I am going to guess that its the easiest to maintain also. Continue manual weed removal. Lime the pond this winter. Fertilize the pond in early spring. This is after removing some LMB and adding some adult 5" BG to get the pond back in balance. Both of the owners are very busy so I am guessing this is the option that they will like best. I will ask them this weekend.

Give a man a gun and he can rob a bank, Give a man a bank and he can rob the world.