Newest numbers...need some reassurance and insight....


Well-known member
Sep 19, 2007
I don't know why I keep taking my water to the pool store, but we had to go to town and it was on the way so I took it.
Their numbers are:
FC 3.7
TC 3.9
CH 240
TA 90
pH 7.7 CYA 68

I came home and used my TF test it and got different numbers. I am more trusting of my that right...
My numbers:
FC 7
CC 0
TC 7
CH 360
TA 110
pH 7.8
CYA ~57 (closer to 55 than 60)

I wondered why they came out so low on FC and showed CC. That bothered me so I tested it and my gut was was higher than their reading and no CC. I just turned my SWCG down from 35% that had me at FC of 7 to 30% to get a tad closer to 6. But if I can't get it right is it better to be on the high end of the ideal in the CYA/FC chart or the lower end? Would FC of 7 be alright? Should I just not mess with it?

What would cause the big discrepency in the CH and the FC? Are their tests just that inaccurate? I did the tests exactly, took my time, did it drop for drop so I now I did the tests accuratley.

Also, I am trying to get my CYA up. I added 4 pounds of it on Monday and according to the pool store went from 45 Monday to 68 today but my test came in between 55 and 60. Should I wait a few more days and test again and add some more stabilizer?


Mod Squad
LifeTime Supporter
Platinum Supporter
TFP Expert
In The Industry
Apr 1, 2007
Sebring, Florida
Hey, Sarah,

From prior postings over the years, the pool store results look like test strips placed in a digital readout. Results from those tests seem to be most unreliable with CYA and CH.

Whether it's the TF-100 or the good Taylor kit, I believe you'll always get more accurate results doing your own testing.

FC of seven is fine but I believe you can turn down the SWG a little more.....shooting to maintain around 5ppm.

Most SWG's seem to like 60-80ppm but I wouldn't add more just yet. It's not uncommon for CYA to take a full week to register correctly on the test.

I think you'd do better to test again on Monday or so and, if you're still lower than 60, target enough to get you up to 70ppm.......the idea being not to overshoot since it's such a PITA to reduce it once it gets up there.


LifeTime Supporter
May 4, 2007
I take my pool water to two major chains here in So FL and it is hit and miss. I used go to them at the beggining to double check my own tests because I was unfimiliar and not sure I was doing them correctly. It soon realized that once you do the test a couple of times it really isn't Rocket Science. I had a CH problem where it went to 430 per my test and I took my sample a week later to the pool store and they told me 400 which is close. Thinking my CH issue was growing (due to curing plaster) I took it again a week later and they told me it was fine at 320. I tested myself and got 430, same thing 3 weeks prior. So as you can see, my test was the same both times at 430, the pool store tested 400 and 320. So, even if I am doing it wrong, I am close to the 400 that the pool store said which verifies I am doing it right.
I think for the most part the pool store is in a hurry and just squeeze the he** out of those bottles and don't count right or the drops are smaller. That is why in the instructions it tells you to hold the bottle straight .


LifeTime Supporter
TFP Expert
Mar 29, 2007
Coastalish 'down easter'
Another thing that can throw off the testing is TIME, if you take the water from the pool at 9 am and leave it sitting in the car exposed to sun, etc while running errands and don't get it tested at the pool store ( :oops: - sorry to use bad words in a post :lol: ) the results at the store could/ (would?) be different, even if you tested it yourself with your GOOD kit at the same time. (Evan or Dave or Richard or anyone else, care to correct or support me?)


LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
Silver Spring, MD
Chlorine seems to "vanish" fairly quickly on the way to the pool store. Some experiments done over at PoolForum some time ago showed chlroine levels starting to fall after only 10 or 15 minutes of sitting on the counter in air conditioning. The remaining tests are far less sensitive to wait time.


LifeTime Supporter
TFP Expert
May 31, 2007
South Carolina
Being somewhat of a newbie myself (two seasons w/bbb), BUT WITH A GREAT TEST KIT, I can tell you that you should trust your own numbers and just forget about the pool store. When your pool is clear and sparkling, your neighbors (pool stored) could have a green swamp. I saw a lot of this last year but especially this summer. Have faith and trust your own testing! Your pool and family will thank you! :wink:

It does sometimes seem like a leap of faith, but if you trust the folks here, you will not go wrong and it will all be worth it! :)