Your right Parsley re. Goldfish only in ponds. As long as the volume of tank is enough for the fish and tank parameters are good then there is no reason why you can't keep them in doors.
I wouldn't do it as I think they are just too mucky and grow to big for anything but really big tanks. It's all about opinion and thats just mine - doesn't mean it's right!
As to the pheromone argument - I completely disagree about that, fish growing to the size of tank is rubbish (again in my opinion). Stunted growth in small tanks is hardly fair on the fish and can lead to shorter lifespan and health problems etc obviously there are always exceptions - goldfish have been kept in grossly undersized bowls with no filter and lived for years! The vast majority of fish kept like this don't last as long as they should though.
1xTrigon 190
3 Clown Loaches,14 Cardinal Tetras,8 Rummynose Tetras,6 Cory Trileneatus,6 Hatchetfish,4 otocinclus,1 SAE,1 Bristlenose,, 10 amano Shrimp, 1 pair Apisto Agazzizi. 3 Blue Discus
Anubius Barteri,Crinum thianum,Limnophilia sessiflora,Rotala rotundifolia, Echinodorus Blehri, Ech. Parviflorus,Ech. cordifolius, Ech. Tenellus, nymphaea lotus, Hygrophilia polysperma, Microsorum pteropus,Lilaeopsis brasiliensis
1xRekord 60
Blue Lobster, Flash plec
2 Anubias Barteri, 1 Microsorum pteropus
12 litre tank - 3 Glass shrimp, 4 japonica shrimp
1 Anubias Barteri, Riccia, Eleocharis acicularis
Coming Soon - Bluedave's 5' Bullnose Marine Divider (Watch this space!)