how reliable is store water testing?

amieelynne

Active member
Jun 5, 2007
33
Massachusetts
#1
so..a week into this and we still haven't gone swimming yet :cry: between the issues I had with the filter, cool days and now chemical readings I just want to cry

yesterday I took some water to my local store and they spit out these readings:

my pool (their rec. #)
TC 0 (1-3)
FC 0 (1-3)
pH 8.2 (7.4-7.6)
original TA (what's that??) 60
adjusted TA 49 (110-180)
hardness 60 (130-300)
cya 36 (35-100)

now this is after I dumped in 2 gal of bleach 4 hours before pulling the water...so it must have all burnt off--but I don't get how I already have a cya of 36 when I haven't added anything to the pool. they tried to get me to buy tons of stuff, of course, but I didn't. I had some pool chems at home that came with the pool and figured I would use that and BBB to see if I could straighten this out. put in 16lbs of pH down (they had rec 27lb) last night. added 1.5 gal of bleach this morning--tested this afternoon (after work) and according to my HTH 5 my water is

chlor 0
TA 80
pH 7.5

so...I threw in a gal of liquid shock that came with the pool (it said to use 1/2 gal for 10,000gal water), threw 2 pucks of slo poke tabs in in-line chlorinator and set to 3. but nothing else

what's the deal...is the pool store off that much or is my home test kit? where did the cya come from if I didn't add any stabilizer and just tonight added pucks? what else should I do now so hopefully we can swim tomorrow, weather permitting?
 

RavenNS

Active member
Apr 13, 2007
29
Canada
#2
Is the pool water 100% fresh? perhaps CYA was left over from last season?

as for Pool Store testings... well, let me tell you a little story.

I had three different Pool Stores test my pool within a 24 hr period.
as well as Testing by a friend with his kit,
testing with two different types of "guess-strips"
and testing with an electronic meter that I have.

Every single testing result from each source is different from one another!!! :shock:

I think at some point you just have to "go with your gut", when that happens.
( well, that my opinion anyway.. and it seems to be working )
 
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amieelynne

Active member
Jun 5, 2007
33
Massachusetts
#3
it's a brand new pool, so it's water straight from my hose--city water not well. my neighbor 2 houses down had to do a new liner in her pool this year..so a complete refill with hers. she took a water sample to the store and they said that her iron was very high...claimed that our city water was high in iron (had never heard that before) and got her to buy a bunch of stuff to get rid of metals. I was worried that I would have high iron reading too...I mean, we live next to each other--both filled off city water within the same week--right? nope--no iron in my readings...go figure, maybe they had overstock of that metal stuff? :roll:

can't figure the cya though--is that in normal water, or could that be a false reading too--that is the one test I didn't re-do myself. I just retested the chlorine and got a 2.5
 

Buggsw

LifeTime Supporter
Apr 22, 2007
925
Arizona
#5
Not all pool stores are bad, though.

There are a lot of variables that can affect readings.

The best thing you can ever do for yourself is to get a good test kit and learn how to use it. At first you may be clumsy and nervous about it, but once you learn, it takes 5 to 10 minutes at most to do a complete set of tests. Only a couple of minutes to do a chlorine & pH test daily.

If you start out right and chart your readings, time of day, water temp, etc. You start to learn the personality of your pool. Though it really is recommended to test daily, once you know your pool you may be able to test ever other day or every couple of days. It's so quick to do, though, so I rarely skip a day. I even do use the test strips for a super quick check on some days. I found a brand I trust pretty well, but I like playing chemist and try to use the drop tests most days.
 
G
#6
chem geek said:
There won't be any CYA in tap water or even well water.
Actually the herbacide atrazine does break down into CYA among other things and runoff from it can contaminate well water.
In areas where the herbacide is used it is possible for CYA to be present in the ground water.
 

momof2grlz

LifeTime Supporter
#7
I think the best investment you can make is a good test kit. And the most difficult adjustment you'll make is . . . learning to trust your results. Test the water yourself and post your results here. You'll get great advice and all the help you need to get your water balanced. And the best thing about help from this forum is that no one is trying to sell you chemicals to increase their store's profit margin. The people at the pool store don't have some magic computer that tests your water. They do the tests just like you can do at home. If 3 different employees run the tests on the same water sample, my guess is you'll get 3 different results.

