What filtration would be needed for keeping abalone in cold salt water?

being a grazer i would say very little to get the algae growing, so no zeovit.

Someone on trademe sells baby paua and /or instructions from time to time.

Very good filtration, high dissolved oxygen, water current and good quality food. Ab's are a very basic biological animals and don't handle stress all that well. Keep the parameters good and they grow fast. A paua farm is a good place to get stock and information. One of the best I know is in Nuhaka, Mahia. Rob@Aquagold