From Newsgroup: comp.mobile.android

PSA: Best free no-registration no-ads outdoor-pool-chemistry calculator app
For Windows, iOS & Android
No advertising (except they may suggest their own chemicals)

Just some myths that are perpetuated by lack of chemistry knowledge...
a. "1-3 ppm FC is ideal" -> False once CYA exists in an outdoor pool
b. "Shock weekly" -> Unnecessary if FC:CYA is maintained correctly
c. "Algaecide/phosphate-remover prevents algae" -> False; FC:CYA does
d. "Stabilizer should be 30-50 ppm" -> False; FC should be ~7.5% of CYA
e. "pH must be 7.2-7.6" -> False; pH has almost no effect on sanitation
f. "TA must be 100-120" -> False; LSI/CSI is what matters
g. "CH must be high to protect plaster" -> False; LSI/CSI is what matters
h. Low pH causes itchy eyes -> False; chloramines cause itchy eyes
i. Too much chlorine has that YMCA smell -> False; chloramines do that
j. Add acid to counteract bleach high pH -> False; it self-balances in hours
k. FC is the best measurement of sanitation -> False; ORP is
l. Trichlor "pucks" are great -> False; they raise CYA & lower HOCl over time m. TDS is an important measurement -> False; it's mostly a measure of water age n. "High CH causes scale" -> False; CSI determines scale, not CH alone.
o. Filtration is mandatory -> (debatable); I never run my pumps & my water is fine
p. Pump mixing is mandatory -> Not with bulk mixing from wind, temp, motion, density
q. Any other myths?

Swimming season is coming up (at least here in California), and what I've found, over the years, is this is the only known pool calculator app that is
a. Free
b. Registration free
c. No ads (although every calculator suggests their own chemicals)

Web:
<https://www.orendatech.com/pool-dosing-calculator>
Android:
<https://play.google.com/store/apps/details?id=com.elitecrest.orenda>
iOS:
<https://apps.apple.com/us/app/orenda/id1171005221>

It's not just the individual calculations that matter, but what matters is almost every pool-chemistry advice on the web is dead wrong in many ways.

There are only two calculators on the planet, that I am aware of, which are correct, and one of those requires you to log into their web site. Having
said that, both provide free online advice, which is kind of nice of them.

This TFP calculator is also correct, but it requires registration (AFAIK).

Web:
<The old 'PoolMath Web' calculator is gone; replaced by PoolMath Pro>
Android:
<https://play.google.com/store/apps/details?id=com.troublefreepool.poolmath> iOS:
<https://apps.apple.com/us/app/pool-math-by-troublefreepool/id1228819359>

As far as I'm aware, no other pool calculators available to the public are correct.
But I could be wrong, so please let us all know if you know of better calculators.
--
Free your pool from bad advice given what matters is sanitation & saturation. --- Synchronet 3.21d-Linux NewsLink 1.2

From Newsgroup: comp.mobile.android

Maria Sophia wrote on 3/6/2026 6:15 AM:

PSA: Best free no-registration no-ads outdoor-pool-chemistry calculator app
��� For Windows, iOS & Android
��� No advertising (except they may suggest their own chemicals)

Just some myths that are perpetuated by lack of chemistry knowledge...
a. "1-3 ppm FC is ideal" -> False once CYA exists in an outdoor pool
b. "Shock weekly" -> Unnecessary if FC:CYA is maintained correctly
c. "Algaecide/phosphate-remover prevents algae" -> False; FC:CYA does
d. "Stabilizer should be 30-50 ppm" -> False; FC should be ~7.5% of CYA
e. "pH must be 7.2-7.6" -> False; pH has almost no effect on sanitation
f. "TA must be 100-120" -> False; LSI/CSI is what matters
g. "CH must be high to protect plaster" -> False; LSI/CSI is what matters
h. Low pH causes itchy eyes -> False; chloramines cause itchy eyes
i. Too much chlorine has that YMCA smell -> False; chloramines do that
j. Add acid to counteract bleach high pH -> False; it self-balances in
hours
k. FC is the best measurement of sanitation -> False; ORP is
l. Trichlor "pucks" are great -> False; they raise CYA & lower HOCl over time
m. TDS is an important measurement -> False; it's mostly a measure of
water age
n. "High CH causes scale" -> False; CSI determines scale, not CH alone.
o. Filtration is mandatory -> (debatable); I never run my pumps & my
water is fine
p. Pump mixing is mandatory -> Not with bulk mixing from wind, temp,
motion, density
q. Any other myths?
Swimming season is coming up (at least here in California), and what
I've found, over the years, is this is the only known pool calculator
app that is a. Free
b. Registration free c. No ads (although every calculator suggests their
own chemicals)

Web:
<https://www.orendatech.com/pool-dosing-calculator>
Android: <https://play.google.com/store/apps/details?id=com.elitecrest.orenda>
iOS:
<https://apps.apple.com/us/app/orenda/id1171005221>

It's not just the individual calculations that matter, but what matters
is almost every pool-chemistry advice on the web is dead wrong in many
ways.

