Bottom drains explained: which one is right for your koi pond?
Why koi ponds need bottom drains, 50mm versus 110mm, concrete versus liner ponds, and when to use diffuser, conversion or surface-mount drains.
What size UV clarifier does my koi pond need?
How UV clarifiers clear green water, how to size one from your pond volume and flow, and how to keep it working.
How to choose the right drum filter for your koi pond
How drum filters work, how to size one from your pond flow rate, gravity versus pump fed, and what else your filtration needs.