We were approached about 10 years ago by the management of Salisbury Crematorium because for years they had a problem of algae blooms in their patio pond. We cleaned the pond out holding the goldfish in a holding pool. We built an under-gravel filter which you can see being constructed and installed 2 high quality pumps. The filter was a bespoke design for that particular pond and was installed in the base of the pond and gravel was spread over it.
The under - gravel filter design is based on the old school fish tank filter. The water is sucked through the gravel by the pump, through the plastic tubes that have holes in them that sits under the gravel. The gravel acts as the biological filter media that holds the bacteria that cleans the water. We recommend this type of filter for large ponds because once set up and running there is minimal maintenance and i can guarantee clear water on a long term basis. The pond now has crystal clear water all year around and Aquatics Management maintains the pond when necessary.
