goldfish dieing off one by one

Question
I've been having major problems with my three goldfish.  I owned two of them for about 8 months in a 2.5G tank, and just recently moved them into a 20G along with a new goldfish.  They've been in there for about 3 weeks and have been perfectly fine.  A few days ago the two older ones started hanging out at the bottom of the tank, being very lethargic and not responding to food.  I added aquarium salt and fungicide, and had the water tested.  The water looked fine.  To make a long story short, both of the fish ended up dieing despite my best efforts.  
Two days after the second one died, my new third goldfish is starting to loose his activeness, and is staying at the bottom of the tank.  I've cleaned the 2.5G tank completely and have moved him in.  What can I do to keep him alive and healthy?  I want to get more goldfish, but I don't want to feel like i'm giving them a death sentence by puting them in my care.
I only been feeding them once every other day since they started getting sick.  And I've also added a amonia filter to the 20G tank.
Please help!!


Answer
Dear Alyssa,
Thank you for explaining your fatal gold fish situation to me. Your new goldfish might also die, but let me offer some advice to help you get started again. "Same tank,new faces." I do encourage you to start again if you have the time and energy, since all of us lose a few fish now and then. Learning the proper way to keep fish is a good thing to know and pass along to others. If it's a hobby you think you would enjoy, you can learn the ropes and have better luck in the future. Here's a short summary. You can find more info. in books, on the Internet, and from talking to people at the fish stores. You can always learn something new about keeping fish.

1. The leading cause of fish loss is overfeeding. If your water is cloudy or your filter gets clogged, you are overfeeding. Fish are like little fairies who don't need to eat much. Two or three flakes per day per fish should be enough. If they grow larger, you can increase it a little. If you put food in and the food touches the bottom, you are over feeding. A hungry fish would never let food touch the bottom. Fish are terrible gluttons and will eat whatever you give them. They will act hungry all the time, but they really just want attention.

The best way to feed them is first get their attention so they come to the top. Then drop one flake at a time until each fish has and a few bites. That's it for the day. You can feed them every day, but a box of fish flakes should last forever.

Another thing that might contaminate the water is aquarium plants. My experience with live plants was that the fish try to eat them, they die, rot, and pollute the water. I prefer silk or plastic plants. Also, change those out when they become difficult to keep clean.

2. Cleaning the tank. The biggest mistake people make is to remove too much water at the time of cleaning. Fish don't do well in fresh water. They actually need an ecosystem of natural bacteria to protect their coat, help them breathe, and help break down fish waste in the tank. There is a chemical available in aquarium stores called "Cycle" that provides the biology to make fresh water more like the natural habitat they need. Keep the bottle in the refrigerator and follow the directions on the box.

Clean the tank once a week or every two weeks. First scrub down the inside glass with a small sponge used only for the aquarium. Let the water settle.

Buy a fish syphon vacuum cleaner at your fish store and run it around the bottom of the tank in the gravel to remove waste material. You should be able to accomplish this by only removing 10-20% of the water. When you fill the tank, use only bottled water. If you use a heater (shouldn't be necessary with gold fish), make sure the water is the same temperature as the rest of the water in the tank. (If you don't use a heater and the tank is room temperature, use bottled water that is room temperature.) Add the proper amount of Cycle.

3. Illness. If your fish get sick, do not buy medicine at the fish store. Usually fish get sick because of over feeding. Adding all sorts of medicine will not help. The only thing I've found that will help is the ordinary Stress Coat (or similar product) that you get at the aquarium store. It's basically just aloe vera and it helps protect the fish's silky coating. Never touch fish or pick them up. Your hand will wear away their coating. If you must pick up a fish for some reason, add extra Stress Coat to the water. The fish at the place where I work came down with terrible Ick. I thought he was a gonner, but I made very strict rules about overfeeding and changed his tank more frequently, adding Cycle every time. I called him up to the top and dumped a few drops of Stress Coat directly onto his head where the Ick was worst. After three treatments like that he completely recovered.

Also, you might consider something else besides gold fish. They are really messy fish. They are hearty, though, so it might be good to try again with one gold fish (or the fancy gold fish) until you feel more confident. Another good choice is a beta (just one by itself) because they don't need filtration, aeriation, heaters, etc.

You say you have a 2.5 gallon tank. It would be a good size for a beta. However, if you meant a 25 gallon tank, and if you already have the whole set up, you might get one goldfish and a plecto, or something like that. Plectos are little catfish that resemble sea monsters and they are very hearty. They can also be vegetarian and survive on one spirulina tablet per day. They also enjoy occasional fresh vegetables such as zucchini, lettuce, etc. They are friendly and great show offs. They can get along with another fish if the tank is not crowded and they don't need a heater. To keep a plecto and a goldfish, I would suggest a large tank, maybe 12 - 30 gallons.

I hope this helps.
Sincerely,
Nori