I opened my pool last week and went to get my pool water tested today. I
did not believe the results so I went right home got 2 more samples and went
to 2 other pool places to see what they thought.
My Pool - 23,000gal Gunite/Plaster
Here are the results:
Before I went I took my own tests:
Total Chlor: 3
Free Chlor: 3
1st place I went:
Saturation index: -1.5
Total Chlor: 1.4
Free Chlor: 1.4
Demand Drops: 10
Tot. Alkalinity: 56
Adj. Alkalinity: 26
They took the test and said your alkalinity is 26 you need to add 50lb of
alkalinity up. Since I had just tested my self I did not believe the
results. Besides this being low the wanted me to bring it up to 125
minimum. This is strange to me too as I have always been told 80-120 for my
plaster pool. I questioned them and they stuck to their guns. After I left
I noticed on the sheet they had something called Adjusted Alkalinity which
is much lower than Alkalinity - I don't know where this adjusted value comes
from but it was too late to ask. They use a system called "alex" by
2nd Place I went:
Total Chlor: 3.0
Free Chlor: 3.0
Total Alkalinity: 80
Total Hardness: 250
They said my water was perfect - don't do a thing. They agreed that the alk
should be in the 80-120 range.
3rd place I went:
Total Chlor: 2.0
Free Chlor: 2.0
Total Alkalinity: 90
Total Hardness: 170
My own results seem to be more in line with the last two places. How could
there be such a difference in opinion on pH, Alkalinity, CYA, and hardness?
Does the first place not know what they are doing or do they know something
that the other do not know? I'm leaning tword the former.
Let me know what you think.
Accurate and reliable testing is very expensive. It simply isn't
available with methods like your home kit or the in-store testing. We
may naively want to believe it works, but the cold truth is that it
can't be trusted.
Most likely: (1) The first place is dangerously incompetent. (2) The
others are just using colorimetric tests like you do at home, and these
are necessarily very crude to start with, and often spoiled. Given the
unknown condition of the reagents and the vagaries of reading subtle
color changes in unknown light by uncritical persons, the figures agree
within the expected error. This error is so large as to make the
figures useless for anything but very crude prescriptions.
The water testing is just a gimmick to get you into the store and to
sell you stuff. Your results how unreliable and inaccurate it can be,
to the point of being utterly untrustworthy.
You have to do your own testing and learn to do it reliably. I like the
big Pool Time test kits; they come (or used to) with coupons for several
years of free annual refills via mail to keep the reagents fresh and
If you want to do testing right, see http://www.hach.com/ and
> They took the test and said your alkalinity is 26 you
> need to add 50lb of alkalinity up. Since I had just
> tested my self I did not believe the results. Besides
> this being low the wanted me to bring it up to 125
> minimum. This is strange to me too as I have always
> been told 80-120 for my plaster pool. I questioned them
> and they stuck to their guns. After I left I noticed on
> the sheet they had something called Adjusted Alkalinity
> which is much lower than Alkalinity - I don't know where
> this adjusted value comes from but it was too late to
> ask. They use a system called "alex" by Bioguard.
I believe Adjusted Alkalinity refers to the idea that the
cyanuric acid stabilizer in the water tests as alkalinity,
but doesn't behave that way with respect to scaling or
corrosion. They make an adjustment to remove the "false"
part of the alkalinity.
This is a controversial interpretation, and in my experience
since 1979, it just doesn't work in practice. The
alkalinity test in my Taylor kit produces results which seem
to work fine without making any adjustment. In other words,
I keep the unadjusted TA within the 80-100 range, and over
the years have had no scaling or corrosion. Also, pH tends
to be stable in that range.
If I add the large amounts of sodium bicarbonate which would
be called for by the adjusted number, it just makes the pH
spike, and I end up having to add acid every day to bring it
back down. Then when the ph has stabilized, I measure TA
and find the unadjusted value to be 80-100. So in my
experience, the whole exercise just encourages sales of
bicarb, then acid, only to leave you right where you
If Alkalinity Up is really bicarb, as I suspect, then their
recommended addition of 50 lbs is just silly. That would be
40 lbs in my 18.6K gallon pool, which is 10 big boxes of Arm
& Hammer baking soda. If you really needed that, I think
you would already be experiencing severe corrosion problems.
The other reading from store #1 that seems out of line is
the CYA measurement. Even with Richard's warning about the
accuracy of these tests, I don't see how they could get a
CYA reading that is essentially double what the other stores
If I were in your shoes, I would not let store #1 measure my
water in the future. It appears that all of their errors
(if that's what they are) tend to produce larger sales of
chemicals to you. Of course, that could be incompetence.
Sure it could.
:If I add the large amounts of sodium bicarbonate which would
:be called for by the adjusted number, it just makes the pH
:spike, and I end up having to add acid every day to bring it
:back down. Then when the ph has stabilized, I measure TA
:and find the unadjusted value to be 80-100. So in my
:experience, the whole exercise just encourages sales of
:bicarb, then acid, only to leave you right where you
I too have been down that full circle . But I'd like to add
a different slant to this problem of inconsistant values from
one dealer's test to another.
Last night I shaved and splashed cologne on. A few minutes
later I submerged my water bottle for the pool chemical test.
The pH reading was way off from the day before. What was
happening was the blue cap that covers the kit so it can be
shaken was being contamenated when I touched it. It's happened
before so it wasn't difficult to figure out.
Cigarette fingers will contamenate the water too. So with this in
mind, water for testing could be tainted by the pool owner or by
the dealer's help, like in the case of smokers.
