Pool Chemisty

Apr 12, 2017
16
new caney tx
#1
New to all this just did my first test with a TF-100 my numbers are way off. Pool is 16 x37 IG I think fiberglass built in 09.

FC 3ppm
CC .5
TC 3.5
CH 450
TA I added 30 drops no reaction I'm assuming that means 0
CYA 110 only measures to 100 to I estimated
PH 8.2 Didn't see any other way to test except the small test kit. Is this right
Since my numbers were so way off I could not figure out the calculator.

Tried adding the info to my signature but could not figure out where to put it. Thanks for any help I can get.
 

triptyx

TFP Guide
Apr 12, 2016
1,485
Tucson, AZ
#2
Welcome to TFP! It's awesome you already have a good testing kit. :)

You can edit your signature here: Trouble Free Pool

CYA - you need to do a dilution test. Mix half pool water and half tap water together and use that as your sample. Divide the result by 2 and you can get a better read of your CYA - the scale is logarithmic so it's not very effective to estimate if it's near 100.

The small test kit is the proper way to test pH - that's correct.

First things first, add muriatic acid to get your pH down to around 7.6 or so. Once that's done, you need to get your chlorine levels up to at least 10 at a minimum (as in, don't let the pool drop below that number) - target 14 to 16. That's based on a 125 CYA - if yours turns out to be higher, you'll need to push it higher. Unfortunately, a water drain/fill is going to be in your future - let's see what your final CYA number lands at.

With CYA numbers like that, I'm guessing you (or your pool service) has been using solid chlorine - such as tablets or granular "shock". That is what causes that out of control CYA number. Going forward, you'll want to stick only to liquid chlorine or unscented, plain bleach (make sure it's not splashless or "EZPour").

Can you please tell us what your water looks like? Is it nice and clear or is it getting cloudy? What color is it?
 
OP
OP
H
Apr 12, 2017
16
new caney tx
#3
My pool water is clear Actually had a pool guy come out about a week ago to fix a leak and he said my pool looked real clean.
Yes I'm guilty have been using the pucks first time having a pool since June last year had a pool guy come out and teach me how to maintain. Guess that was a mistake. LOL
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#4
Welcome to TFP! :wave: Good notes above. As for the TA, hummmm.... how about try a test on your tap water? I'm curious to see what you get there. Usually there is "some" alkalinity in the water. It would be good to get that resolved. Great to have you with us at TFP.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#6
Hilda, perhaps we confused you. Sorry if we did. The diluted water test is just for the CYA and needs to be done with 1/2 pool water and half tap water. Like this:
CYA Dilution Testing:
Add pool water to bottom of sticker.
Add tap water to top of sticker.
Shake.
Pour out half so mixture is to bottom of sticker.
Add reagent to top of sticker.
Shake.
Test outside with back to sun and tube at waist level.
Pour back and forth a few times to see if you get the same result.
Double the result.
For the TA re-test, since you showed a "zero" in the pool, I'd like for you to try a tap water test just for the TA - no diluting on that one.
 
OP
OP
H
Apr 12, 2017
16
new caney tx
#7
I re-did some of my tests
CYA 120 dilution method
TA 120
PH 8.2
Went to home depot bought my muriatic acid now to figure out how much to add.
Other question How can I figure out if my pool is fiberglass? Equipment has an 08 date if that helps.
Thank you for all the help.

- - - Updated - - -

I added my info on the signature. Why is it not showing up? I made sure to save.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#8
Well, for the type of pool, if it's fiberglass (like mine is), it will simply be a hard shell with no plaster or vinyl coating. If you're still not sure, maybe take a picture and upload for us to see. That TA number looks much more like what we would expect to see. As for the pH, you already know it's high, and the muriatic acid will do the trick to lower it. The way to know "how much" acid to add means using the POOLMATH calculator that we list at the top of the TFP web page. To use it, you need to know how many gallons your pool is. Do you know the pool volume? If not, you can give us some measurements and we can try to help.

Now before doing too much to the water, we know your CYA is too high since you got a reading of 120 (that assumes when you did the diluted sample you actually got 60 then x 2 = 120). So anytime CYA is over 100, we recommend exchanging some water. Unfortunately that's the only way to lower CYA. Good thing is that once you lower the CYA, it will not go back up again as long as you don't use pool store tablets/pucks, bags of chlorine powder, or add stabilizer on purpose. With a CYA of 120, you should try to exchange about 1/2 of the water which will get you to a new CYA of 60 - perfect for the upcoming summer TX sun.

So I would recommend first exchanging the water to adjust the CYA to about 60, then you can re-test pH and adjust it as necessary. If you have any problems with the Poolmath calculator page or calculating your pool size, let us know and we'll try to help.
 
OP
OP
H
Apr 12, 2017
16
new caney tx
#12
Did a partial drain this weekend.
My new numbers are:
FC 15
CC 2
TC 17
CH 275
CYA 80
PH 8.2
TA 130

I realize my FC is to high my husband snuck in some bleach. He thinks if it don't kill the ants it ain't high enough also if you can't smell it. This has been an ongoing argument.
I think all my other numbers are ok. Do I need to worry about bringing the chlorine down?
Thanks for all the help.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#13
Okay Hilda, at least the CYA is a bit lower. Your chlorine isn't all that bad because your CYA is still on the high end. You mentioned earlier that your water was clear, but I see your CC reading is a bit elevated. It could just be a temporary thing, but it needs to be watched. Here's what I would suggest at the moment:
- Use muriatic acid to lower the pH to under 7.8 - perhaps about 7.6 or so. The color blocks can be tricky, but definitely under 7.8.
- Leave the FC elevated like that for tonight and consider doing an overnight (OCLT) test. Pool School - Perform the Overnight FC Loss Test (OCLT) It would be good to ensure there are no excessive organics trying to live in the water.

That's really about it for now. Lower pH and watch the FC. Hope that helps.
 
OP
OP
H
Apr 12, 2017
16
new caney tx
#14
A few more questions.
My numbers on Thursday about 4 pm:
FC 15 ppm
CC .5
PH 7.5 added muriatic Acid to bring it down

Today:
FC 12.5
CC .5
PH 7.5 added more muraitic acid
CYA 80

Was wondering my swimming pool fountains are always on when the pump is on. Can't turn the dial to shut them off husband can't seem to turn it also. Could this be affecting my ph?
With a CYA of 80 if I'm reading the chart correctly my FC should be 9-11 is it ok if it is higher? can we still swim in it?

Thank you for all the help

20170421_172332.jpg
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#15
Hi Hilda! :wave: Pool is looking great. Yes, fountains/bubblers/spillways cause aeration which is a natural way to increase pH. Usually there is a valve "after" the filter which allows you to adjust how much flow goes to the return jets versus bubblers, spillways, & fountains. Hopefully there is one or you can find it. Since your CYA is at 80, going slightly over the recommended range to 12 will not hurt you a bit. It is safe to swim...... even up to 31! :swim: Enjoy that nice pool and have a nice weekend.