Out of curiosity, do ya'll suggest not vacuuming the gravel in your tanks too?!
The garbage on the bottom of the pond is decaying and causing every problem everyone screams about in their tanks. It's just that the pond has a good air/gas exchange rate outside and your only looking down on it (not thru it). If your pond is 2ft deep and doesn't have good circulation the water is going to stratify, cause the garbage to almost stop the decay process, go fully anerobic causing pain/death/destruction, fish doing the permanent backstroke and a very icky smell ! ( it's a biological time bomb and when it goes, everything could be dead by morning )
Besides if you clean it, people won't say ' whats that junk on the bottm ? '
P.S. I keep mine clean and then LIE about how little time it takes to maintain.