---
title: "NPC Pro - Reviews, Revenue and Downloads in United States | Apple App Store"
description: "NPC Pro LSI Calculator & Startup Guide – The Ultimate Water Chemistry Tool for Pool Professionals!  Developed by the National Plasterers Council (NPC), the NPC Pro LSI Calculator & Startup Guide is th"
---

# NPC Pro — United States

![NPC Pro App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple221/v4/58/93/aa/5893aafd-7277-6250-c99d-7d84a1c7dba0/AppIcon-0-0-1x_U007emarketing-0-11-0-85-220.png/400x400bb.png)

**Developer:** [National Plasters Council](https://apptail.io/developer/national-plasters-council-gHXf)
**Category:** Business
**Rating:** 5.0/5 (1 ratings)
**Price:** Free
**Bundle ID:** npc.lsi-calc
**Store:** Apple App Store
**Country:** United States
**Version:** 2.1.1 (released 2026-02-15)
**Original Release:** 2017-09-04

**App Store Link:** [Download on Apple App Store](https://apps.apple.com/us/app/app/id1273077384)
**AppTail Page:** [https://apptail.io/app/npc-pro-kRZd/united-states](https://apptail.io/app/npc-pro-kRZd/united-states)

## NPC Pro Description
NPC Pro LSI Calculator & Startup Guide – The Ultimate Water Chemistry Tool for Pool Professionals!

Developed by the National Plasterers Council (NPC), the NPC Pro LSI Calculator & Startup Guide is the essential app for pool professionals, technicians, and service providers. Whether you’re calculating the Langelier Saturation Index (LSI) to ensure balanced water chemistry or following proper startup procedures for new plaster finishes, this app simplifies the process with accuracy and ease.

Key Features:

- LSI Calculator – Quickly determine water balance to prevent scaling, etching, and plaster degradation.
- Water Chemistry Guide – Get precise recommendations for pH, alkalinity, calcium hardness, and more.
- Startup Procedures – Follow NPC’s step-by-step plaster startup guide for long-lasting, durable finishes.
- Easy Data Input – Enter key pool chemistry values and get instant LSI results.
- Professional-Grade Accuracy – Designed for pool contractors, service techs, and water chemistry experts.
- User-Friendly Interface – Simplifies complex calculations for effortless use on the job.
- Ask The Expert – If you have questions we have answers, use our ask the expert form to get answers to your toughest questions from the NPC community experts.
- Connect. Engage. Explore. In addition to the tools, NPC Pro offers you access to find members, stream podcasts, access technical resources, connect with NPC social media and more. 
- Podcasts

Why Use the NPC Pro LSI Calculator & Guide?
Balanced water chemistry is crucial to maintaining a beautiful, durable swimming pool finish. The LSI Calculator ensures your water is within the ideal range, preventing costly repairs and extending the life of pool surfaces. The Startup Guide provides step-by-step instructions to correctly introduce new plaster finishes, avoiding common issues like discoloration or surface roughness.

Whether you’re a pool professional, service technician, or pool owner looking for precise water chemistry management, this app is your go-to tool!

Download the NPC Pro LSI Calculator & Startup Guide today and take the guesswork out of pool chemistry!

Pool Owners • Pool Professionals • Tech Resources • Education

Affiliations:

American Shotcrete Association
Independent Pool and Service Association
California Pool and Spa Association
The Association for Pool and Spa Professionals
American Concrete Institute
American National Standards Institute
Institute for Code Council

Our Mission
The National Plasterers Council will continue to be the utmost authority in the preparation, application, materials, start-ups and preservation of cementitious pool interior finishes. The NPC will collaborate with other associations and serve the industry through research, education, promotion, and certification of all segments of the pool industry including pool owners, the pool service providers, plasterers, manufacturers, specifiers, remodelers, architects, and builders.

## NPC Pro Screenshots
- [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/f1/33/37/f1333796-35b7-b8f2-40a7-74225a377736/01.png/2048x2732.png)
- [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/66/eb/31/66eb3133-c9ac-a5c6-dd76-64376b0ecb8a/02.png/2048x2732.png)
- [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/f3/b1/c6/f3b1c6c7-08b0-e19b-d661-f55190cb3b64/03.png/2048x2732.png)
- [Screenshot 4](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/ed/4f/13/ed4f1346-780a-5d87-8004-86b064a26645/04.png/2048x2732.png)
- [Screenshot 5](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/a8/fe/b9/a8feb9ae-20ba-e370-acbd-c9b59c86f9b1/05.png/2048x2732.png)
- [Screenshot 6](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/e9/f2/b3/e9f2b30d-9e25-809d-fe9f-9667ae8d3117/06.png/2048x2732.png)
- [Screenshot 7](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/d1/a4/af/d1a4af56-657a-de92-9226-2c581ee499ce/07.png/2048x2732.png)
- [Screenshot 8](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/72/49/44/724944c5-c0e0-81ac-a66c-2a54a4269ab0/08.png/2048x2732.png)
- [Screenshot 9](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/0c/22/47/0c224736-81f7-b52b-a32a-75a2255bb184/09.png/2048x2732.png)
- [Screenshot 10](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/e7/72/f9/e772f97e-f344-fae9-676b-91a468e10706/10.png/2048x2732.png)

## NPC Pro Rating Breakdown in United States
- 5 stars: 1 (100%)
- 4 stars: 0 (0%)
- 3 stars: 0 (0%)
- 2 stars: 0 (0%)
- 1 stars: 0 (0%)

## NPC Pro Reviews in United States

### *---- "Plagiarism of Orenda"
This app is clearly a copycat of Orenda, without giving them credit. Even the settings menu is identical in formatting and spelling. Blatant plagiarism. AND the math doesn’t align. 

