The weighted impact of each advantage and disadvantage is what should inform your decision on whether to use an external pond filter. The best pond filter will vary depending on several factors unique to pond including the location, purpose, size, type of marine life, and population of marine life.
Pro: Minimal Disruption on Pond Life
The process used on an external filter is that he water is sucked into the filter, cleaned and pumped back to the pond. At all times, the filtered and unfiltered water is kept separate. Since the filtration sis taking place outside the pond, waste extraction is achieved without disturbing the pond’s fauna and flora.
Pro: Aesthetically Attractive
An external filter can be operated far-removed from the pond’s immediate surrounding. The presence of mechanical appliances in close proximity to the pool is an eyesore. Longer inflow and outflow pipes may be required but the cost is marginal.
The mechanical operation that defines external pond filters means that their cost of production and sell price are above their submerged in-pond alternative.
External pond filters are large and bulky. Movement, stationing and installation take more effort than that required for a submerged filter.