That is the $64,000 question. The size of the filter really doesn't have
anything to do with the size of the pond. It is dependent on the bio load,
like how many fish, turtles, frogs, how often they are fed, how often
10 -25% water changes are performed. Generally, for most ponds, you can get
by with a filter that is rated at twice the capacity of the pond, but due to
fish load, I am running filters that will handle 4 times the size of the
pond. As for a filter that doesn't need cleaning, there are none. Bigger
filters last longer between cleanings. Bead filters are easily backwashed
in coat and tie, if your so inclined. Gravel filters are heavy and dirty to
clean. Water troughs with screen or other media, are somewhere between the
extremes. Veggie filters seem to be little maintenance during the year, but
if they are working, will make for a lot of plants to divide.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html

"DD DDD" wrote in message
...
Thank you. Whats a good filter for 300 gallon pond. Thanks