This tool provides a general estimate and does not replace professional veterinary advice.
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What is the Koi pH Dosing Calculator?
The Koi pH Dosing Calculator calculates how much pH adjuster to add safely to koi tanks. Water quality is the single biggest factor in aquatic animal health. Far more animals are lost to poor water parameters than to disease introduced from outside.
A well-cared-for koi usually lives somewhere between 25 and 40 years. As an omnivore, what a koi needs from its diet changes across its life stages. Koi are pond fish, not aquarium fish. They need a minimum of roughly 3800 liters, at least 1.2m depth for overwintering, and heavy biological filtration to cope with their waste output. The usual suspects for this species are koi herpes virus, ulcers and bacterial infections, anchor worm and fish lice, so any noticeable change is worth following up.
Koi temperature and humidity chart
| Zone | Target |
|---|---|
| Cool end | 59–65 °F (15–19 °C) |
| Warm end | 65–73 °F (19–23 °C) |
| Basking spot | 73–77 °F (23–25 °C) |
| Night-time | 52–64 °F (11–18 °C) |
How does the Koi pH Dosing Calculator work?
The figures are based on commonly cited aquarist rules of thumb and safe parameter ranges for koi, scaled to your tank or livestock details. Treat the result as a well-founded estimate. Every koi is an individual, and your vet's judgement outranks any online tool.
What changes the answer
- Tank size and current stocking level
- Filtration capacity: which affects how much waste the system can safely process
- Feeding habits: since overfeeding is a leading cause of poor water quality
- Source water quality before treatment, which varies by location
How do you use the Koi pH Dosing Calculator?
- Enter the current pH
- Enter the tank volume in whichever unit you use (US gal, L, UK gal)
- Answer "How did you test?"
- Press Calculate, then read the result alongside the sources listed below
Worth doing: jot down the date and the result each time. A single number tells you little, but a trend across a few months tells you a lot about your koi.
For related questions, see the other water tools or browse every koi tool.
Before you rely on this
Averages hide a lot of variation. The figure here reflects what is typical for koi, but your koi may sit well outside it for perfectly ordinary reasons. Use the result to spot changes over time in your own animal rather than to compare it against other people's pets.
Sources and references
The formulas, reference ranges and species data behind the Koi pH Dosing Calculator come from these veterinary references, professional bodies and published research.
- University of Florida IFAS ExtensionAquacultureedis.ifas.ufl.edu(opens in a new tab)
- Merck Veterinary ManualReptilesmerckvetmanual.com(opens in a new tab)
- ARAVAssociation of Reptilian and Amphibian Veterinariansarav.org(opens in a new tab)
- Merck Veterinary ManualExotic and Laboratory Animalsmerckvetmanual.com(opens in a new tab)
- Merck Veterinary ManualRoutine Care and Breedingmerckvetmanual.com(opens in a new tab)
- Built on veterinary referencesFormulas and ranges come from veterinary manuals, university research and welfare bodies, listed above for you to check.
- Instant resultsNo page reload, no waiting and no account. Enter your details and the result appears straight away.
- Private by designCalculations run in your browser. Nothing you enter is stored on our servers or shared with anyone.
- Always freeEvery XpertsPet tool is free to use, with no premium tier and nothing to sign up for.