How To Lower POOL ALKALINITY with MURIATIC ACID | Swim University

How To Lower POOL ALKALINITY with MURIATIC ACID | Swim University

– High alkalinity can cause
damaging scale to form inside your pool’s circulation
system like your pool filter and your pool pump and your pool heater, and high alkalinity can also mean high pH. They tend to go hand in hand,
but adding muriatic acid to your pool can help
tame the wild alkalinity, the high alkalinity, the high pH. All you need is a bucket,
some safety precautions, and a step-by-step guide on
how to do it, so let’s dive in. (upbeat music) All right, quick disclaimer. When it comes to pool
care, I have to say this, everyone has a different way of doing it. The following information is
based on my personal experience in the pool industry plus
the research we’ve done here at Swim University, and if I
missed anything, I apologize, but just leave a comment. Also, we’re talking about
pool chemicals here, and when it comes to pool chemicals, safety first, people, safety first. We’re talking about chemical
resistant gloves and goggles. Not just having them, we
want you to wear them, and you can also use a
chemical-resistant apron. An apron, am I saying that right? Apron, apron, and that’ll
help protect your clothes and your skin. You know, also, it wouldn’t
be such a bad idea to get, you know, one of those bane masks. You know, like those gas
masks because the vapors, inhaling those vapors,
can also be damaging too, so if you’re gonna be
messing with pool chemicals, a mask would be super helpful, Batman. It’s my impression, I’m
not very good at them. All right, before we talk
about adding muriatic acid to your pool to lower
your alkalinity and pH, what is muriatic acid? What’s that sound? (suspenseful music) Nerd alert. Believe it or not, muriatic
acid can actually be found in the human stomach and it
goes by a different name as well which is hydrochloric acid. For this video, we’re just
gonna call it muriatic acid. Now, muriatic acid comes
in many different forms. When you are buying muriatic
acid you want to make sure that you get it at your local
pool store because it is a different formula, and
before we actually use it, just remember that alkalinity
and pH, with enough time, will come down on their own,
but you just don’t want them high for too long ’cause
high for too long can cause scaling, it can
make your pump run harder, your heater work harder, your
filter system work harder, and that can cause long
term damage, so we just want to make sure that the pH
and alkalinity are always in the correct range, but again
if you are just on the brink of getting into the right
area, if you just give it enough time, it’ll come down on its own, and you won’t need to go
messing with any acids. So when you’re lowering
alkalinity in your water, you’re also going to be lowering
pH, so if you have high pH, but normal alkalinity, you can
add an alkalinity decreaser or a pH decreaser, which
is sodium bisulfate, but if you add those things,
they’re gonna bring both down, so it’s a good idea to get
them both in the correct range and then bring them up or down together. We are about to add
muriatic acid to our pool to lower the alkalinity,
however, before you go and add any chemicals to
any pools, you want to test the water first to make
sure that you even have to add any chemicals to the pool. If you’re adding just chemicals
because you think the pH might be high, that’s
not a good enough reason. No, you’re gonna have to
test it, and you can test it in one of three ways. You can either use test strips
which are fairly inexpensive, you can get them at your local
pool store and you can just pull a sample, pool a sample,
I get it, I know I did. When you pull the sample from
your pool, then you can use the test strip and dip it
in, wait about 15 seconds, measure up to the colors
on the back of the bottle, and you will know if you
have high pH, low pH, high alkalinity, low alkalinity. The other way you can do it is
you can use a liquid test kit which tends to be a
little bit more accurate, but there’s a lot more involved
when it comes to testing or instead, you can take a
sample of your pool water and bring it into your local
pool store and have them test it for you, and at
that point, you’re already at the store so you can
pick up muriatic acid or sodium bisulfate, which
again is pH decrease. Now we just want to know
how much muriatic acid are we gonna need to bring it down? In order to do that, we
have an online calculator. Just go to this link at the bottom. You could type in the readings
that you get from your test and it’ll tell you
exactly how much to add. You can also refer to
our pool care handbook which has dosage charts. (upbeat music) Okay, this video is technically
sponsored by our very own product called the pool care
handbook and video course. You can get it by going to or you could just, here’s the URL here. This is our fully illustrated
eBook and video course teaching everything you need
to know about taking care of your swimming pool, whether
you’re new to owning a pool or you’ve been doing this for a while. It’s a great resource you
can always check back in and you can watch the
entire course and get a huge crash course on taking
care of your swimming pool. (upbeat music) We know we need to add
muriatic acid to the pool, so we know how much muriatic
acid we need to add to the pool so how do we add muriatic
acid to the pool? Do we just poor it in? Do we just get the jug and
just poor all willy nilly, splashing it around? Of course not, we’re smarter
than that, we’re intelligent. What we’re gonna do to add
muriatic acid is we’re gonna add 10 parts of water to
one part muriatic acid and that is how we’re gonna dilute it, and what we’re gonna do is
we’re gonna add these 10 parts of water to a bucket first,
just a bucket of water, 10 parts and then we’re gonna add
one part of muriatic acid to that bucket of water
and we’re not gonna do it the other way around
because the other way around can cause splashing into our,
hopefully, protected face with the goggles and
the mask and the gloves, and then we’re gonna take a
paint stirrer and we’re gonna slowly mix the muriatic
acid and the water together and then we are gonna slowly
poor that muriatic acid dilution solution into
our pool and then finally, you’ve added the chemical, you’ve done it, did your pH come down? I will wait about an
hour, maybe even more, maybe the next day, and
retest your water the same way you tested it the first time,
whether it’s with test strips or liquid test kits or you
brought it into your local pool store, whichever that
way was, that’s your base, get it retested the exact same
way so that you know your pH and alkalinity actually came down. If I missed anything,
again leave a message in the comments letting me know. I could do an update for
sure, and if you have any more questions, please go
to That’s it, happy swimming. (upbeat music)

10 thoughts on “How To Lower POOL ALKALINITY with MURIATIC ACID | Swim University

  1. Diluting the acid in a bucket prior to adding to the pool is not necessary, as adding the acid into thousands of gallons of pool water is dilution enough

  2. I was at 170, I added 3 GALLONS of muriatic acid and now I am only down 10 to 160. 25,000 gallons, no heater. Just got water tested by pool store, they said to add 1.5 QUARTS! What's that going to do when 3 gallons did so little?

  3. My pool has high alkalinity and low ph. I live in Michigan and our water has high alkalinity from limestone. How it it even possible to have high alkalinity and low ph? I’m so confused.

  4. Hello! Thanks for all the informational videos. I’m having a problem. I have a vinyl above ground. I was able to get my ph up by using baking soda and borax, and once it was 7.4 I shocked it. And I have floater with 3 chlorine tabs and a chlorine tab in my filter. 1 hour after shock the chlorine was great last night. But this morning it plummeted. And is at .5 again. What can I do to keep the chlorine ideal. The ph dropped to 7.2 this morning as well.

  5. My pool is about 27,000 gallons. Last test showed pH at about 7.6 and alkalinity around 190 PPM. Can you give me a ballpark figure to start with as far as how much acid to add to get the alkalinity in range?

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