Clean the Filter

Today we cleaned the filter for the large pond. It was really dirty and it has only been a month since the last cleaning. The filter is a 20 gallon waterfall in a 1/2 whiskey barrel fed by two 600 gallon per hour pumps. The water flows into the bottom and pushes up thru 4 inches of lava rock, 1 inch of coarse filter material and 1 inch of fine filter material. One of the pumps pushes the water thru an ultravoilet filter to keep the water clear. I float some water hyacinth on top to filter and hide the top of the barrel.