I am just starting my first koi pond build. Pond will be sleepers about 2ft high and I will dig down another 2ft. Pond will be 10,000l volume. Have purchased Kockney Koi 10000v filter but thatís as far as Iíve got. I know I need a bottom drain and skimmer but as for the plumbing and pumps. layout etc, any advice greatly appreciated!!