It would be one thing if you gave credit to them (like PoolBrain does), but no. Seems like intellectual property theft to me.
-- Samstone135, 2025-06-16

### ***** "Great resource for all in swimming pool industry!"
This is such a great app and resource. LSI calculator, Start up instructions, NPC Technical Library and downloadable files & start up card. Get all the expertise of the National Plasterers Council at your fingertips with ease!
-- dreamyLJ99, 2025-02-25

### ***** "Great new app"
The new app that NPC just put out is really great. So many features. Thank you NPC. Love the calculator and podcasts.
-- ILScott1000, 2025-02-05

### ***-- "Not sure it’s accurate"
Not sure it’s accurate with lower alkalinity and higher PH levels at 50 ppm borate.  The LSI goes negative as the PH approaches 8.5 for my pool conditions of 80 ppm alkalinity, 290 CH, 50 ppm borate, 60 CYA, 86 Fahrenheit, 4500 tds.   Seems maybe the borate correction on alkalinity allows alkalinity to go negative at higher PH levels?  Is this correct?
-- Awesome SadieTank, 2022-07-04

### ***** "Great App"
I own a pool service company in AZ and I use this app all the time to get my LSI readings at each pool. Even though it doesn’t give you suggested amounts of chems to use to adjust the numbers that’s ok for now, although I’d like to see that calculator on here someday. It’s dead in accurate every time.
-- Trav2001, 2021-02-16

### *---- "Not for testing pools!"
This app is not designed to calculate any sort of pool treatment ( not like google recommends),  it only displays the end condition of your water chemistry based on the input values your give it.
It wides not tell you chemicals to add to bring your pool back to a (clear water) state.
-- Dr. Adjustment, 2020-09-01

### ***** "My bad."
App great
-- Merlin4900, 2019-02-06

### ***** "Now good to go on iOS 12"
With the latest update the app is working as advertised.  Back in business, thanks!  I will add that the arrow graphic at the top is pretty much unreadable with way too small fonts.  But the rest of the app is good.
-- Reme18MZ, 2018-10-23

### *---- "Doesn’t work on iPhone"
Input boxes are stacked on top of each other. Can’t use
-- hjsjfnekzknrjxjdwjj, 2018-10-03

[View all NPC Pro reviews and detailed analytics on AppTail](https://app.apptail.io/signup?utm_campaign=ai-crawl&utm_content=reviews)



## NPC Pro Discovered Keywords
- npc pro

## Apps Similar to NPC Pro
- [Intl. Pool/Spa/Patio/Deck Expo](https://apptail.io/app/intl-poolspapatiodeck-expo-YmA/united-states)
- [Pool Trader](https://apptail.io/app/pool-trader-Krhb/united-states)
- [LSI Calc DB Water Balance Log](https://apptail.io/app/lsi-calc-db-water-balance-log-rSZd/united-states)
- [LSI Calculator](https://apptail.io/app/lsi-calculator-EHce/united-states)
- [HASA water](https://apptail.io/app/hasa-water-dQSo/united-states)
- [Heritage Pool Plus](https://apptail.io/app/heritage-pool-plus-CpWq/united-states)
- [Clonio AI](https://apptail.io/app/clonio-ai-LMqr/united-states)
- [2025 Pool & Spa Show](https://apptail.io/app/2025-pool-spa-show-CsZt/united-states)
- [EUSExpo 2025](https://apptail.io/app/eusexpo-2025-ustv/united-states)

## NPC Pro Available In
- [United States](https://apptail.io/app/npc-pro-kRZd/united-states)
- [Brunei](https://apptail.io/app/npc-pro-kRZd/brunei)
- [Chile](https://apptail.io/app/npc-pro-kRZd/chile)
- [China](https://apptail.io/app/npc-pro-kRZd/china)
- [Germany](https://apptail.io/app/npc-pro-kRZd/germany)
- [Dominican Republic](https://apptail.io/app/npc-pro-kRZd/dominican-republic)
- [Ecuador](https://apptail.io/app/npc-pro-kRZd/ecuador)
- [Estonia](https://apptail.io/app/npc-pro-kRZd/estonia)
- [Hong Kong SAR China](https://apptail.io/app/npc-pro-kRZd/hong-kong)
- [Azerbaijan](https://apptail.io/app/npc-pro-kRZd/azerbaijan)
- [Israel](https://apptail.io/app/npc-pro-kRZd/israel)
- [South Korea](https://apptail.io/app/npc-pro-kRZd/south-korea)
- [Kuwait](https://apptail.io/app/npc-pro-kRZd/kuwait)
- [Kazakhstan](https://apptail.io/app/npc-pro-kRZd/kazakhstan)
- [Lebanon](https://apptail.io/app/npc-pro-kRZd/lebanon)
- [Mexico](https://apptail.io/app/npc-pro-kRZd/mexico)
- [Romania](https://apptail.io/app/npc-pro-kRZd/romania)
- [Ireland](https://apptail.io/app/npc-pro-kRZd/ireland)
- [Slovakia](https://apptail.io/app/npc-pro-kRZd/slovakia)

---

## About AppTail

[AppTail](https://apptail.io) is a mobile app intelligence platform providing app analytics, ASO (App Store Optimization) tools, keyword tracking, competitor analysis, revenue estimates, and review monitoring for iOS App Store apps. Track your app's performance, discover ranking keywords, monitor competitors, and analyze market trends.

- [Search Apps](https://apptail.io)
- [Top Charts](https://apptail.io/top-iphone-apps)
- [Sign Up for Full Access](https://app.apptail.io/signup?utm_campaign=ai-crawl&utm_content=footer)

*Data provided by [AppTail](https://apptail.io) - Mobile App Intelligence Platform*