I can move him when he outgrows the 10g, but is he okay in the 10g by himself until he gets about 10inches? Please note that the tank will be overfiltered, and water changes will be done once or twice a week, 20-20%. I just wanna make sure he grows okay, and there's none of that insides-growing-but-outsides-not thing or something similar!

Someone with more experience will be able to give you some better advice but....

How wide is the tank?

One general rule I was taught is that you shouldn't keep a fish that has a length half as much as your tank is wide, so you might have to move him before 10 inches depending on how wide the tank is, I doubt a 10g tank will be 20 inches wide.

Someone might want to confirm that rule though, I heard it from word of mouth and dont remember reading it anywhere.

EDIT: Spelling

This post has been edited by Karuna: Nov 9 2006, 04:04 AM

Well I am no expert but I wouldnt wait until he gets 10 inches to move him. Most 10 gallon tanks are 10 x 20 inches and he would have a heck of a time being comfortable turing around, plus gold fish require twice as much water volumn per fish than small tropical fish, so at 5 inches he would be maxed out as far as the water volumn per fish goes. And just because you over filter the tank doesnt mean that you can grow the amount of benificial bacteria needed to keep his tank biologically clean, plus if your water is moving too fast in the aquarium the bacteria wont have the time needed to clean the water before it passes over it. Thats just my 2 cents.

no, you cannot leave him in there until he is 10 inches. Over filtered or not, you wouldn't keep a ten inch oscar in that tank and you can't keep a goldie in one. The inches per gallon rule falls completely apart with large thick bodied fish. a 10" goldfish is going to create a lot more waste than ten neons.

minimum on fancy goldfish is 20 gallons with another ten for every additional fish (ie: 30 for 2, 40 for 3)


you can keep one in a ten gallon temporarily, but you will notice that even at 2 inches or so it's going to start looking crowded. If you have any more questions, you should check in the Coldwater section.

This post has been edited by starrynightxxi: Nov 9 2006, 04:46 AM

Oops, I'm sorry, I messed up, I meant 4 inches, not 10

well, until it was 4 inches, yes, you probably could, but moving it as soon as possible would be advisable

[edit] also! makes sure that you don't decorate the fish's tank with anything that has sharp edges or points (rocks, plastic plants, many tank ornaments) because the "bubbles" will tear and empty.

This post has been edited by starrynightxxi: Nov 9 2006, 11:05 PM

Ok, thanks for the advice. I'll be sure when I get the goldie I'll be extra cafeful with decorations too.

On the fish index is said Bubble Eyes only grow to 5 inches, so it would be okay right? I know other goldfish grow to over a foot, so it's those that you really need a bigger tank for... right?

IMO and probably not to others but 10 gallons is doable for bubble eyed fish. They arent the fastest growers and dont get too big. They cant really swim that well due to the sacs so are basically handicapped.
As long as the filter has lots of medis for bacterial growth and you are prepared to work at keeping the tank really clean then you could try it.
Youve said you will upgrade if needed so i dont see a problem.
As mentioned, no sharp objects and place some filter wool or matting over the filer to stop the fish hitting any corners.
These fish are more delicate and require some heat in the water, so a heater set at around 20 - 22 c will be appreciated.

well, comets and commons and their ilk will get to 12+ if properly cared for. Everything i've read about fancies is that they will generally reach 8-10. If bubble eyes only get to 5 then yes, I suppose you could keep one in a ten gallon. I assumed they got as big as other fancy goldies.

However, you might want to look into getting a bigger tank anyway if you can. My oranda was much happier to have some company of her own. They aren't a schooling fish, but are still very social animals and will appreciate another FANCY goldfish to play with (make sure it's another fancy, perhaps even another bubble eye to prevent agression and damage to the eye).