More Rookie Pool Chemistry Mistakes Pt.2 – Bob Lowry

Think a four-hour pump schedule is “good enough”? We put that myth to rest with clear math, real-world examples, and a simple plan for dialing in filtration so you stop chasing cloudy water and recurring algae. With Bob Lowry in the chair, we unpack why three turnovers is the sweet spot for clarity and safety, how to measure true flow instead of guessing, and what happens to sanitizer when circulation goes quiet for twenty hours a day.

We also get honest about bather load. A backyard pool can hit zero free chlorine minutes after seven adults or a pack of energetic kids jump in. That’s not scare talk—it’s demand math. We walk through why “keep chlorine low” backfires in stabilized pools, how cyanuric acid changes your targets, and the exact pre-party and post-party steps to protect swimmers and keep callbacks off your weekend. You’ll hear practical guidance on variable-speed settings, placing a flow meter, and setting run times around gallons per minute, not habit.

Training ties it all together. Quick seminars often isolate one idea—like higher CYA—without showing the trade-offs for pH control and chlorine strength. We share why full-scope chemistry education builds confidence, speeds decisions on route, and helps you explain choices to cost-sensitive homeowners with data they can trust. You’ll learn where to find live and online pool chemistry certification, how to access technical bulletins, and how to turn testing-first into a repeatable, profitable workflow.

• three turnovers as the target for clarity and safety
• how to calculate turnover using actual flow rate
• circulation’s role in stopping biofilm and algae
• bather load math that crashes free chlorine
• why “keep chlorine low” is bad advice with CYA
• simple pre-party and post-party dosing plans
• full-course training versus one-hour seminars
• where to find certifications and tech bulletins
• daily workflow: test first, then dose with purpose

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Episode Transcript

SPEAKER_00 (01:02):
Hey, welcome to the Pool Guy Podcast Show.
It is best of Bob Lowry.
We're going to continue our talkin part two of some rookie
chemistry mistakes.
And again, Bob Lowry is going tounpack some common mistakes you
can make out there that cost youtime and money on your pool
route.
So I hope you enjoy this talkwith Bob Lowry on some typical

(01:22):
rookie chemistry mistakes.
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(01:44):
Another thing that we've touchedon before is, you know,
homeowners may not know thisbecause they always are trying
to cut their runtime down ontheir pool filter.
That's one of the problems Ihave out there, is they're
always telling me I just had acustomer yesterday tell me, oh,
can you reset my system so it'snot running so long because my
electricity bill was super high.
But I think runtime of runtimeof the pool filtration system is

(02:08):
one thing that new people don'treally pay attention to.
You know, they may get anaccount where the customer has a
20,000-gallon pool running forfour hours a day and they're
scratching their head, you know,why is the pool cloudy?
Why is there algae?
So the runtime is a big deal,especially in the season.

SPEAKER_01 (02:24):
Yeah, it you know, the the fact of the matter is
that that from a filtrationstandpoint, if if you get one
turnover of the pool, and aturnover is an amount of water
that's equal to the volumethat's in the pool gone through

(02:46):
the filter.
So um, and so it's based onwater flow.
So if you take the the gallonsin the pool and divide it by the
flow rate, then you will findout what your turnover is in
minutes, um, assuming that yourpump is in gallons per minute.
So you can determine how manyminutes or hours it is to get

(03:10):
one turnover.
But from a a filtrationstandpoint, one turnover will
only give you about 65%filtration.
And then if you get twoturnovers, it will give you
about 85% filtration.

(03:33):
And three turnovers will get youabout ninety-two to ninety-five
percent, and four turnovers willget you ninety-eight or
ninety-nine percent.
So what we recommend is that youget three turnovers because the

(03:55):
difference between threeturnovers and four turnovers is
like three percent, it's notworth doing, but you need to get
three turnovers in your pool,and you can calculate for
yourself how many minutes that'sgonna be, and all you need to
know is the flow rate.
And so you put a uh a rotameteror flow valve uh right after the

(04:19):
pump, uh, right after um I'msorry, at least after the pump
and and before it gets back tothe pool to find out what your
flow rate is, and and then allyou have to do is do the math.
You know, if you got 20 gallonsor 30 gallons a minute running
through there, you got a 15,000gallon pool.

(04:41):
How many minutes is that?
You know, it's 500 minutes toget one turnover.
And and 500 minutes is uh almosteight hours.
You know, so so and if you wantthree turnovers, it's 24 hours.
So if you if you only run yourpump at 30 gallons a minute for

(05:04):
four hours, that's not even oneturnover.
That's a half a turnover.
So you can't possibly get getenough uh filtration to to have
a great looking pool.
The other thing is if the if youonly run your pump for four
hours a day, that means for 20hours a day, there's no

(05:27):
circulation.
And and if you have a biomass, abiofilm, or an algae starting to
grow someplace, it the thatmass, that biomass uses up the
chlorine that's in the vicinity.
And if the circulation pump'snot on, it used up all the

(05:49):
chlorine.
Now it can grow like crazybecause there's no new sanitizer
being brought to that area ofthe pool because there's no
circulation.

