My Goldfish recently died...

Question
My goldfish, fluffy died a few days ago. I'm not sure why. My other fish, a Pink Gourami, kept biting it. After about 3 or 4 days, Fluffy started acting strange. He wouldn't swim or eat. I got a bowl and i scooped out water from the tank and fluffy and put it in a seperate bowl. Fluffy had really little red dots on his side. When he was in the bowl, he layed on the bottom, trying to breathe. It was really sad, but i am probably gonna get another one soon. After about 20 minutes later , Fluffy died. Now in my 10 gal. aquarium I only have a Black Sucker, Pink Gourami, Tiger Gear, and a Calico Goldfish. But now none of the fish are biting each other. Before fluffy died, I didn't have a bubble thing in it. I wonder if it died from no oxygen? Yesterday, i got a bubble thing that goes on the bottom of the tank and the fish love it. thanks, Debbie

Answer
Hi Debbie,
One of the first most important things to do is to test your water if possible for ammonia, nitrite and nitrate. You can also bring a water sample to your petstore to have them check it for free.

Make sure to ask for the exact levels. For a healthy tank, ammonia should be-0 nitrite-0 nitrate-20 or less

Even though the water may be clear, it doesn't mean it is healthy. There can be dissolved organics from fish wastes that can cause diseases and stress. The easiest way of course to prevent this is to keep up with the water changes.

One thing you didn't mention is how often you did a water change. Many people don't do frequent enough water changes or go by out-of-date advice that just doesn't really work.

Depending upon your aquarium size, stocking level, feeding, and filtration my best general guideline is 30-50% once or twice a week. Monitoring your nitrate levels and keeping them as low as possible is the key to how often and what percentage to change the water.

Poor water quality is the leading cause of fish death and disease. So definitely check your water and as a precaution do 30% water changes over the course of several days, making sure the replacement water is equal in temp your tank and treated with a water conditioner.

I doubt it was oxygen, always possible but most fish who suffer from low oxygen will gasp at the surface.

I hope this helps and I hope things improve!
Karen~