Can my test results really be right?

jfitz0807

Member
Oct 21, 2009
7
pH - 7.3
FC - 10
CC - 0
TA - 80 (a few days ago)
CYA - ?

New pool in the Boston area. Water went in on Aug 10. Startup company came on the 11th. We started the pump and they put some chemicals in the pool. I think it was mostly baking soda to conteract the acid wash of the pebble sheen. I checked the pH every day and kept it around 7.3. The weather was bright sunshine and high 80's most of the time. Wife and kids were away, so no-one went in the pool. Startup Company came back on Aug 20. They shocked the pool (Di-chlor?) and left 5 chlorine sticks in the skimmers (2 in one, 3 in the other). I checked the chlorine level and it was off the chart. On the CYA test, the black dot was visible even when the tube was completely filled. The solution never got cloudy.

Since then, it's been in the 60's and raining. The kids and I have still been using the pool in the rain for about an hour each night. We also had a few other kids in on the 22nd. The heater has been on and off. The pool temparature has been fluctuating between 75 and 82.

I noticed Tuesday, 8/24, that the chlorine sticks were gone. Using my Taylor test kit (Startup company provided it), I checked the chlorine level. It was over 10. I did the test twice, once full-scale (9mm of pool sample) which was off the chart and again at half-scale (4.5 mm pool sample with 4.5mm of tap water) which was still off the chart. Both times, there was no noticable difference when I added the third reagent to check for combined chlorine. I was getting really wet from the rain, so I didn't do the 1/5th scale test. I figured that since it was so cold with no sun that there was still residual chlorine from the shock and the sticks. This moorning, I tried the chlorine and CYA tests again. The CYA test still showed no cloudiness in the sample. The 1/5th scale chlorine test looked like about a 2, so I figure my free chlorine is 10. Still no change when I added the third reagent, so it looks like my combined chlorine is 0.

Can my test results be right? Is it possible that I haven't used up much chlorine due to the weather?

Today it's sunny and expected to go to low 80s. My son will have several friends over to swim most of the afternoon and we're having guests tonight. I bought 3 gallons of bleach yesterday to have on hand. I was planning to check the chlorine level again before dinner. If necessary, I will add bleach so we can go swimming after dinner. Is there anything else I should do?

The pH has been pretty steady even with the rain. I have kept it at about 7.3 by adding a little over a pint of muriatic acid every two days, so I think my Total Alkalinity is O.K. WHen I checked it on the 20th, it was about 80. I forgot to check it this morning.

If my CYA sample is clear, does that mean I have to much CYA or too little? With all the rain, the pool almost overflowed, so I drained about 3 inches yesterday.

My signature says we have a SWG, but I haven't turned it on yet. Pool company said to wait 30 days after the water goes in.

Thanks for the help.
 

jfitz0807

Member
Oct 21, 2009
7
Forgot to add in the previous post that I don't know the CH number. When I tested it on 8/20, it was about 300, I think. I didn't test it this morning.

The water looks pretty clear. While using the leaf rake this morning, the water gets a little cloudy as the rake moves through it, but then it clears up quickly. I think my in-floor cleaning system is not working as well as I would have hoped. It seems like that's the source of the cloudiness rather than a chemical issue, but I could be wrong.
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
I would go ahead and add some CYA. Add enough to reach 30ppm, that way if you have less than 20-30 (and its just not enough to register on the vial) you won't overshoot and end up too high. Use the Pool Calculator to determine the correct amount.

I also recommend you supplement your kit with an FAS-DPD test, that way you don't have to use dilution methods to accurately measure the chlorine.

Otherwise I think you are doing fine.... (what are your plans for the N2?) :)
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
Which Taylor kit did they provide? Sounds like it wasn't a DPD-FAS capable or you would know. DPD-FAS chlorine tests go to 50 ppm.

You can dilute your pool water sample with distilled water. Try a 50/50 split and multiply the results by 2. Next season, buy a TF-100 kit for testing.

You have a very low CYA level.

Since the sun will be out today, I expect the FC level will drop significantly by the time you get home.

Check the calcium level too.

Buy some CYA/Stabilzer/Conditioner (all the same stuff) to start bringing the level up. Add 1/2 recommended , wait 3 days. Test and add as needed to get to 70 ppm.

You can safely salt the pool. Test the level currently and add 2/3 of the expected needed amount. Brush each bag thoroughly. There may be a rock in the salt bag. Happens often. Please remove it. Test the level the next day and add as needed. Wait another day and test. If the level is right, turn on the cell.

Use bleach to manually dose the pool until the cell can take over.

Test your fill water too.

FPM is quick this morning.

Scott
 

jfitz0807

Member
Oct 21, 2009
7
Thanks so much for the quick replies! I'll pick up some CYA at lunchtime. Maybe I'll get a FAS-DPD test as well.

They did put salt in my pool when they shocked it, but for now, it's more of a softener. I'll still wait the 30 days before firing up the SWG. If anything does go wrong, I don't want to run into warranty issues.

My original plan was to just use the bleach for chlorination for the next two weeks. Since Dichlor and tri-chlor raise the CYA level (I read Pool School), am I better off just getting a bunch of pucks and keeping them in the skimmers for the next two weeks?

I was told that with the N2, I could keep the chlorine level lower. My daughter is very sensitive to chlorine, so we are trying to keep it as low as possible. We haven't put that cartridge in yet either. I was going to do it at the same time I fire up the SWG.

Thanks again.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,796
San Dimas, CA (LA County)
What Pool Mom said.

You probably won't find the right test kit in the local stores. tftestkits.net can set you up. I recommend a TF100 and a speedstir. As long as you store it in the house over the winter, it will still be fine next season.

As an aside, if you become a site supporter, you can get a discount on the kit.
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
Throw away the N2 cartridge. It's injecting metals. N2 lies about lower FC being needed. Test the salt level. Salt doesn't soften water. Removal of calcium does. It's OK to turn on the cell with PS after a couple weeks of application.

Scott
 

Other Threads of Interest