API · /aquarium-api

Aquarium Calculator API

healthy 4,856 Subscribers

Aquarium maths as an API, computed locally and deterministically. The volume endpoint computes a tank's water volume — in US and UK gallons and litres — for a rectangular, cube, cylinder, hexagonal or bow-front tank from its dimensions (inches by default, or centimetres, millimetres and metres), and applies a fill factor (default 0.9) for substrate, decoration and freeboard to give a realistic net volume. The stocking endpoint gives a rough stocking load from the tank volume and the total length of fish using the classic inch-per-gallon guideline, reporting the maximum recommended inches and how heavily stocked the tank is. The waterchange endpoint computes the water-change volume for a percentage, with an optional dechlorinator dose. Everything is computed locally and deterministically, so it is instant and private. Stocking is a rough beginner guideline only — real stocking depends on the species, filtration and bioload. Ideal for aquarium and fishkeeping apps, pet-shop and hobbyist tools, and tank-setup planners. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is aquarium maths; for swimming-pool volume and chemical dosing use a pool API and for storage-tank gauging use a tank API.

#aquarium #fish-tank #volume #stocking #aquascaping #developer-tools

api.oanor.com/aquarium-api

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Machine-readable spec so AI agents can integrate this API.

/api/aquarium-api/openapi.json

/api/aquarium-api/llms.txt

Discovery: GET /api/index.json lists every API.

API health

healthy

Uptime: 100.00%; Server probes · 24h
Avg latency: 92 ms; Server probes · 24h
Subscribers: 4,856; active
Total calls: 40; last 7 days

Full status page → · 20 probes/24h

Pricing

Pick a tier — billed monthly, cancel anytime.

Free

12,635 calls / month
2 requests / second
Hard cap (429 above quota, no overage)
12,635 calls/month
2 req/sec
Volume + stocking + water change
No credit card

Starter

€14.15 /month

22,250 calls / month
8 requests / second
Hard cap (429 above quota, no overage)
22.25k calls/month
8 req/sec
5 tank shapes, metric/imperial
Email support

Pro

€34.05 /month

272,500 calls / month
20 requests / second
Hard cap (429 above quota, no overage)
272.5k calls/month
20 req/sec
Aquarium / hobby pipelines
Priority support

Mega

€72.05 /month

1,405,000 calls / month
50 requests / second
Hard cap (429 above quota, no overage)
1.405M calls/month
50 req/sec
Platform scale
Dedicated SLA

Built by

PremiumApi

Related APIs

Other APIs with overlapping tags.

Aquascape API

Planted-aquarium and aquascaping maths as an API, computed locally and deterministically — the dosing and water numbers a high-tech planted tank runs on, not the rolls of a dice. The co2 endpoint gives the dissolved CO2 concentration from pH and carbonate hardness using the classic relationship CO2 (ppm) ≈ 3 × KH (dKH) × 10^(7 − pH), and flags it against the 15–30 ppm window plants want — at pH 6.6 and KH 4 you are at about 30 ppm, the top of the safe zone, while pH 7.0 and KH 3 is a carbon-limited 9 ppm. The fertilizer endpoint turns a dry-salt dose into the nutrient ppm it adds, the heart of Estimative Index dosing: ppm = grams × the nutrient mass fraction × 1000 ÷ tank litres, so 1 g of KNO3 in 100 litres adds 6.1 ppm nitrate and 3.9 ppm potassium, and it knows KNO3, KH2PO4, K2SO4, MgSO4 (Epsom) and Ca(NO3)2. The substrate endpoint sizes the substrate from the footprint and target depth — a 60 × 30 cm tank at 6 cm deep needs 10.8 litres, two 9-litre aquasoil bags. Everything is computed locally and deterministically, so it is instant and private. Ideal for aquascaping and planted-tank apps, fertiliser-dosing calculators, CO2-rig tools, and aquarium-shop and hobby sites. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. For a tank water volume or fish stocking use an aquarium API; for pool chemistry use a pool API.

