Goldfish in 20 gallon tank??

Discussion in 'Cyprinids (includes Goldfish)' started by Hamham, Jul 13, 2015.

  1. HamhamNew MemberMember

    How many goldfish can I put in my 20 gallon tank? Can I put like 5.
  2. AquaristFishlore LegendMember

    Your new thread.

  3. Et tuValued MemberMember

    Honestly, a 20 is to small for even 1 goldfish.
  4. lbonini1Well Known MemberMember

    Hi there! You can only have 1 Goldfish in here and that would be a Fancy Goldfish. I would recommend over filtering if you're going to go this route though.
  5. BornThisWayBettasFishlore VIPMember

    I second the above, what Ibonini said. ^^ Welcome to Fish Lore!!!! It's good to have you here!!! :D
  6. PuffPuffWell Known MemberMember

    Goldfish can grow to be over a foot long in most cases but need a lot of space to swim. They also produce a lot and I mean a lot of waste, which means that you need a large amount of water to dilute their waste and a large colony of bacteria to convert the waste into less harmful chemicals. So a bigger tank is require then the one you want to get. It's possible to work with what you have but you need to be on it constantly becoming more of a headache then actually enjoying the tank.
  7. HamhamNew MemberMember

    Goldfish growth

    yes I agree with you all! But the type of goldfish I'm getting from the store says it only grows to 6". So if I have a 20 gallon tank how many of those can I put in?
  8. PuffPuffWell Known MemberMember

    for a fancy goldfish i say a 30 gallons for the first fish with 10 gallons for each extra fish. The tank needs to have a minimum length of 3 feet to allow swimming room.
    for a common goldfish 40 gallons for the first fish with an extra 12 gallons for each extra fish. The tank needs to have a minimum length of 4 feet to allow swimming room. Single tail goldfish are more suited to a pond when they are near full size to give them swimming room.

    this is just my suggestion, i had goldfish that get way to big. but in your case i say within a year the gold fish can get up to 6".

    You might be surprised to know that common goldfish can reach up to 10″ and fancy goldfish can reach up to 8″, so you definitely need a big tank for them!

    so 20 gallons for one fancy goldfish.
    and at least 30 gallons for common goldfish.
    Last edited by a moderator: Jul 13, 2015
  9. LiterallyHydroWell Known MemberMember

    I wouldn't do 30 for a common goldfish. Even a 55 is pretty small given they can grow to a foot long. It's best to just let them be pond fish like koi.

    I also wouldn't do a goldfish tank smaller than a 40B just so you could have a second goldfish. Maybe others will disagree but I personally think that goldfish are pretty social and would enjoy having the company of another goldfish.
  10. PuffPuffWell Known MemberMember

    yeah i agree, every tank i seen has more then 1 gold fish. and they can grow as large at 24". my god
  11. lbonini1Well Known MemberMember

    It isn't just about if it grows large or not, it's about the bio-load of the fish and a goldfish are very messy so their bio load is very large. Do you know the Nitrogen Cycle? If not, find out by clicking the blue words. Each fish needs enough space for waste dilution and if these limits aren't respected then it'll be very hard to maintain good water quality.
  12. PuffPuffWell Known MemberMember

    in this case even an external filter (which is a larger filter) will be better for the amount of bio-load this fish gives off.
  13. HamhamNew MemberMember


    How do I take well care of guppies? I have a 20 gallon tank.. How many can I put in it?
    Also do I need a heater for them?
    any info wil be helpful
  14. BornThisWayBettasFishlore VIPMember

    Guppies aren't that hard to take care of, I've kept a couple before. They're really fun and pretty!

    I'm not sure of the exact amount you could have in there, but definitely more than goldfish. :) If you do get guppies, make sure to get all one gender or else they'll have a ton of babies; they're livebearers.

    Yes, guppies need a heater.

    There are so many different color and pattern variations of the guppy that I'm sure you'll find something you like! I've even seen albino and pure black!
  15. lbonini1Well Known MemberMember

    I recommend you start a new thread so you get responses for what you're looking for and nothing else. :)
  16. Et tuValued MemberMember

    What he ^ said.
  17. HamhamNew MemberMember

    How do I start a new thread???? Please help
  18. BornThisWayBettasFishlore VIPMember

  19. Anders247Fishlore LegendMember

    Welcome to fishlore!
    A 20 gallon is too small for any type of goldfish, fancy or not. Some types can get up to 10 inches, the smallest being 6 which is still too big.
    Common goldfish get over a foot long, a 40g is too small for them. They are best off in 150g+ tanks or in a large pond.
    I would go min 40 gallons for one fancy goldfish.

    As for guppies, if they are the only fish then you'd be able to do up to 15 as long as they are all males. If you had females you'd end up with an overstocked tank.
  20. yogosans14Valued MemberMember

    40 gallons for ONE single fancy!?!?!

    I'm sorry but no. I recommend the op watch solidgolds "tank size" video. She recommend 20 gallons per fancy goldfish. It's crazy how many different opinions they are for these fish. Very annoying honestly. *sighs*