This is a discussion on 37 gal tank, can I put goldfish in it? within the Cyprinids and Atherinids forums, part of the Freshwater and Tropical Fish category; -->
Two fancies is completely acceptable in a tank of this size, Poleren. It is just a matter of adequate filtration and maintenance....
I wouldn't put 2 in a 29, nor would I only put one in a 29. They are group oriented fish which is why I don't believe they should be kept in less than a 4 foot tank (to accommodate 3-5).
We all have to decide for ourselves how much space we want our fish to have. I'll never understand why people want to cram the biggest fish they can into the smallest tank they can, mainly because I like to watch the fish swim around the tank.
So the question you have to ask yourself is this - are you a bare minimum fish keeper? That is the point of all the debate, no? What's the worst "acceptable" setup we can provide?