Wanting To Start A New Gf Tank

[FWFishLover]

Well My Birthday Is Today And I Lucked Out On My Dad Saying He'll Buy me ANY one fish and i ended up getting near $140 cash (with more to come)
so i thinking i would build a tank. which basically is i go to the LFS and say i want this size tank which will be whatever i can afford (20g minimum) after decor and substrates and a filter.
so i plan on getting a fancy GF (not sure to which) and i was told that i could fit one into a 20g by forum users. (i'll probably get a bigger tank due to how cheap build a tank method can be) so here are my questions:
1. sand vs. gravel
2. heater or no heater (im pretty sure none due to coldwater fish)
3. can cories survive in coldwater (GFs are BIG wasters so i do need a back up plan besides a siphon)
4. length wise or width wise for the tank
5. will it be happy (he'll be the only one there)

 

[Wills]

Get a 125 liter tank 3 foot Any of the fancies will be suitable, some people try tank mates but there are risks with all of them so I wouldnt recommend any. Make sure you get a good external filter at least 10x your tank size per hour. Sand or gravel is okay they dig and one thing to be careful of is not to get a stone they can get stuck in their mouth. I would get a heater to avoid temperature fluctuation which can cause stress they are usually only £10 ish so its just nice to be safe with it rather than risk again. I think a lone goldie would be very happy in a 125liter and would be a good choice If kept correctly I would be a big credit to your fishkeeping choices

 

[FWFishLover]

Get a 125 liter tank 3 foot Any of the fancies will be suitable, some people try tank mates but there are risks with all of them so I wouldnt recommend any. Make sure you get a good external filter at least 10x your tank size per hour. Sand or gravel is okay they dig and one thing to be careful of is not to get a stone they can get stuck in their mouth. I would get a heater to avoid temperature fluctuation which can cause stress they are usually only £10 ish so its just nice to be safe with it rather than risk again. I think a lone goldie would be very happy in a 125liter and would be a good choice If kept correctly I would be a big credit to your fishkeeping choices

thanks for the advice and would you happen to know what 125 liters is in gallons for i live in the US

 

[Truck]

33 gallons, I doubt you'll get one that size in the US, they're only made by Juwel and Fluval, a 40 gallon would be fine for 2 fancy goldfish as long as you used an external filter, something like a tetratec ex 1200 would do fine.

 

[FWFishLover]

33 gallons, I doubt you'll get one that size in the US, they're only made by Juwel and Fluval, a 40 gallon would be fine for 2 fancy goldfish as long as you used an external filter, something like a tetratec ex 1200 would do fine.

yeah i've only seen 10g tanks that sell by themselves.
but i'll figure something out

 

[TucanSam007]

get a 29gallon, they are a perfect small-medium size

 

[Gurglar]

Don't get one goldfish on its own there a social fish and prefer the company of others.

You won't need cories as goldfish are scavengers and will pick at the substrate searching for food all day, also pretty sure cories won't eat the poo of goldfish just uneatin food which goldfish pick up anyway.

Sand or gravel would be fine.

Goldfish are a coldwater fish so no heater is needed.