# NPC Pro vs E

The clearest difference is update cadence: E at every 4 months against NPC Pro's every 24 months. On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

NPC Pro ships an update every 24 months, E every 4 months. The most recent releases landed on October 10, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | NPC Pro | E |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.0 (3 ratings)](https://appshunter.io/ios/app/e-z-clor-pool-care/id6739361010/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 24 months | **Every 4 months** |
| Monetization | Free | Free |
| Size | 84 MB | 57 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [National Plasters Council, Inc](https://appshunter.io/developer/1273077383) | [Pool Corporation](https://appshunter.io/developer/508083385) |

## What reviewers say

### NPC Pro

[App page](https://appshunter.io/ios/app/npc-pro/id1273077384)

This app helps pool professionals manage water chemistry and follow startup procedures for plaster finishes. It offers an LSI calculator, water chemistry recommendations, and step-by-step guides for maintaining pool surfaces. Connect with experts and access resources to ensure balanced water and durable finishes.

**Highlights:** LSI Calculator for water balance, Water chemistry recommendations, Plaster startup procedures guide, Easy data input for instant results, Professional-grade accuracy, Ask the Expert feature, Access to podcasts and technical resources

**Features:** macOS Compatibility

**In-app purchases:** none


### E

[App page](https://appshunter.io/ios/app/e-z-clor-pool-care/id6739361010)

This app analyzes pool water by taking a photo of test strips. It provides detailed results and recommends specific chemicals needed to balance your pool's water chemistry.

**Highlights:** Photo-based water analysis, 5-Way Test Strip compatibility, Detailed water chemistry results, Chemical balancing recommendations, Free to use

**In-app purchases:** none


## Frequently asked questions

### Is NPC Pro free?

NPC Pro is free to download, with no in-app purchases.

### Is E free?

E is free to download, with no in-app purchases.

### Do NPC Pro or E have ads?

Neither NPC Pro nor E shows ads.

### Which is updated more often, NPC Pro or E?

NPC Pro ships an update every 24 months, and E every 4 months. Most recently, NPC Pro was updated on October 10, 2026 and E on October 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*