I usually advise folks, if you can hear your pond splashing and babbling from ten feet, there's probably enough oxygen. Signs of inadequate aeration include gasping at the surface , or if less severe, the fish do not play - they just act lethargic. Another section describes a compound which actually ADDS oxygen to the water in emergencies and so the book might be just what you're after. Aeration becomes of paramount importance in the summertime. In the winter, low dissolved oxygen would be just about impossible.
Trasnporting fish is dangerous in warm weather.
The use of some ice packs in the water tank with the fish may reduce losses. Introduction to the video. Get an AquaDyne. It's truly excellent in many ways. Koivet is proud to provide a Health updates list .