Generally I release or kill at the time of capture, but to keep alive I have always just done as Dave says and regularly topped with fresh water and the exchange has always kept them in good nick, and 2-3 times an hour is plenty.Peril said:Simon,
I've got penty of deck space so I just plonk an esky on the deck with a bucket next to it. Bucket in some fresh water ever half hour or so and the fish show no ill effects - still frisky