15,000-Gallon Pond: Pump, Filter & Stocking Guide
Every key number for a 15,000-gallon pond in one place: a 15,000 GPH pump, a 220W UV clarifier, about 60 koi, 8 aeration diffusers, and 375.3 lb of salt at 0.3%.
Quick answer
A 15,000-gallon pond wants a pump near 15,000 GPH (buy rated ~19,500), a 220W UV clarifier in partial sun, about 60 koi or 300 goldfish, 8 aeration diffusers, and about 375.3 lb of pond salt for a 0.3% treatment. Tap any number below for the full breakdown.
15,000-gallon pond: every number
| Question | Answer |
|---|---|
| Pump flow (koi, once/hour) | 15,000 GPH (buy ~19,500) |
| UV clarifier (partial sun) | 220W |
| Koi stocking | ~60 koi |
| Goldfish stocking | ~300 goldfish |
| Aeration diffusers | 8 (Commercial air pump) |
| Pond salt at 0.3% | 375.3 lb |
This is the one-page system summary for a 15,000-gallon pond. Each figure below is computed from the same formulas in our calculators, and each links to a full answer with the table, context, and gear. At this volume the pond meets the usual koi minimum, given a deep zone of at least 3 feet.
How the Numbers Fit Together
Circulation comes first: a pump near 15,000 GPH turns a 15,000-gallon koi pond over once an hour, and you buy one rated around 19,500 GPH to beat head and plumbing losses. A 220W UV clarifier polishes out green water, while 8 diffusers on a commercial-class air pump keep oxygen up. Stocking stays conservative at about 60 koi or 300 goldfish, because overstocking is the root of most water-quality trouble. Pond salt, when needed, runs about 375.3 lb for a 0.3% treatment.
Open Any Answer for the Full Breakdown
Each linked page below shows the computed number, a short table, the reasoning, and matched gear for a 15,000-gallon pond. Start with circulation and filtration, confirm your stocking, then layer in aeration and any salt treatment. If you are still planning the build, the pond volume calculator confirms your true gallons first, and the liner calculator sizes your EPDM and underlayment.
Core gear for a 15,000-gallon pond
The heart of your circulation.
Clears and prevents green water.
Track ammonia, nitrite, and pH.
Run your own numbers or keep exploring:
Pond Build & Maintenance Planner
Build planner, stocking planner, water-test log, and seasonal maintenance schedule, in one printable planner that keeps your pond healthy year-round.
Frequently Asked Questions
What pump and UV does a 15,000-gallon pond need?
Plan for a pump near 15,000 GPH (buy one rated around 19,500 GPH for head losses) and a 220-watt UV clarifier in partial sun. Both scale with your gallons, and full sun bumps the UV size up.
How many fish can a 15,000-gallon pond hold?
About 60 mature koi at 250 gallons each, or about 300 goldfish at 50 gallons each. This pond meets the 1,000-gallon koi minimum given a 3-foot deep zone.
How much aeration and salt for a 15,000-gallon pond?
Run about 8 diffusers on a commercial-class air pump, hardest in summer. For a 0.3% salt treatment, add about 375.3 pounds of pure pond salt, gradually and predissolved.
Planning or running a pond?
Use our free calculators and guides to get every number right.
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