I suppose if your water gets tested by someone just coming off
from a smoke break it could very well be quite different than
your own test (unless you smoke too :)
I have found that the "free" water checking at most pool stores is
completely unreliable. For example, yesterday I took a sample in and
got a chlorine of 5.0 which they said was only as far as their scale
goes so it was probably more. I used test strips and a chem test kit
to check it myself and gor 2.0 on each. Another example: I can take
samples in daily and the hardness result comes out somewhere between
250 and 400. The 250 and 400 were on consecutive days. The next day
they got 320.
These places think (and do) hire just anyone can test. Evidently they
are wrong. Get the right chemical tests kit and do it yourself.
Nothing is really "free".
On 12 Jul 2004 06:48:52 -0700, email@example.com (Lex)
It's a basic taylor kit sold by leslie's
It only checks chlorine and ph but does so well. I used to have a
cheaper kit (brand-x) which works almost the same. Used it for a few
years but was never happy with the colors on the glass that you have
to match with your water. The taylor is better for sure. For all other
tests (like stabilizer) I have an older kit which I really never use.
I take a sample to leslie's and have them do it (maybe 3 times a
year). I see them do it and know they do it correct. I have never had
ANY problems. I only add chlorine and acid, that's it. Never had
algae, never had cloudy water. Never had green hair or other
discoloring/smelly water. This is in Arizona and in July the water
goes up into the 90's , and if there's a place that algae likes to
grow in it's in 90+ degree water. Never had algae.
Best way to maintain a pool is test it regularly for ph and chlorine
and keep those two up. I test it about once a week, sometimes I skip a
week (depends also on usage). In winter I check less since there's not
much chance of algae and the chlorine stays in the water much longer.
good luck. Pool maintenance is easy.
Remove NO-SPAM from email address when replying
I just wanted to offer my thoughts for what ever they may be worth.
work at a pool store owned by my grandparents. This is there 25th yea
in business and I have been there 13 years of it. We are from a smal
area they call us a maw & paw store but the business is growing b
leaps and bounds we have in excess of 1000 customers which might not b
lot to some but around here it is a lot! Anyways I agree with the on
who says a lot of pool stores hire just anybody to work inside, som
do, the other pool store around here hires a lot of high school girl
to run the water test, they run it on the computer read the result
(not knowing what they mean) and sell you the chemical to fix th
problem. There is 2 problems with that: 1) the person hasn't a clu
what they are telling you & 2) the computer program is meant to sel
the chemicals. For insist in you alk is 50 & the safe ranges o
chlorine is for it to be 80 to 120, the computer is going to sell yo
the max to get you to the 120 mark, that way when you come in next the
will have to sell you something to lower the alk. that where th
experience counts, our pool store has 4 main girls in the office and w
have all been there at least the 13 years all the way up to the 2
years, we do have a couple other girls who answer the phone, show th
pools, and can even run the pool test but then passes it on to one o
us who has been there longer. We also have the computer programing bu
we don't use the computer part (the parts that tell us what you shoul
do) we run the water in on our labs UDV in that means anything t
anybody & we know what to tell them with out the computer, we woul
sell you the least amount to get you into the safe range. I know som
of you doubt what I am saying but it is true, if you are not happy wit
us you may not come back and you definetly won't tell anybody about us
the the other pool store went bankrupt last year I think we are doing
good job. But anyways if you were to come into our store for say & w
came up with that reading you got in pool store #1, & if you told u
that isn't what you got, we would have reran the test (the vials can b
wrong) we would probably have check it with strips too and if we wer
still off that much we would told you to do nothing bring in anothe
sample in a few days & if possible bring your tester so we could se
what was going on. I personally think that is nuts telling you to ad
50lb of increaser, I don't ever recall selling that much to anybod
even with ones with 0 alk. I know we have sold 24 lb before but the i
the largest amount I ever remember & that isn't to often. We do offe
the free water test for anybody that buys their chemicals thru us, eac
test runs us $10 to run and they can come in once a day, once a week o
as often as they need to be comfortable with their pool and I am no
saying they have to buy each time they come just over all buy thei
chemicals from us because there are plenty of times people don't nee
anything or have it at home. We just usually say to bring in you
water once a month to get it tested so the things that can't be teste
at home are checked, I know some test check the alk but some don't & i
the alk is truely low & not corrected in can pull plastcides out of you
liner & cause pin holes. I am truely sorry for those of you who don'
offer a good honest pool store. We strive hard to be one. Good luc
to all and sorry I rambled on & on!
jlangdon's Profile: http://www.homeplot.com/member.php?useridView this thread: http://www.homeplot.com/showthread.php?t#77
That seems to be the main thrust of all in store pool testing. I never
use as much chemical as they tell me on the first dose. It is a lot
better to work up to the right level than to slam in a bunch and
overshoot. Most of the time they tell me my water is OK but they still
have some magic potion I could use to make it "better".
Anyone with a pool should get the 5 bottle kit (as a minimum) and
learn how to use it. Those strips are pretty much useless.
I recently bought a house with an in ground pool, I did know a pool
had a filter, pumps, water and ate some amount of Chlorine other than that
I was lost. But after about 6 months I have got it under control. Most
people said get a pool service. In my area the rate is about $60 to $75 a
month and that's just to check the water and put chemicals in. One thing I
found right off is find a decent pool supply that actually try's to help
you. I went to the big pool chain store ( I don't want to say there name but
there initials are L E S L I E 'S) they always had something I had to have.
I do test my own water and also have the pool store test it. There some
things you realy can't test yourself.
No, the stips are not useless: They are a good, cheap
interim check for your pool, though NOT a replacement
for a good testing kit. Eventually you catch onto the
nuances, and the strips save money if you're testing
correctly and on the right schedule. ANYONE that's
surprised by anyhting in or about his pool isn't paying
close enough attention to it.
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