I've got my 100g preform absolutely perfect, the little pump and filter I have are nothing, but that's all the pond requires. I clean it twice a week. The biggest problem I get is when the filter starts to get clogged and cleaning it isn't as effective as before, the filter will build up O2, and this saps the pumps power. When this happens twice in a row, I chuck the filter and put in a brand new one. Has happened twice so far, so it's like a monthly occurence.
So while my larger pond might be more stable in regards to ammonia or PH, it takes a lot more effort and machinery to keep it clean, where as I can almost spit into the small one to recycle the water and keep it crystal.
So while my larger pond might be more stable in regards to ammonia or PH, it takes a lot more effort and machinery to keep it clean, where as I can almost spit into the small one to recycle the water and keep it crystal.