I like to stay on the positive side of things, so I hate to say I "hate" anything. But, yes, there ARE some things about ponding that get pretty irksome.
For one thing, I hate it when you do everything right, and things don't go as they should. For instance, the two "self cleaning, back flushing" pressurized bio filters that I spent good money on, but do NOT clean themselves "with the turn of a knob." In fact, neither one cleans itself in any way, shape, or form.
Every time I turn off the pump, and then manually disassemble the filter and then hose off the media inside, I am just FURIOUS that the manufacturers didn't trouble-shoot their product, and made claims that were not true, and I'm stuck with an expensive filter that is a pain to maintain.
The other thing would be joining the others who hate loosing fish or plants, especially to trespassing animals or birds.