new fishtank

Question
hi , I just bought a new 54 gallon corner tank .it came with the light and Glass top . so far so good........
here's the biggy.............
i have fantails gold fish (3) and longtail gold fish (3)
have had  these fish over 1 year and have been proud of them even lasting for more than 1 year.......lost 1 fish, 2 days ago by finding it 20ft from the tank . so what to do? go buy a bigger tank . how do i set up this tank with what i need not by what i have been using ................please cover the topic as if you where actually doing this for your own tank ..........i need to know what to buy and what not to buy...............base these thoughts on the fish i have and their longevity and taking into consideration the thought of other fish joining in soon .......plants would be nice also .......
thanks for this and i would love to hear back .......thanks and Merry Christmas.

Todd and his Boys Brandon and Benjamin

Answer
If I was to set this tank up for myself, I would use a back hanging power filter rated for a tank twice its size, your dealing with gold fish and they put off a huge amount of waste so I would not want water quality to be an issue. Second go with a medium sized gravel no more then an inch thick and have it whatever color you want. Although gold fish like cooler water then tropical fish its good to have a heater just in case you need to heat up the tank for colder nights or when treating with medication, keeping the tank around 74F is a good idea. Decorations really aren't that important since gold fish really don't use them much to hide so go with whatever suits your eyes.  Aquarium salt in the tank is a good idea to help bolster the fish health and keep parasites down, 1 teaspoon per gallon of water is a good maintenance dose. When dealing with plants go with small leafed plants that are very hardy, goldfish will pick at them and so they need to be able to take some abuse, also make sure you have the plant anchors holding them down or the gold fish will spread them all over the tank.  A good water conditioner is a must and weekly water changes of about 15 should be part of your standard maintenance schedule. A tight fitting all glass lid with a strong florescent light will keep your fish from jumping out and bring out the best in there colors.  Make sure you allow the tank 4 weeks to cycle prior to adding the goldfish into it and once you do add them in keep an eye on water quality for the first few weeks.