Which one is beter ?

Hi,

I'm planning to buy another brand new aquarium for my goldies and I
was thinking should I put it outside the house (so that they can get
natural sunlights) or should I put it inside the house (using UV
light to keep them warm).

Because I saw all of the breeder that I met they raise their goldies
in a pond outside in the open and the only protection they use to
protect them from the heat are mosquitoes net, as this will help not
to overheat the water.

Any suggestion ?

Thanks

Cheers
Nanik