SPEAKER_00 (06:00):
Yeah, and I think that's key.
You know, the circulation issomething that people don't pay
too much attention to whenthey're starting, and it's a key
factor for sure.
Um, another thing I think thatnew people don't understand is
the high bather load and how itaffects the pool.
I know we talked a little bitabout that with the Airbnb um
segment, but high bather loadreally affects the pool,

(06:24):
residential pool, especially,because they're first of all,
they're not as big as acommercial pool per se, in most
cases.
So a commercial pool has, youknow, 30,000, 40,000 gallons or
more, and you have a little10,000 gallon pool back there,
and you have eight or ten kidsin there.
Um the high bather load, howdoes that affect the water
chemistry in a pool itself?

SPEAKER_01 (06:45):
Well, um, the biggest thing is that the
chlorine level goes to zeroquickly.
We hear this from homeowners allthe time.
I need to keep a low chlorinelevel in my pool.
And I, you know, I respond withall kinds of answers to that
because that's just wrong.
You know, keeping a low chlorinelevel is is a terrible idea.

(07:07):
Um, first of all, you gotcyanuric acid in the pool, and
that's preventing you fromgetting in touch with very much
chlorine anyway.
And you should tell that to yourhomeowners that that there's
only three percent of thechlorine that you're being
exposed to.
So it's practically nothing.
Um and secondly, the an adultbather has a a chlorine demand

(07:33):
of four grams of chlorine eacheach one.
And so I did the math some timeago and uh in response to a
question I got from someone.
And the fact of the matter is ina 15,000 gallon pool, once you
put in 7.3 people, if you hadtwo parts per million of

(07:58):
chlorine in the pool, it's nowzero.
Okay, so if you put in 10 kids,um I'm not sure, it depends on
the kids, I'm sure, but I'm notsure whether an adult is equal
to a kid or a kid's actuallyequal to more, because I have a

(08:18):
feeling that kids actually peein the pool more than more than
adults do.
Um but uh uh in any case maybeten kids is equal to seven
adults.
So the minute you put ten kidsin the pool, you're out of
chlorine.
And and if it's a one call aweek, how long's it gonna be?

(09:02):
How long does that bacteria fromthose kids have to multiply and
and thrive in that pool till youget back and put some chlorine
in it?
You know, that's that's thething that you need to think
about.
The number one thing that youare charged with as a as a
service guy is to provide safewater.

(09:24):
And and if you ask a homeowner,they just did a survey.
The number one thing that peoplewant is safe water.
So you're supposed to providesafe water.
How are you gonna provide safewater if if 10 minutes after
after 10 kids get in the pool,there isn't any chlorine?
How are you gonna do that?

SPEAKER_00 (09:47):
Yeah, and so I think the key for that is um, you
know, even as a new pool serviceprovider, communication with the
customer.
Nowadays you can text cust theycan text you, and I would let
the customer know, hey, look, ifyou're having a pool party, let
us know ahead of time so we canprepare for it.
And we may be able to leave you,you know, a gallon of liquid,
whatever we can leave you afterthe party to pour in.

(10:10):
And I think that's the key isthe understanding that you just
can't go through your day andtreat every pool the same
because some pools, of course,no one ever uses them.
That's you know, one of thethings you run into.
But then there are those poolswhere they're using them all
summer long.
I mean, I've I've been back ataccounts before where I go back
there at eight in the morningand there's already kids in the
pool.

(10:30):
Yeah.
So it's one of those things thatyou just have to be aware of
that that affects it.
And I think the last thing we'lltouch on here is the importance
of proper training.
And you have a certifiedresidential course that you do
on Saturdays uh once a month,roughly, and you also they also
teach that at the pool shows.
And I think one thing that newpeople don't realize or don't

(10:52):
understand is the importance ofgetting educated, getting
trained getting training.
You know, if you go to a poolshow, though these rooms should
be full of everyone in there,but usually they're half full,
most of the courses.
And I think the importance ofeducation and continue education
is important because you've evensaid new things come on, the

(11:12):
industry that you weren't awareof in the past, and they're you
have to kind of be up on it.
And your tech bulletins are agreat way of getting that out
there.
And I just read the one on PHyou put out there, and I think
you know, being educated andlearning new things and and
realizing that things change alot in the industry, um, and
just learning the basics, youknow, is really important.

SPEAKER_01 (11:34):
Well, there really is isn't anything that's out
there that's a whole course.
And that's why we developed thethe the pool chemistry uh uh
course that we did, um, becauseyou can go read an article, you
can go to a seminar and stuff,but most of those are on a
subject, or they're just theyjust they have one hour to

(11:58):
discuss pool chemistry, and theyjust say, keep your pool in
these ranges, have a nice day.
And and you know, you're stillleft with, how do I do that?
I would just say, get educated,learn what you're doing.
If you attend a seminar,recognize that the guy is just
talking about one subject.
And what we try to do is we putit all together so that you

(12:21):
understand that if you go to aseminar and some guy says, it's
okay to keep cyanuric acidhigher, you know, he doesn't
tell you what it's gonna do topH and what it's gonna do to how
much chlorine you're gonna needin the pool.
You know, all he's doing issaying it's not gonna hurt your
plaster or something.
So recognize that listening to asubject is not the same as

(12:44):
listening to a whole course.
And and you really should thesedays listen to a whole course so
that you know what you're doing.

