Please Help... Dead Goldfishes

Question
I always wanted an aquarium and just 2 months ago bought a small rectangle plastic tank for 3 goldfishes. Later, after 2 weeks of reading and surfing the internet, I realise that it was a bad thing and purchased a 62CM lenght X 21cm width X 21CM height glass aquarium with an Interpret Internal Power Filter, added some Roman Gravels and a few ornaments. I also have a water stone but the power filter has venturi system which adds air to the outflow so I did not add the water stone to the set-up. Once set up, I moved them into thier new environment straight away(I left the tap water in a tank for 4 hours thinking that this would disperse the chlorine/chloromine). Within 2 weeks the smallest of them died of Swimbladder (I was advice that it was a Swimbladder issue as it lay at the bottom of the tank unable to swim upright in the water) I purchased a Swimbladder treatment but it was too late. It was then I realised that I might be overfeeding my goldfishes as I was giving it a flake each everyday, which it gulps straight away. So I changed my feeding pattern to a single flake every other day. 2 weeks later, the biggest of them died again of Swimbladder and the treatment didn't work. Both times I removed them from the aquarium into a smaller plastic tank with the treatment, and water from the aquarium. Just about a month ago, I thought that I was more experienced and purchased another 2 more goldfishes and added them to the only 1 that was alive. I clean the whole aquarium and added them into the aquarium hoping that Swimbladder wouldn't be an issue again. 2 weeks on another one of them died. The culprit, Swimbladder. In the 2 weeks before it died, I fed them a mixture of peas and flake food every other day. I did a 25% water change (I left some tap water overnight and used this water for the change) every once a week. I also have the Power Filter. All still could not stop it from dying. Now, I'm left with 2. Just a week ago, another 1 of them died and again of Swimbladder. I tried feeding it with peas but it didn't want to eat anything. It died a day later eventhough, I separated it out of the aquarium into another tank with treatment. Since it's death, the only 1 (which I call Qi) is left from my initial purchase 2 months ago and it was acting weird just sitting at the bottom of the tank the whole day not eating or moving much unless disturbed. I thought it might be lonely and bought another goldfish to accompany it. This time, I added it slowly after 20 minutes being in a mixture of the pet store water and my aquarium water and did a 50% water change and added a teaspoon and a half of aquarium salt. Thankfully, Qi started moving and swimming more. He seems to be happier with his new found friend. I wouldn't want anyone of them to die. Especially, Qi. I'm planning to only feed them with a half a pea each and a flake once in 3 days. I do a 30% water change every 5 days with tap water left overnight. I'm also gonna add a teaspoon of aquarium salt whenever I do a water change. How bout the tank? When should I clean the tank? What else am I doing wrong? Is my tank to small for my goldfishes? Also, is there such thing as bullying among goldfishes? The new goldfish which I recently added seems to chase Qi around a lot, especially after being fed? Is that normal? Please help!!! Thanks...

Answer
Hi Rashim;

The tank is just too small for goldfish. They need at least a minimum of 38 liters just for one goldfish and yours is only 6. Here are some links to info about goldfish and what they need;

http://www.firsttankguide.net/goldfish.php
http://www.flippersandfins.net/goldfishcaresheet.htm
http://www.kokosgoldfish.com/care.html

Just to keep your current fish alive until they get a bigger tank, you will need to change 25% of the water every other day. Get a water conditioner to remove chlorine and help the fish with stress. A good one also detoxifies dissolved metals that are present in some water systems. It works instantly so all you have to do is make sure the new water is the right temperature and you can add it right away.

Also, read about New Tank Syndrome on my own page about it;

http://www.xanga.com/Expert_Fish_Help

At Your Service;
Chris Robbins