Well I am wanting to do a say 8 foot rounded koi pond with a small on the side bog garden so the water pumps through it then goes into the pond but part of the pumps output goes to a small waterfall. Now I am trying to get an idea of costs ,I realize that I need a pump that pumps 2X as much water as the ponds size,a biological filter for the gallons in the pond and

maybe a uv clarifier /sterilizer. Realizing a rough calculation is around 1500 gallons it should be okay for koi.

I have been looking online and in some catalogs that I ordered. An external pump seems better since the submersibles are for smaller ponds am I correct ? I think an external biological filter is best for servicing but I'd like opinions. My estimemts are around $600 using an EPDM liner since PVC sounds short lived and cheap..

For plants some bog plants in a side by bog that looks nice and holds water maybe a small PVC liner ... I realize koi eat and ruin many plants so the bog idea seems best.

Well theres my idea ...