Test results ....next

May 19, 2008
4
Durham, NC
#1
I have a 20,000 gallon painted gunite pool. Am new here but have read about bleach use and sounds amazing. So I think I am ready to give it a try. Can anyone tell me how to get started? Test results are as follows
CYA= 137
Total Chlorine = 6
Free Chlorine = 5.7
PH = 7.9
Total Alkalinity = 121
Adjusted Alkalinity = 80
Total hardness = 365

thanks for any advice you can offer also if I use the bleach do I need to dilute and what is the follow up using bleach?
 

whoozer

LifeTime Supporter
Apr 2, 2008
633
Acton Maine
#2
First off welcome to TFP! Second it always helps the gurus if you post all of your equipment at the bottom of your sig. Third. Your CYA is really high. Before you do anything I'm thinking you'll need to empty some water and refill to get the cya down.
 

Butterfly

TFP Expert
LifeTime Supporter
May 31, 2007
10,045
South Carolina
#3
Welcome to the forum!

How was the testing done? Pool store? or kit, if kit, which one?

The big thing that needs correction is your CYA issue. If the CYA is correct, or even near correct, you will need to replace some water to get that level down to something reasonable. (30 to 50 for chlorine and 60 to 80 for SWG)

Lower your pH back to around 7.2 to 7.6 and maintain that level.

Please list all your pool and equipment info in your signature. This is needed to help members give good advice!

There are lots of folks here waiting to help you take control of your pool. :lol:
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,271
Sebring, Florida
#4
To reinforce what whoozer said, your CYA is almost unmanageably high and needs to come down. That said, that test result is probably from a computer readout of a strip and they're awful at testing CYA.

If you don't have your own kit to test CYA, I suggest you go to a different store to confirm that CYA test. Post the results and lots of folks will help you get started on bleach.

PS - think of the bleach as just another delivery method for chlorine. You are currently delivering chlorine to your pool with something else (looks like cal hypo) but they're both chlorine delivery vehichles. The BIG advantage of bleach is it delivers NOTHING else to your pool that causes a probllem. Most of the other methods DO bring unwanted side effects
 

MikeInTN

TFP Expert
LifeTime Supporter
May 28, 2007
1,335
Middle Tennessee
#5
gammonlvr_99 said:
I have a 20,000 gallon painted gunite pool. Am new here but have read about bleach use and sounds amazing. So I think I am ready to give it a try. Can anyone tell me how to get started? Test results are as follows
CYA= 137
Total Chlorine = 6
Free Chlorine = 5.7
PH = 7.9
Total Alkalinity = 121
Adjusted Alkalinity = 80
Total hardness = 365

thanks for any advice you can offer also if I use the bleach do I need to dilute and what is the follow up using bleach?
BBB is easy, once you get your water chemistry straightened out, which is the first thing you need to work on. First, read this sticky which is the ABC's of pool chemistry. This gives you the recommended ranges you need, and will help you understand why I'm suggesting what I am below.

(1) Your CYA is way too high. Ideally you want it around 30-40 if not using a SWCG. With your CYA so high, you need a bunch of chlorine just to maintain sanitizing levels. Unfortunately, the only way to lower CYA is to remove water. I think the general consensus is you can lower your water 18" below your skimmer, and then refill, test, and then repeat. With your CYA that high, you're going to have to do this step several times.. sorry :cry:

(2) Your pH is borderline high, probably because your TA is borderline high as well. Use Jason's pool calculator here to determine how much muriatic acid to add to lower your pH to around 7.4 - 7.6 . To lower your TA, add enough acid to bring your pH down to around 7.2, then aerate your water using a return jet or a spa, waterfall, whatever you have. check your pH and TA the next morning, and repeat until your TA is around 100 or so. Check your pH, and either add borax to raise it if needed, or acid to lower it if needed. When adding acid, add it slowly in front of a return, or walk around your pool and drizzle it in the water - do not just dump it in (this applies for bleach, too).

(3) You're underchlorinating your pool right now (see #1 as to why). Using Jason's pool calculator, for CYA=137, your FC should be between 11 and 17 to maintain the proper sanitization of the pool. I'd get my CYA down as quick as I could. For example, for your size pool, to reach FC=14, you would need to add 3.5 jugs of 6% bleach to get to 14. If your CYA was 40, then your FC needed for sanitation would be between 3 and 7, and you would be there already, and it would take a cup or two every evening to maintain this level.

So, to recap, get your CYA down by doing partial drains and refilling, get your pH and TA down by adding acid and aerating, and then you should be good to go!

To answer your question about bleach, there's no need to dilute it, just know what strength you're using (6% or 12%), use Jason's pool calc to figure out how much you need to add, and add it slowly in front of a return. Plain old generic bleach is best; no scented or other ingredients other than sodium hypochlorite.
 
May 19, 2008
4
Durham, NC
#7
Thanks for all the input. The test was preformed at a pool supply store on a strip read by a machine. I have added my info in my signature line. And I live in a drought area so dumping and adding is not an option this year. City would shut off my water if I tried that. So with that said and my cya so high would it be ok to just keep the free chlorine level high to maintain it. And also where may I find a good home test kit? Again thanks !