), is diet. If you feed dry foods and she eagerly eats them, this is almost certainly causing her buoyancy problems. When dry food (flakes or pellets), hit the water, eagerly gobbling fish (like angels) eat up the flakes or pellets as soon as they hit the water, filling themselves up. But what happens now is the dry food absorbs water inside the fish and expands, disrupting the swim bladder and usually causing the bloating you are seeing. The poor fish have problems from floating on his/her side, upside down, or sometimes even being unable to get up from the bottom. I have seen this happen with Bettas and goldfish but it can happen to just about any fish. Certain fish seem to be more prone than others, all fish are individuals anyway.
Treatment for swim bladder disorder relating to diet includes feeding her frozen green peas, be sure to thaw them out completely, shell them and mash them up. You may have to hand feed her with a blunt toothpick before you can get her totally well. Peas are well known to dislodge blockages in the swim bladder and if fed several times a day in moderate amounts, might even cure her in a short while. You should also be sure and fast (not feed) her for several days but continue with the green pea preparations. She needs to clear her system out and fortunately most fish love eating green peas.

Always insure to maintain good water quality with partial water changes to prevent any bacterial disease resulting from dirty water.
The green pea feedings and several days of fasting from any dry foods should help her get completely better. Don't give up on her whatever you do. She has a 99% chance of recovering and I don't suspect her problem to be bacterial.

After she recovers always presoak her dry food well enough for it to expand fully before feeding it to her. Not all fish require this and as I said, some may be more prone, all fish are individuals...

If you have anymore questions, feel free to email me...

I wish you and your Angelfish the best! Hope she gets well!

~Happy holidays and Happy fishkeeping!~
Karen~