Pond servicing - another call

Got another call, this time from a Mrs Chandran asking to service her koi pond. She sounded desparate and yet very patience. Her koi are in trouble with most swimming around on the pond surface fighting for more oxygen. For such cases, never mind that we have not agreed on a price. We have decided to make the trip this evening to see what we can do to help the koi and Mrs Chandran.