The trouble is, some people's idea of 'pretty big' may not be the same as somebody else's. I remember dealing with someone, a few years ago, who had a 'huge' tank for their goldies; turned out to be a two foot/60l which, to me anyway, is 'small'.
To reiterate; to keep a channel cat in good health, your pond is going to have to be AT LEAST 12 foot by six; that's roughly 3.5 x 2 metres.
