Here is a longer writeup:
I have a Oscar fish who has gotten pretty bloated as of the last month. He behaves normally, eats normally, etc. Today he was very sluggish, but ate normally yesterday. Fasting did not result in bloating going away, tried this for 4 days without food, then a week at 30% feedings, and then 70% feedings. Bloat has gotten far worse since last week, which is the time when I returned to 70% feedings. However he had that size of a meal for years without problems, and I really doubt it's considered a large feeding by any means.
I have seen some poops which I believe belongs to him. I also see something hanging out of his bum, but not sure what it is. I do not see it moving. Attached picture of it, and his bloat.
He has a good diet, with quality food (Hikari and Ocean Nutrition mainly). Frozen foods once per week as of late, as suggested by another forum. Also tried feeding peas every now and then, but have not tested epsom salts (in food nor bath), as was suggested against it.
120 gallon tank with frequent waterchanges and good filtration. He is about 6-7 years old.
His body looks normal, but it looks like he has swallowed a golfball. Just like a large bump on either side of his lower stomach. Slightly more on one side than the other. What can this be?
Tank
What is the water volume of the tank? 500l
How long has the tank been running? 7 years
Does it have a filter? Yes, plenty of filtration. 10x volume per hour, 2 large external canister filters.
Does it have a heater? Yes.
What is the water temperature? 25.5C.
What is the entire stocking of this tank? (Please list all fish and inverts.)
Oscar
Sailfin Pleco
2x Albino pleco
2x Common pleco
2x L333 pleco
4x Yoyo loaches
Unknown amount of baby pleco
Maintenance
How often do you change the water? Weekly (Every 7 days usually, sometimes 9-10 days on rare occasions)
How much of the water do you change? 35-50%
What do you use to treat your water? Nothing. Virtually chlorine free water, straight from tap, with temperature to match tank. Been able to keep fish and shrimp with great success this way for a decade.
Do you vacuum the substrate or just the water? Usually gravel vac parts of the tank
*Parameters - Very Important
Did you cycle your tank before adding fish? Yes
What do you use to test the water? Liquid test kit
What are your parameters? We need to know the exact numbers, not just “fine” or “safe”.
Ammonia: 0
Nitrite: 0
Nitrate: 10-20 (BEFORE waterchange)
pH: 7.6-7.8
Feeding
How often do you feed your fish? 6 days a week, one meal per day.
How much do you feed your fish? Quite little. A hungry fish is a healthy fish.
What brand of food do you feed your fish? Hikari, Ocean Nutrition, Tetra. Mostly Hikari/ON. 10+ different pellets mixed up.
Do you feed frozen? Not really/very rarely. Once per week as of late.
Do you feed freeze-dried foods? Not really/very rarely.
Illness & Symptoms
How long have you had this fish? 6 years
How long ago did you first notice these symptoms? 4 weeks ago
In a few words, can you explain the symptoms? Bloated. On both sides, slightly more on one side. Behaves normally other than this, perhaps a little sluggish but eats and swims normally.
Have you started any treatment for the illness? No food for 4 days. 1/3 meals for 4 days. Then 2/3 meals for 1 week.
Was your fish physically ill or injured upon purchase? No.
How has its behavior and appearance changed, if at all? Worse bloat as of late.
He is also behaving completely normally now, moving gravel and fake plant around; begging for food, etc.
