Pool salt calculator
Saltwater swimming pools and salt-chlorine generators need a stable sodium chloride concentration, usually a few thousand parts per million, before the cell can make chlorine and the water feels right on the skin.
Run — free
Homeowners topping a winter-diluted basin, builders filling a new shell, and service routes all face the same arithmetic: given the basin volume in liters, the salinity you measure today, and the target the manufacturer printed on the cell, how many kilograms of pool salt must go in. This pool salt calculator applies the closed-form mass balance that one part per million is one milligram of salt per liter, so the add-mass in kilograms is volume times the salinity gap divided by one million. It refuses a target that is not strictly above the current reading, because dilution—not more salt—is the path when you overshoot. The free browser widget and the API share one pure function, so a patio estimate matches the work-order line a script posts later.
How to use it
Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.
Check your inputs
Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.
Use it again or automate it
Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.
What you can do with it
Get an answer now
Enter one set of values and see the result without building a spreadsheet or script.
Compare scenarios
Change one value at a time and rerun the calculation to understand what affects the result.
Automate repeated work
Use the API when the same calculation needs to run inside your product or workflow.
FAQ
How do I use this capability?
Complete the fields above and run it on this page. The form highlights anything that needs attention.
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/life/pool-salt \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"volume":50000,"current_salinity":2500,"target_salinity":3200}'const res = await fetch("https://api.kit.forhosting.com/life/pool-salt", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"volume": 50000,
"current_salinity": 2500,
"target_salinity": 3200
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/life/pool-salt",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"volume": 50000,
"current_salinity": 2500,
"target_salinity": 3200
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/life/pool-salt", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"volume":50000,"current_salinity":2500,"target_salinity":3200}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"volume":50000,"current_salinity":2500,"target_salinity":3200}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/life/pool-salt", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"volume": 50000,
"current_salinity": 2500,
"target_salinity": 3200
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "life.pool_salt",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |