Balas are stricly tropical fish, native to SE Asia and require water never less than about 72 deg., so you would need quite a pond heater.

Also, while they are attractive when viewed from the front, from above, they would look pretty much like oversized minnows. They also get quite large, up to 16" and in a large pond, might exceed even that. They also need to be kept in schools, or they become very aggressive.

If your pond will exceed 1,000 gal, are you sure you don't want some nice Koi? Or, for a smaller pond, Pond Comets, or Wakin? The Koi and Wakin especially, are most attractive when viewed from above. But mainly, they will also winter in a pond with only an air hole in the ice and with some patience on the owner's part, will become very tame and confiding.

However, if you are bound and determined to keep tropicals in a garden pond in an area that freezes and are thinking of a greenhouse as well, your obvious solution is a real, working, heated greenhouse with a pool in it. Otherwise, you should plan on a very large tank somewhere in a heated area for winter, because it takes a huge amount of energy for tank heaters to produce a temp. rise more than about 8 - 10 deg. above ambient air temp.

If you do some web searches on aquarium tank heaters, you will find interesting articles on how water temps affect fish, and charts, to tell you how much wattage per gallon of water in relation to ambiant air temp is necessary to maintain the proper temps for tropicals.

Thanks for the info. Our pond is about 300 gallons and I wanted 4 of them, but no I am not dead set on them. I would have to make some kind of heating provisions because I would not have anywhere indoors to take them, so maybe I'll hold off on getting them and see if I really want to build a greenhouse type structure over my nice new garden pond I just dug!!!
Main reason I don't want Koi is because EVERYONE does koi!! I just want something different that you aren't going to see in every one elses pond. I will keep looking.
Thanks
Becky

Becky: I also have a pond, but no Koi and yes, everyone seems to have them these days. But for a 300 gal. pond, which is too small for Koi anyway, there is an ideal pond fish that is NOT common and actually far hardier than Koi.

IF you can find them, try Wakin. They are the common pond goldfish of Japan, but rare here, which is a shame as they are the perfect small pond fish for our Midwestern climate and really lovely. They can grow to about 16 - 18" but in a 300, would not likely exceed about 12". They will winter under the ice quite well, so all you would need is a small floating stock tank heater to keep an air hole open on the surface.

Once you see Wakin you will either be unimpressed, or fall totally in love, as I did when I saw them in Japan, after which it took 2 years to finally find an importer so I could buy some high quality Japanese stock.

I now have 14 Wakin and one of them is so mad for Romaine she actually leaps up from the water grab it, so I named her Flipper.

quick note, Balas are incredible jumpers, and if you were to somehow keep them warm, you'd have to rescue them everytime they made an escape!

I currently have 3 Bala sharks in my 20 gal. tank.They have been in the tank for over a month,in the last two days they have stayed in the same side of the tank just swimming circles around each other.Is this normal or should i be worried?