A common question we get is how do you maintain a salt water pool? Or, what is the ideal water chemistry for
saltwater pools? We'll talk about the most important things to know about salt pool maintenance and the
top ten
most important chemistry levels for pools with saltwater chlorine generators .
Is the water chemistry different for saltwater pools versus traditional chlorine pools? The
basic
answer is no, there is just the salinity level of the water which is added to the mix. Water
chemistry
maintenance is typically easier with a salt pool, since your chlorine level (which is
what
usually would fluctuate the quickest) is maintained and the salinity level of the water remains fairly
constant.
Below are the top ten chemistry levels for saltwater pools, they are based on national standards and
although it
might not touch on every last thing there is to know, it will give you a pretty great start.
1. Free Chlorine
What it is - Free Chlorine (FC) is the leftover residual of sanitizer that keeps your pool clean and safe to
swim in.
If chlorine is added to the pool and you don't measure any FC, that means that there are enough
impurities that
the added chlorine has been completely used up and there wasn't enough leftover to create the measurable
residual.
Why it is important - A constant level of FC means that there is active sanitizer "waiting around" in the
pool, ready
to attack impurities as they enter the water. If your FC doesn't stay in range, that means that
impurities like
bacteria and algae can get a head-start on you and begin to grow and multiply in the water. FC is
consumed not
only by those impurities, but by the sun as well. Basically what that means that the FC is constantly
being
consumed unless more and more chlorine is being added to the pool (Which is what salt systems do for
you. Nice!)
.
Ideal levels - The ideal FC level varies, especially with your CYA level, but in general you want to keep
your FC
between 1-3 ppm in a saltwater pool.
2. Salinity
What it is - Salinity is how much salt is present compared to how much water is present, or in other words,
the level
of salt in the water.
Why it is important - Salt itself is not a sanitizer. Salt pool systems need a certain level of salt in the
water to
be able to operate and create chlorine. When salt levels are too low (and for some systems, too high),
the
process of generating chlorine is much less efficient and it puts much more strain and wear-and-tear on
the
chlorine generator's cell. Remember that salt doesn't get used up in the process. You only need to add
more salt
because you have drained water out of the pool or you have gotten a lot of rain (adding water for
evaporation
doesn't count). Since its levels don't naturally go down, remember to test, double-check, and add salt
in
batches so you don't add too much.
Ideal levels - Check your system's manual, but for most systems the ideal salinity range is right between
3000 - 3500
ppm.
3. Acidity / pH
What it is - pH is the balance of whether the pool is acidic or basic.
Why it is important - An imbalanced pH has pretty far-reaching repercussions. You chlorine will be less
effective,
requiring higher levels of chlorine being added to the pool. The water can become much more harsh on
your skin
and eyes. Imbalanced pH can even lead to damage to your pool itself and equipment. With experience,
you'll see
how your pool's pH wants to trend, and maintaining the pH can even become rather infrequent.
Ideal levels - pH levels typically want to be kept between 7.5 and 7.8 on the scale. Remember that small
changes on
the pH scale can add up to large results.
4. Stabilizer / Cyanuric Acid
What it is - Cyanuric Acid (CYA) is a conditioner chemical that helps prevent the sunlight from breaking down
chlorine in the water.
Why it is important - CYA is often called "sunscreen" for your chlorine. It is very important to have CYA in
your
pool water. However, as CYA "coats" the chlorine, it also begins to make the chlorine a less effective
sanitizer. That means it is also very important that you don't have too much CYA in your pool water. It
is also
important to know that CYA does not break down, which means that if you add too much, the only way to
lower the
CYA level is to drain large amounts of water from your pool to compensate.
Ideal levels - If you don't have an extremely high amount of sunlight, CYA is typically kept between 30 and
50 ppm.
With high levels of direct sunlight, CYA is typically kept as high as 70 and 80 ppm.
5. Phosphates
What it is - Phosphates are, unfortunately, very common substances that accumulate in pools and other bodies
of
water. They come from both natural and man-made sources. A very concentrated source of phosphates is
fertilizer,
however it is also a persistent part of our environment as well.
Why it is important - Phosphates create an EXTREMELY high chlorine demand in the water. Since phosphates
don't break
down naturally, the problem will only get worse until it is treated. High phosphate levels could
potentially
raise the chlorine demand of the water past the ability to add enough chlorine to compensate. Phosphates
also
allow algae to grow even with chlorine in the water.
Ideal levels - IDEALLY ZERO if possible, otherwise as far under 100 ppb (parts per BILLION) as possible.
6. Total Alkalinity
What it is - Total Alkalinity (TA) is the pool water's ability to "buffer" pH changes, or in other words, to
make it
easier or harder for pH to change.
Why it is important - TA balance can cause you need to use a larger quantity of a chemical to change the pH,
or allow
there to be rapid swings of pH. TA also determines the LSI which helps prevent pool damage or calcium
scaling.
Ideal Levels - Typical TA levels fall within 100-200 ppm.
7. Calcium Hardness
What it is - Simple enough, Calcium Hardness (CH) is the level of calcium based minerals in the pool water.
Why it is important - Imbalanced CH can lead to corrosion or damage to plaster or concrete, and excessive
scale
deposits.
Ideal Levels - It may vary with your pool type, but in general 200 - 400 ppm.
8. Saturation Index
What it is - The Saturation Index (SI) is the measure of the water's tendency to become corrosive or scale
forming.
Why it is important - the SI balance takes into account other chemistry levels such as pH, CH, TA and more. A
low SI
means that the water wants to absorb things into it and causes corrosion damage. A high SI means that
the water
wants to deposit things out of it and causes high levels of mineral scaling.
Ideal levels - The SI is kept between -0.2 to +0.2. The SI is measured on a small scale, with a one point
difference
indicating an effect in reality being 10x as severe.
9. Nitrates
What it is - Nitrates, like phosphates, are a powerful food source for algae. Nitrates, however, are not as
common in
pools, unless introduced through fertilizer-based sources.
Why it is important - Nitrates cause very high chlorine demand in the pool water, don't break down naturally,
and
can't effectively be treated. Significant nitrate levels in the pool require it to be drained.
Ideal levels - Zero if possible
10. Other contaminants
What it is - Contaminants such as metals (copper, iron, etc...) and ammonia
Why it is important - These contaminants can make it harder to balance your other chemistry levels, cause
high
chlorine demand, and even stain pool surfaces.
Ideal levels - Zero
TIP: Check your chemistry levels frequently when you first install a saltwater chlorine generator. With
experience,
you'll find out the way your pool water tends to behave, and fairly quickly discover that your chemical
maintenance needs have been greatly, greatly reduced.
Converting your pool to salt just means adding a chlorine generator! Use our intelligent
product
recommendation system to see what the best choices for you might be. See
more now ►
Comments (0)
Add CommentBRIAN D RUTLEDGE
What chlorinator would be best? Could I use normal Salt water treatment chemicals Cyanuric acid, Muriatic acid and Algeacide etc..?
DSP Staff
Brian, You typically want a salt chlorinator that can handle at least 50% more gallons than your pool holds. You initially just add regular pool salt or water softener salt (Sodium Chloride) to start up when you install the system, and you'll balance all of your other supplementary water chemistry as normal, like you mention - nothing else changes or requires special chemicals.
Michael Sheehan
Test strip shows low chlorine level in pool. We are only running the chlorine generator at 25%. If we raise it to 50% will that raise the chlorine level.