Rocky,
I assume you are talking about weeds on the perimeter of the pond as opposed to weeds in the pond itself?
Reward has been recommended here for that use and I have used it very successfully and hence recommend it to you...but it is non-discriminatory meaning it will kill whatever plant it touches.
Do not use RoundUp as many problems have been reported with the surfactant in RU causing severe harm to amphibians and possibly fish in your pond.
Now about vinegar and bleach...interesting that you consider them safe for your pond. Are you sure that vinegar and bleach are both safe to fish and swimming? I'm not an expert, but common sense would tell me that bleach is toxic to fish and vinegar in a swimming area, well to each his own.