api.oanor.com/aquascape-api

Water Turnover API

Water turnover and circulation maths as an API, computed locally and deterministically — the flow-rate numbers a pool tech or aquarist sizes a pump to. The turnover endpoint relates a body of water's volume to its flow: turnover time = volume ÷ flow rate, and turnovers per day = 24 ÷ turnover time, so a 50,000-litre pool circulated at 10,000 L/h turns over in 5 hours, almost 5 times a day (pools usually target an 8–12 hour turnover, 2–4 a day); give a target turnover time instead and it returns the flow rate to size the pump to. The aquarium endpoint accounts for the real-world head loss that robs a pump of flow: effective flow = rated flow × (1 − head loss), so a 1,500 L/h pump at 40 % loss really moves 900 L/h, about 4.5× a 200-litre tank an hour; give a target turnovers-per-hour (freshwater 4–6×, planted 5–10×, reef 10×+) and it returns the rated pump to buy so losses still leave enough flow. Everything is computed locally and deterministically, so it is instant and private. Ideal for pool-service, aquarium, hydroponics, water-feature and pond app developers, pump-sizing and circulation tools, and equipment education. Pure local computation — no key, no third-party service, instant. Use consistent volume and flow units. Live, nothing stored. 2 compute endpoints. For pump power and head use a pump API; for pool chemistry a pool-chemistry API.

api.oanor.com/turnover-api

Tank Volume API

Tank volume and fill-level maths as an API, computed locally and deterministically. The volume endpoint gives the total capacity — in litres, US gallons and cubic metres — of a vertical cylinder, horizontal cylinder, rectangular tank, sphere or capsule, from its dimensions in metres, centimetres, millimetres, feet or inches. The fill endpoint computes the volume of liquid and the percent full at a given fill depth, using the exact geometry for each shape — including the circular-segment formula for a horizontal cylinder (where the level is famously non-linear) and the spherical-cap formula for a sphere. The level endpoint is the inverse "dipstick" calculation: it finds the depth that corresponds to a target volume or a target percentage, solving the segment geometry by bisection. Everything is computed locally and deterministically, so it is instant and private. Ideal for fuel, water, oil and chemical tank monitoring, agriculture and irrigation, process and industrial tooling, and tank-gauging and dipstick apps. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is tank-gauging geometry; for swimming-pool volume and chemical dosing use a pool API, and for plain unit conversion use a unit-conversion API.

api.oanor.com/tank-api

Geometry API

Calculate the geometry of common shapes. Get the area of 2D shapes (circle, square, rectangle, triangle — by base/height or three sides via Heron, trapezoid, parallelogram, rhombus, ellipse, regular polygon), the perimeter or circumference, and for 3D shapes the volume and surface area (sphere, cube, box, cylinder, cone, square pyramid). Pass a shape and its dimensions and get back the exact result plus the formula used. Pure local math — no key, no third-party service, instant and deterministic. Live. 6 endpoints. Built for CAD and engineering tools, education and e-learning, construction and material estimation, and any app that needs reliable shape math. Distinct from a generic expression evaluator or unit converter.

api.oanor.com/geometry-api

Frequently asked questions

Quick answers about pricing, quotas, and integration.

How do I get an API key for Aquarium Calculator API?

Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Aquarium Calculator API with the x-oanor-key header. No credit card needed for the free tier.

What's the rate limit for Aquarium Calculator API?

Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.

How much does Aquarium Calculator API cost?

Aquarium Calculator API has a free tier with 100 calls / month. Paid plans start at €14.15 / month with higher quotas and faster rate limits.

Can I cancel my subscription anytime?

Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.

Is Aquarium Calculator API GDPR-compliant?

All requests to Aquarium Calculator API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.

Aquarium 3

Meta 1

Pick an endpoint from the list on the left to see its details and try it.

GET /v1/stocking

Stocking estimate

Playground

Parameters

Custom headers

Language: Client:

GET /v1/volume

Tank water volume

Playground

Parameters

Custom headers

Language: Client:

GET /v1/waterchange

Water change volume

Playground

Parameters

Custom headers

Language: Client:

GET /v1/meta

Spec

Playground

Custom headers

Language: Client:

Code snippets

curl https://api.oanor.com/aquarium-api/SOME_PATH \
  -H "x-oanor-key: oanor_test_..."

const res = await fetch("https://api.oanor.com/aquarium-api/SOME_PATH", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();

$ch = curl_init("https://api.oanor.com/aquarium-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);

import requests
r = requests.get(
    "https://api.oanor.com/aquarium-api/SOME_PATH",
    headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())

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Aquarium Calculator API

API health

Pricing

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Related APIs

Aquascape API

Water Turnover API

Tank Volume API

Geometry API

Frequently asked questions

Parameters

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