Here's an example of something that happened to me. I had our water tested 4 weeks ago at the "L" pool store. I was checking for salt content and don't have a test for salt yet. The young girl said my CYA was 50 - right where I want it. 2 weeks ago, a new "L" store opened closer to my home. Since I had just done a stain treatment, I figured I'd take my water to the new store for testing. Guess what? According to the new store's employee my CYA had dropped to 0 over a 2 week period and I needed to buy a 4 lb. tub of CYA immediately. When I questioned him about where my CYA went over a 2 week period since CYA isn't highly consumable (and he found out that his sister store had provided my latest CYA reading), he started to back peddle and said "Oh, well let's wait then - maybe today's test was just a fluke". Sorry, but I think CYA was the chemical they were pushing that day.

I've also had the same dire warnings about my phoshate readings (300). When I let them know I'm not interested in PhosFree since I keep my chlorine level up and it's a fiberglass pool, they start to stammer and give me their line about an algae-free warranty if I use the PhosFree products. I just tell them no thanks.

Read everything you can find on this forum about testing and balancing your pool yourself. You'll be so much better off than putting yourself through the agony of being "pool stored".

Chris
 

DaveNJ

LifeTime Supporter
May 22, 2007
520
Toms River, NJ
#8
My test kit verses to pool stores. I had never had the pool water tested by anyone other than myself before. Just did it to see what the differences would be. One water sample taken for all tests.

My kit :
FC2.5
CC 0
pH7.5
CH 120
Alk 100
CYA 40
Salt 3000

Store1:
FC 1.6
CC .2
pH 7.6
CH 120
Alk 80
CYA 40
Salt 3100

Store2:
TC 3
pH 7.4
CH 220
Alk 100
CYA 30
Salt 5100
 
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amieelynne

Active member
Jun 5, 2007
33
Massachusetts
#9
well now I know not to trust the pool store. did a complete testing today and there is NO cya in my water therefore there is NO chlorine...yet again!! after the chemical dump last night, I thought I would be good but no...today while I was at work they shut the filter off--they just can't grap the concept that the filter has to be on for the chlorinator to work :roll: so I plugged that back in today at 3pm...tested

chl 0
ph 7.2
ta 80
cya 0

dumped in another gal of shock (at this rate I'll be out of the free stuff in no time) and 3lbs of stablizer. here's hoping this will do the trick. think I need to add some plain old chlorox tonight too? the shock says 1/2 gal for 10,000 gal of water...brought it up to a nice level last night but it must have all burnt off today with no cya in the water
 
G
#10
Hmmmmm. I work in a pool store and spend a good part of my day testing water. From the sound of this thread I can't trust my own results! :poke:
 

Buggsw

LifeTime Supporter
Apr 22, 2007
925
Arizona
#11
There, there Waterbear. I tried to defend some pool stores, saying that not all of them are bad. We know, you are one of the best! Unfortunately, the good ones seem to be few and far between.

Leslie's gets a bad rap, but I've found them to be closer to my own tests than anyone, plus they automatically write it all down with dosing instructions on a form and you know they have never, ever tried to sell me really odd stuff based on the results. It's usually you need to add x amount of acid, you need to put x much chlorbrite. Hmmmm, that could be because I do maintain my pool very well, though. I already know what I need to add and only have them test on occassion when I'm wondering about things I don't have a kit for. The use drops and if I recall they are always Taylor. Anyway, I like Leslie's.

I cannot believe how many pool stores out here just start dropping the drops and swirling the tubes or dipping the strips and never write it down for the customer. That always makes me suspect of them trying to hide the truth and push the unneccessary products.

One dumpy local pool store here can't get anything right, it seems. The other day I tested my water with 2 different drop kits plus a FAS/DPD kit and a brand of dip strips that I like pretty well. This is the pool store I buy my liquid chlorine, it is one good thing about this store - it's always fresh chlorine, made in Tucson and brought in daily.

Well, anyway where they test is in a dark corner in a dimly lit store. The testing area and tubes and such is an abomination. They test with drops and with strips. OMG, he wasn't even writing it down anywhere. He's telling me I have x chlorine, uh huh, a little different. He says my pH is x, a little bit off, as well. So, he then tells me I have either 0 TA or 40 TA. His AquaCheck strips registered 0 and his drops registered 40. Wah???!!! Almost impossible here in Arizona. In my 3 tests, at home, I had TA of 90. Now this was a fresh sample - the store is 5 minutes from my house. How do you explain that?? Other than, I am sure the AquaCheck strips are totally wrong - I really don't like that brand.