SPEAKER_00 (12:53):
Yeah, and I think your your particular course, I
took it uh several months ago.
You go over the gambit, you goover what water is, you know,
basically you start at the basicand you work your way up.
And a lot of things that wecover in these podcasts, you
cover in the class and they getcertified.
So they get, you know,certification, they get a patch,

(13:14):
they get a a little thing theycan hang.
And I think it's important tohave that certification and the
education, uh, more so yourclass over the CPO.
Not that CPO is not necessary,especially if we're doing
commercial accounts, but I thinkthe CPO course does not focus on
the chemistry like your coursedoes.

SPEAKER_01 (13:32):
Well, and I used to be a CPO instructor, and I can
tell you that the the number ofpages on chemistry in the CPO
manual is about 50 pages.
And the book that I wrote thatgoes with the course is 228
pages of chemistry.
And then we also have a secondbook that's 28 pages.

(13:54):
So we have 250 pages of poolchemistry.
And and CPO has 50.
You know, I often joke and sayif you want to know how to clean
toilets, take a CPO course.
You know, if you want to knowpool chemistry, come to our
course.

SPEAKER_00 (14:11):
Yeah, and I'll definitely give a plug for your
the course at the end of the ofthe uh uh podcast.
In fact, I'll do that in all thepodcast episodes so people can
find the course.

SPEAKER_01 (14:20):
Yeah, we do have some that are in person.
I'll be giving a course probablyat the pool industry expo in
Sept in September.
Um, and we just finalized thatlike yesterday.
Okay.
Um and we I will probably begiving a course at after the
Dallas show, the Pool Expo in inDallas.

(14:42):
We're probably going to give aclass on Friday after the show.

SPEAKER_00 (14:45):
Okay.

SPEAKER_01 (14:46):
Um in person.
Um and I may give one at theAtlantic City show in uh late
January.
Got it.
Yeah, so the instructors will begiving them online and in
person, you know, whenever theywhenever they want to.
Um and we now have six activeinstructors that are teaching

(15:09):
the the uh pool chemistrycertification course.

SPEAKER_00 (15:13):
Yeah, and they can find that easily by going to
your website uh pctti.online,and then you have the courses
there.
They can also sign up for yourtech bulletins.
Um there'll be a pop-up when yougo there.
And I recommend you sign up foruh Bob's tech bulletins.
They come in about quarterly, isthat about right?

SPEAKER_01 (15:30):
Um, I try to do one a month, but it seems like
they're getting farther apartthese days.

SPEAKER_00 (15:34):
You're pretty busy.

SPEAKER_01 (15:35):
But there are 15 tech bulletins on the website
that are free that you can lookat online or even download as a
PDF.

SPEAKER_00 (15:46):
Well, again, I thank you for the time with all the
content here.
And I think again, the educationI think is a key.
And then learning as much as youcan about what you're doing out
there is the key to success.
In any industry, you know,whether auto mechanic or
computer programmer, the moreyou know, the better you're
gonna be at your job, and thebetter you're gonna serve your

(16:06):
customers and and the betteryou're gonna be at your
business.
I think the confidence thatbeing educated gives you is the
key.
And, you know, people say, oh,you don't need a college degree
because you know you can makemore money without it.
But with that said, at least acollege degree gives you that
confidence that you have thatknowledge base.
And the same in the poolindustry, the more courses you

(16:28):
take, the more education youget, the more confident you're
gonna be out there servicingthose pools.

SPEAKER_01 (16:35):
Chemistry is something you use every day in
every pool.
And and understanding thechemicals and the chemistry are
what you're making your livingfrom.
The rest is just maintenance.
Anybody could do.
You could teach somebody how to,you know, how to check the
filter pressure and clean theskimmer basket and the pump

(16:55):
strainer basket, how to brush itand vacuum it.
You can teach them how to dothat in a in two days.
You know, the rest of it isunderstanding the chemistry, but
you use it every day.
What's the first thing you dowhen you go to the pool?
Take a water sample and andmeasure the measure the things
that are in the water and thenstart adding chemicals.
You need to understand.

SPEAKER_00 (17:15):
If you're looking for the podcast, you can go to
my website, swimming forlearning.com, on the podcast, on
the banner is a podcast icon.
Click on that, and there'll be adrop down menu with over
eighteen hundred podcasts foryou there.
And if you're interested in thecoaching program that I offer,
you can learn more atPoolGuyCoaching.com.
Thanks for listening to thispodcast.
Have a good rest of your week.
God bless.