Comparison

Pool Calc vs Orenda

Orenda's app is a free LSI and dosing calculator from a pool chemical company, backed by a lot of free training. Many pool pros keep it on their phone. Pool Calc does the dosing and water balance too, and adds a saved log for every pool, doses for any brand of chemical, and, on Plus or Pro, clients, a route and service reports.

Prices, features and ratings checked on 28 October 2026.
App Store rating as shown on 28 October 2026: 4.7 stars from 477 ratings on the US App Store.

The short answer

Orenda is an excellent free calculator with a lot of free education behind it, and its 4.7 rating shows it. Pool Calc is the better fit if you want the numbers to stay: a log and charts per pool for owners, and clients, visit history, reports and chemical costs for pros, with doses written for whatever brand you buy.

At a glance

From each app's own App Store page and website, checked on 28 October 2026. "Not listed" means we found no mention of it there, not that the feature is missing.
Feature	Pool Calc	Orenda
Price	Free for one pool; Plus or Pro for more	Free
Water balance index	Yes CSI gauge	Yes LSI
Borates in the balance	Yes	Yes Optional borate factor
Dose for a target reading	Yes Ordered plan for all readings at once	Yes Dosing calculator
Chemical choices	Yes Any brand, any strength	Yes Choice of chlorine and acid strengths
Expected readings after an addition	Yes	Yes Future alkalinity after acid
Saved test history per pool	Yes	Not listed
Charts	Yes	Not listed
Several pools saved	Yes Plus (5) or Pro (unlimited)	Not listed
Reminders	Yes	Not listed
Share results	Yes PDF and CSV export	Yes Email or text from the results page
Clients, route and service reports	Yes Plus and Pro	Not listed
Chemical cost per client	Yes Plus and Pro	Not listed
Training videos and courses	No	Yes Videos, Orenda Academy
Pool volume estimator	Yes From shape and size	Yes
Platforms	iPhone (iOS 18 or later)	iPhone, iPad, Apple silicon Mac; Android per Orenda

Pricing

Our app

Pool Calc

Free$0Every feature for one pool and its attached spa.
Plus$1.99 a month, $14.99 a year or $39.99 onceUp to 5 pools plus the pro tools. 1-week free trial on the yearly plan.
Pro$9.99 a month or $79.99 a yearUnlimited pools plus the pro tools. 1-month free trial on the yearly plan.

Prices on the App Store at launch. Pricing is per person, not per pool.

LSI and dosing calculator

Orenda

Orenda appFreeLSI and dosing calculator, pool volume estimator, videos and Orenda Academy content.

Free on the App Store. No in-app purchases listed.

Prices as listed on 28 October 2026. Source

Orenda costs nothing. Pool Calc costs nothing for one pool. The difference shows up when you want to keep records: a log per pool for an owner, or a client list, visit history and reports for a tech.

A log, not just a calculator

Orenda's listing describes a calculator: you enter the readings and get the result. Pool Calc keeps every test, dose and maintenance task in a log you can chart from 7 days to all time, with your target band and each chemical addition marked on the chart. For one pool that's free.

Any brand on your shelf

Orenda's app lets you switch between its listed chlorine strengths and acids. Pool Calc lets you add any product at the strength on its label, set your own scoop, and record the price you paid, so each dose shows what it costs.

Pro records Orenda reviewers ask for

A pool service provider with about 100 pools asked Orenda in 2023 for saved customer pool and dosage history, a field for chemical prices, and Chinese. Pool Calc Plus and Pro include clients, a visit log per pool, a one-screen stop, a PDF report with your logo, and chemical use and cost per client.

What Orenda Users Complain About

Paraphrased from public reviews. Each one links to where it was posted and gives the month it was written.

No saved customer history or prices. In a 2023 App Store review, a service provider asked for paid customer accounts with saved pool and dosage history, plus a field for chemical prices (App Store review, October 2023).

Pool Calc approach: each client has their own pools, visit history and readings. Container prices on the product shelf give the cost of each dose, and the Chemical use & cost screen totals it by client and month.
Hard for newcomers. A 2021 App Store reviewer said the app works best after Orenda Academy, doesn't steer new users to the lessons first, and that product bottles were hard to find, with no MSRP shown (App Store review, August 2021).

Pool Calc approach: every reading has a plain help page, the plan says what to add and in what order, and the "Inputs used" disclosure shows what each dose was based on.

When Orenda is the better choice

You want a free calculator and don't need to keep records in the app.
You use Orenda products or follow the Orenda LSI method and want its training in the same app.
You work on Android or want an iPad layout.
Your business software already has Orenda's calculator built in. Skimmer, for example, lists an LSI & Dosing Calculator powered by Orenda on one of its plans.

Questions people ask

Is the Orenda app free?

Yes. The App Store listed Orenda as free with no in-app purchases on 28 October 2026, and Orenda's own page calls it the free Orenda App.

Does the Orenda app save my test history?

Neither the App Store listing nor Orenda's app page we read on 28 October 2026 describes a saved test history or client list. A 2023 App Store reviewer who services about 100 pools asked for saved customer history as a paid feature. Pool Calc keeps a full log for every pool, free for one pool.

What is the difference between LSI and CSI?

Both are saturation indexes that tell you whether water tends to scale or etch plaster. Pool Calc shows CSI, the Calcite Saturation Index, which accounts for the effect of CYA and borates on alkalinity and for ionic strength. Orenda's app uses the LSI. The two usually point the same way; read each app's number against its own target range.

More comparisons

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References

Orenda is a trademark of its respective owner. Pool Calc is not affiliated with Orenda Technologies or Hasa, Inc. Information checked on 28 October 2026; prices and features change. Corrections: [email protected]