There are only two calculators on the planet, that I am aware of, which
are correct, and one of those requires you to log into their web site. Having said that, both provide free online advice, which is kind of nice
of them.
This TFP calculator is also correct, but it requires registration (AFAIK).

Web:
<The old 'PoolMath Web' calculator is gone; replaced by PoolMath Pro> Android: <https://play.google.com/store/apps/details?id=com.troublefreepool.poolmath>

iOS: <https://apps.apple.com/us/app/pool-math-by-troublefreepool/id1228819359>

As far as I'm aware, no other pool calculators available to the public
are correct.
But I could be wrong, so please let us all know if you know of better calculators.

Thanks. Maybe you should do a tutorial on the subject?


--- Synchronet 3.21d-Linux NewsLink 1.2

From Newsgroup: comp.mobile.android

To continue to add on-topic value for online/app pool calculators, it's important to note that almost all pool advice on the web is for "indoor"
pools, whose chemistry is *completely different* than outdoor pools.

Since most residential pool owners have an outdoor pool, this thread topic
is only about the correct chemistry calculators for those outdoor pools.

For those on this newsgroup who have outdoor pools (keeping in mind almost everything any pool store or pool professional ever told you about pool chemistry is likely wrong), it's worth noting that only two outfits on the Internet (that I'm aware of) have any semblance of what's correct about
pool chemistry, which are Orenda/Hasa and TroubleFreePool (both of whom
have calculators which are essentially equivalent in terms of utility).

Since the Orenda/Hasa calculator doesn't require an account, I use it most:
<https://hasa.com/pool-chemical-calculator>

But the TroubleFreePool web site also provides scientifically valid advice:
<https://www.troublefreepool.com/blog/poolmath/>
Although TFP seems to have dismantled their online pool-math calculator:
<https://www.troublefreepool.com/blog/poolmath/>
Since everyone has a phone nowadays, their web version died (AFAIK).
<https://www.troublefreepool.com/threads/pool-math-online-calculator-vs-pool-math-app.232558/>

Here's a summary of what you need to know to maintain your outdoor pool for
i. Sanitation
ii. Saturation

A. Core chemistry a complete pool calculator must include

1. Saturation balance (LSI)
a. pH
b. Temperature
c. Total alkalinity
d. Calcium hardness
e. TDS
f. LSI interpretation (corrosive, balanced, scaling)

2. Sanitation and disinfection
a. Free chlorine
b. Combined chlorine
c. Cyanuric acid (CYA)
d. FC/CYA ratio guidance
e. Shock or SLAM calculations
f. Chlorine demand estimation

3. Water balance adjustments
a. Acid and base dosing
b. Raising or lowering TA
c. Raising or lowering CH
d. Salt additions
e. Borates
f. Evaporation and refill effects

B. Important features that pool owners need to understand include

1. Dynamic LSI modeling
a. LSI at current temperature
b. LSI at peak summer temperature
c. LSI at heater temperature
d. LSI drift as pH rises naturally

2. CO2 off-gassing and pH rise prediction
a. Expected pH rise rate
b. Effect of aeration
c. Acid required to counter natural drift

3. Calcium carbonate precipitation modeling
a. When CaCO3 will precipitate
b. How much will precipitate
c. Effect of temperature and CO2 loss
d. How LSI changes as dust dissolves or forms

4. Dilution and refill modeling
a. Refill volume
b. Refill chemistry (TA, CH, pH)
c. Evaporation rate
d. Splash-out and backwash losses
e. Resulting chemistry after mixing

5. Filter loading and cleaning intervals
a. Estimated particulate load
b. Pressure rise prediction
c. Cartridge cleaning or backwash timing

6. Seasonal chemistry planning
a. Winter LSI targets
b. Summer LSI targets
c. Heater-safe ranges
d. Plaster-safe startup curves

7. Chlorine production modeling for SWG pools
a. Output vs temperature
b. Runtime needed to maintain FC
c. Cell scaling risk based on LSI

8. Troubleshooting modules
a. Cloudy water
b. Scaling
c. Etching
d. Algae risk
e. High chlorine demand
f. Linking symptoms to chemistry causes

Overall, almost everything you hear from the likes of the swimming-pool bloggers on the net is likely dead wrong based on my experience and
knowledge of chemistry (which most people who own pools don't have).
<https://bloggers.feedspot.com/swimming_pool_blogs>
--
Only one in a million people truly understand heavily marketed products.
That's because very few people have the background to question the myths.
--- Synchronet 3.21d-Linux NewsLink 1.2