The Formal Raised Pond
The pond holds approximately 4000 gallons and is 15 ft long x 7ft wide x 7ft deep. It is block built with hollow blocks, backfilled and reinforced with steel rods and steel mesh. It has a shaped and contoured bottom with rounded corners and sides and is lined with Fibre glass. The pond has about 30” above ground, which allows the fish to be closer, more friendly and is safer for my young daughter. A wooden pergola covers the pond and is top covered with mesh for extra shade. The sides of the pond are capped with stained, machined hardwood to match the pergola.
The single bottom drain gravity feeds a 30” vortex to a Nexus Easy and is pumped back to the pond by an Aquamax 10,000 via a 55 watt ProClear UV.
A modified skimmer feeds an SS020 Mega pump through a WaterCo Multi Cyclone to a Fluidart Challenger 60 bead filter then back to the pond 18” below surface.
The Nexus has a 50 litre Koi Pro air pump to agitate K1 media and bio chips. A separate Seco 50 litre air pump feeds a 760mm long rubber air diffuser .

The filters are housed in an 8 ft x 6ft wooden shed. The waste from all filters is piped straight to drain.

The KOI
There are 32 fish ranging from 6” to 25”. They are fed a variety of food including: Saki Hikari, Fuji, E.A.  Health and MediKoi, five times a day at 05.30, 08.00, 12.00, 16.00 and 20.00 hours through an autofeeder. In the summer months they are also hand fed wheatgerm bread and worms by my daughter. In the winter they are auto fed once a day at 10.30am with wheatgerm.
The pond is treated monthly with E.A. blanket weed inhibitor which seems to keep blanket weed away.
The cleaning regime is to flush the vortex, Nexus Easy, and cyclone and to  clean the Nexus foam weekly. The Nexus base and bottom drain are flushed monthly, as well as cleaning the airstone.
Ever six months I change the UV bulb and clean the Nexus airlines.I also open the bead filter.
All water top ups are through an E.A. purifier, this process I hope to automate soon.
My next addition will be a 50 gallon veggie filter fed from a 1 ½” side drain by a 6000ltr Laguna pump through a 4 kw heater and a Dura 6 heat pump,….and, of course, a couple of fish from Japan!

The History
The pond has been running since August 2007,with  the Nexus and vortex. The Nexus initially took a long time to develop a bio mass as the vortex took most of the waste out before it reached the Easy, but regular doses of ActiveX helped substantially.
The bead filter was added in April 2008 and dosed with ActiveX resulting in it maturing a lot more quickly. Bio chips were added to the Nexus in July 2008 and are now maturing well. The chips and K1 were well soaked in permanganate before set up to assist in adhesion of bacteria.
I lost 2 fish in early days to ulcers & fin rot, probably due to the filters not being mature enough. I have had a lot less problems since adding the bead filter. I had a outbreak of Tricodina and flukes, both were treated successfully, thanks to Graham, with no losses .
The multicyclone was added in August 2008. I’m not sure if it is justified yet as the skimmer grid and pre filter on the pump take out most of the waste. The summer season feeding will test this.
The pond is covered with polycarbonate sheeting during the winter period, which keeps water about 2 degrees above outside temperature.