Garden Pond API

Garden and koi-pond maths as an API, computed locally and deterministically — the numbers behind a backyard water feature, so you do not have to guess at the hose. The volume endpoint turns length, width and average depth into the water volume in cubic feet, US gallons and litres, applying a shape factor (rectangular 1.0, oval or round 0.79, irregular 0.85) because a liner pond never holds the full bounding box: an 8 × 6 ft pond two feet deep is about 96 cubic feet, or 718 gallons. The liner endpoint sizes the flexible liner to fit a pond — length equals the pond length plus twice the maximum depth plus twice the overlap to anchor under the edging stones (same for width), so that same 8 × 6 pond at two feet deep with a one-foot overlap needs a 14 × 12 ft liner and matching underlayment. The stock endpoint turns a water volume into a safe fish load and the pump you need: roughly one koi per 250 gallons (they grow large and dirty) or one goldfish per 20, plus the pump flow in gallons per hour to turn the whole pond over at least once an hour for koi — 718 gallons holds about two koi and wants a ~720 GPH pump before head-height losses. Everything is computed locally and deterministically, so it is instant and private. Ideal for landscaping and pond-installer tools, garden-design and home-improvement apps, koi and water-garden hobbyist sites, and aquascaping calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. For pool chemistry use a pool API; for indoor fish tanks use an aquarium API.