Why did Jack Dempsy die?

[Butter Cup]

My daughter has had a Jack Dempsy for four or five years. We kept him in a ten gallon cube aquarium and fed him frozen blood worms. We fed him three or four large pelets about every other day and he seemed quite happy and healthy. There were no other fish in the tank. I was just looking at him two days ago when I fed him and thinking how pretty he was and how his colors had developed. He also had his own personality. He seemed robust. Then, the next day I looked at him and he was lying on his side in the bottom of the tank. The food was the same we had been feeding him, so I am sure it was not spoiled. He did not have fungus or any visable signs of illness on his body and he had been growing. I know that no one can tell me why he died without looking at him or the tank, but I am wondering if anyone can give me a suggestion of what might have gone wrong. I know it wasn't old age, because I have read that these fish live eight to ten years and just read a post from someone who has had one for fourteen years. Were we not feeding him properly (he was growing) or is it possible that he needed more space? We thought he was a wonderful fish and would consider getting another Dempsy, but don't want to make the same mistake, if we can help it.

[kc5gvn]

Hello Butter Cup, First let me welcome you to Auspet. Without knowing what your water parameters are (ammonia, nitrite and nitrate) it is impossible t o tell what all of the contributing factors are. You are asking the right questions though. Since he was growing I don't really think that food was an issue. Unfortunately a ten gallon tank is much too small for a Jack Dempsey, even for just one. When fully grown they reach 8 to 10 inches in length. I would recommend 30 gallons, minimum, to allow them swimming room. Also a 10 gallon tank is much too small with regard to bacterial filtration. It would be almost impossible to keep the bacterial filtrataion (ammonia, nitrite and nitrate) stabilized. With a Dempsey that age in a ten gallon I would GUESS the nitrAtes to be well over 100, even with the tank being kept in immaculate shape. Nitrates should be maintained as close to 20 (or lower) as possible. Pet shops continually tell people that the fish they are buying will fit in a 10 gallon aquarium when the truth is that when they are full grown they will require something much larger. The key question to ask the pet store is "How big will this fish get when it's full grown?" Even better would be to research the fish before you buy it. Many times the person selling you the fish has no idea how big they get when full grown.

[Butter Cup]

Wow. Thank you. That is very helpful. Believe it or not, the fish was given to my daughter as a pet and was originally in a five gallon tank.