Buying a used tank?

[Shanks]

Hi, I've been planning to buy a second hand fish tank, but do I have to worry about disease? Like, if the previous owner's fish died of a disease that can't be "washed out of a tank?" or is it perfectly safe if I wash the tank, and clean it? Also, if I plan to raise goldfish only in the tank, do I need a heater?

[pharasalia]

Many people buy used aquarium equipment with no problems whatsoever. If its drained and cleaned, I doubt there will be much chance of any disease contamination. Don't use soap to clean it though, use vinegar or a small amount of bleach mixed in hot water... and then rinse it a million times.

Once you get the tank and get it cleaned you should set it up and cycle it before adding fish. If you are going to do a goldfish only tank, make sure it is large enough for them before buying. Goldies require a lot of swimming space contrary to popular belief. 3 fancy goldfish can grow up comfortably in a 55g. You need at least 30g just for one... then figure an extra 10g per fish. This is the fancy type - your orandas, fantail, telescopes, etc. The feeder/comet type swim much faster and get up to a foot long so you would need a much larger tank for that type.

A heater is going to depend on what your water temp stays at once you get the tank set up. Goldies don't need it ice cold or anything. 65-74 or so is a good range.

[THE V]

If you truly are concerned about disease being transmitted from the previous owner this is one way to eliminate it. The mix that pharasalia recommended would remove some bacteria and mineral deposits but not truly disinfect it.

Micro 101 -- The most effective way to remove the majority of pathogens and viruses is with a 10% bleach solution. I'm serious about the 10%. not 5% or 15% and definately not 80%. So its 1 cup of bleach to 9 cups of water. This matters because 10% is the most effective concentration of bleach. More or less limits or destroys it's effectiveness. Put enough of this solution in the tank to cover the rocks and most the equipment that you want to sterilize (tubing, rocks, etc). Put it outside so the fumes don't make you pass out and leave it for 1 hour (10 minutes are required to sterilize a clean surface, a used tank isn't clean). Then wash down the sides of the tank using a sponge and the solution. Drain and rinse the tank with clean tap water. It is best if you can lay the tank on its side so that the water will run out. Filling the tank completely and then dumping it will tank 1000 times more water (look up dilution calculations). When you can no longer smell the bleach it is done. Bring that tank back inside and fill it up. Be sure to add some dechlorinating solution to the tank before you begin to cycle it.

[Buckdog]

If you truly are concerned about disease being transmitted from the previous owner this is one way to eliminate it. The mix that pharasalia recommended would remove some bacteria and mineral deposits but not truly disinfect it.

Micro 101 -- The most effective way to remove the majority of pathogens and viruses is with a 10% bleach solution. I'm serious about the 10%. not 5% or 15% and definately not 80%. So its 1 cup of bleach to 9 cups of water. This matters because 10% is the most effective concentration of bleach. More or less limits or destroys it's effectiveness. Put enough of this solution in the tank to cover the rocks and most the equipment that you want to sterilize (tubing, rocks, etc). Put it outside so the fumes don't make you pass out and leave it for 1 hour (10 minutes are required to sterilize a clean surface, a used tank isn't clean). Then wash down the sides of the tank using a sponge and the solution. Drain and rinse the tank with clean tap water. It is best if you can lay the tank on its side so that the water will run out. Filling the tank completely and then dumping it will tank 1000 times more water (look up dilution calculations). When you can no longer smell the bleach it is done. Bring that tank back inside and fill it up. Be sure to add some dechlorinating solution to the tank before you begin to cycle it.

Well said.