I've never had my water tested anywhere that used a machine - though, there are a couple places that have them, nearby. Maybe this weekend, I'll give it a try.
 

DaveNJ

LifeTime Supporter
May 22, 2007
520
Toms River, NJ
#12
I noticed the same thing as Buggsw stated, plus get the test done and on to the next. Store1 used an automatic tester. They used the same small vials for the person in front of me and didn't rinse them out very well. Don't know how often they calibrate. Store2 used drops and strips. Station was in the back corner and a complete mess. Drop bottles were all open, didn't rinse vials just dumped them.
I actually was trying to get a borate test done for reference. Thinking about going the borate route for pH buffer.
Store1 was my PB. The person that tested the sample stated "We've been selling SWCG for 2 years and I've never seen a problem with SWCG raising pH. If it was something that needed to tested they would have told me."
 

momof2grlz

LifeTime Supporter
#13
waterbear said:
Hmmmmm. I work in a pool store and spend a good part of my day testing water. From the sound of this thread I can't trust my own results! :poke:
Waterbear, you're the exception to the rule!!!! :super:

And. . . most of the pool store employees I've encountered are about 20 years old and didn't know a pool needed anything but a float and a cold beer until last week when they started working at the pool store.
 

vejadu

Well-known member
#14
I use a local pool store. I watch them test and they do a pretty good job. They rinse the vials with tap water not pool water which bugs me, but they are usually right in line with my own results...except lately. I think the problem might be the inexperienced teens they hire in the summer. I had to tell them how to read the salt test one day!
 

vejadu

Well-known member
#15
I use a local pool store. I watch them test and they do a pretty good job. They rinse the vials with tap water not pool water which bugs me, but they are usually right in line with my own results...except lately. I think the problem might be the inexperienced teens they hire in the summer. I had to tell them how to read the salt test one day!
 

From_Arizona

LifeTime Supporter
May 8, 2007
212
Glendale, AZ
#16
I have to say that my local Leslies, one tester in particular, did a good job on my last pool. He helped determine that my SWG never operated at optinum. We sepnt almost 2 years adding chemicals to keep the water somewhat balnced.....finally go tthe SWG replaced and whalla ==> found out how easy a SWG makes the pool!
 

MarkC

Well-known member
May 14, 2007
57
#17
My local pool store in Doylestown PA tests the water using a computer system and little premade cells/vials that have the reagents in them. With the exception of one time when the new kid did not know how to accurately transfer 1 mL via a pippetor the results pretty much match my own testing. I don't see them pushing a lot of unneccesary stuff on people while I am there. I just wish they would stock plain old calcium hypochlorite in the buckets and not the tripple action junk with stuff I don't want.
 
G
#18
MarkC said:
My local pool store in Doylestown PA tests the water using a computer system and little premade cells/vials that have the reagents in them. With the exception of one time when the new kid did not know how to accurately transfer 1 mL via a pippetor the results pretty much match my own testing. I don't see them pushing a lot of unneccesary stuff on people while I am there. I just wish they would stock plain old calcium hypochlorite in the buckets and not the tripple action junk with stuff I don't want.
Sounds like they use a LaMotte Waterlink Express and the LaMotte Unit Dose Vials. It's a good system. We use it where I work also (but I use a TF Testkit at home!) and the results are vey accurate if they allow proper development time for reading the vials. The automatic pipette transers 3 ml of water to each vial, btw, and does take a bit of getting used to to do it right.
 
Jun 2, 2007
6
SW Missouri
#19
WaterBear,

What is the proper development time on those tests? The system described sounds like what one of my pool stores uses. Little square vials with foil coverings that the tester punches thru with the ?pipette? [learn a new word every day]. The vials are probably somewhere bt an inch or two in height and the color of foil varies, assuming with the different test. I tink what my store does is just fill all the vials at once and then run them thru the meter one by one. I assume that the vials first filled are the first anlayzed but it doesn't appear that there is any set wait time.
Is that what you'd expect?


I just recently purchased the LaMotte ColorQ and am enjoying the geek factor but the directions never mentioned any wait times except for the CYA test. Based on your experience with other LaMotte products what special procedures would you recommend (i.e. wait time after adding drops before analyzing or wait time bt adding reagent 1 and reagent 2, etc.)

Thanks,
Mike