Help maintaining TC level

wingedout

Member
Sep 24, 2018
17
Midland, TX
Hello all,

So we have been using bleach 6% for about 2 months now. (we did use the 3" pucks for the first few months recommended by pool builder) And are having a hard time maintaining the TC at 4.5 our CYA is a little high 50.

I guess here are our pool details:

21,000gals
Plaster
new build finished 03/2018
Pentair Clean and clear 520 cartridge
Pentair 3.0HP/3.95 SFHP with Booster-Rite
Spa
and auto filled with RO water (reverse-osmosis)

We tested every day this weekend and had to add 4ppm of chlorine to our pool everyday. So I did a full test yesterday (9/23) to try to figure out where the Chlorine was going.

Here are the results
FC-1. CC-.5 CYA-50 ph-7.5 CH-500ppm TA-80

So we decided to SLAM it and added 880oz of bleach last night around 9PM. Tested it this morning at 8:30am and we are at FC-.5 and CC-1 with the k-100 test I got TC- .5 to 1 range and ph 7.5. I added 175oz of bleach this morning.

We need some direction on what to do now. Should I have shocked it again to 20ppm and added the 880oz again this morning? Our water is clear never been green but we assume since TC always went so low we must have some kind of invisible bacteria in there.

Please any help is greatly appreciated.

Thanks,
Dora
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,411
Franklin, NC
Welcome to the TFP pool! :splash:

First a couple of comments and questions-

What test kit are you using?

We do not care/track TC, only FC & CC

When looking at teh [FC/CYA][/FC/CYA], the first column is not how much you shuld add each day (like you say adding 4ppm per day), but what is the minimum you should have and maintain at all times. So, For 50 CYA your minimum FC should be 4, and you should target 6-7 to keep it above 4

A one time addition of chlorine is not a SLAM Process. A SLAM Process is a process that takes place over days and is conducted by maintaining the 20 as much as you can. Read thru the directions.

Tonight you need to conduct an Overnight Chlorine Loss Test. After dark, add 3 bottles of 6% and wait 30 minutes with teh pump running. Once the bleach is mixed well test FC. That is your starting number. Before the sun rises tomorrow test FC again and see how much FC you lost.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,426
Laughlin, NV
Welcome to the forum! :handshake:

Can you tell us what test kit your are using for your chemistry testing?

Based on your numbers as shown, you should SLAM Process. Read the article. You maintain the shock level FC (20 ppm) until you pass the three criteria.

Please add a signature. Read Pool School - Read This BEFORE You Post
Information in your signature will show up each time you post and it makes advice more accurate as we know what equipment we are dealing with.


I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
We use the trouble free 100 kit. Thanks so much for the information. We have been using your site for several months now also. I just needed more help. Thank you for clarifying the SLAM process. I did read it last night but couldn't find same page this morning. Will print it out this time. And we (husband and I) have read most of you alls info. My memory is just awful.

Hope my signature works. Created it a few mins ago.

So should I add the 705oz to get back to 20 now. Or should I just wait to do the overnight chlorine lost test tonight?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,426
Laughlin, NV
I would suggest doing both. Raise your FC to shock level and maintain it today. This evening, take a final test of the FC after the sun goes down and test it again in the AM. Be sure to run the pump at a low rpm constantly during the SLAM and OCLT.

- - - Updated - - -

I notice you filled your pool with RO water, good idea in Midland. What are you using for makeup water?
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
Good evening all so wanted to thank you all again for your advice and thought I would give an update where we are with our slamming process:

9/24 Monday at 10:30AM I added 705 of bleach after consulting with you all (then had to leave the house for work and kiddos)
9/24 3:11PM FC-7 CC-.5 added 572oz of bleach
4:35PM FC-19 CC-.5 added 44oz of bleach
5:15PM FC-17 CC-.5 added 132oz of bleach
6:00PM FC-18 CC-1 added 88oz of bleach
6:45PM FC-19 CC-.5 added 44oz of bleach
7:37PM FC-18.5 CC-.5 added 66oz of bleach
8:24PM FC-18 CC-1 added 88oz of bleach
9:03PM FC-19 CC-.5 OCTL reading
9/25 7:15AM FC-7 CC-.5 added 572oz of bleach
8:24AM FC-22 CC-1 left alone
9:30AM FC-21 CC-.5 left alone
10:49AM FC-20 CC-0 left alone (had to leave for work and kiddos)
3:30PM FC-12.5 CC-.5 added 330oz of bleach
4:50PM FC-17 CC-.5 added 132oz of bleach (had to leave again)
9:30PM FC-14.5 CC-.5 added 242oz of bleach
10:00PM FC-20.5 CC-.5 OCTL reading

So I will check tomorrow morning around 7AM. I do know that my R-0003 has turned yellow (which I read that it is now bad). I am waiting on more to arrive. I ordered refills yesterday. I hope I have enough R-0871 to keep testing tomorrow. It feels low. Guess I should of paid for expedited shipping.My husband and I are planning on changing out our cartridges. (We keep a spare and rotate them out.) We are thinking this might help speed up the slamming process? People sure do stare when you buy 25 bottles of bleach at wal-mart. Tired to attach a photo but don't know how. Oh and water has been clear the whole time.

If you have any more pointers or areas of concern please let me know.

thanks,
Dora
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,426
Laughlin, NV
Clean your filter when the pressure rises by 25% above your clean pressure.

Looks good. Clear water is good. Should go pretty quick as closely as you are monitoring it.

Good job.
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
Do we need to keep an eye on our ph? And the first two days I would only add bleach to the main pool. Today I started adding some to the spa that spills over into the pool. (waterfall effect) hoping that would get us done with the slam. It did rain today so I think that messed with it. Didn't get to change cartridge since it was raining while we were home and then got dark on us. Going to do it tomorrow.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,426
Laughlin, NV
pH test is not valid when your FC level is above 10 ppm.

No need to add directly to spa. Your system flows at least part of your water through the spa if it has a spillover. The water is one system.

Rain does not do really anything, unless it is of Ark proportions. You have a huge cartridge filter. I can't imagine you need to clean it more than once a year, if that.
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
Ok good to know on the ph. I am sure we missed it somewhere.

Here is how today went. ( a little sad our FC fell 1.5ppm in 30 mins for the OCLT last night it actually read 20.5 for this reading so it maintained. Maybe because I didn't test as much as I was able to yesterday)

Day 3
9/26 7:08AM FC-12 CC-1 added 352oz
8:50AM FC-20 CC-1 added 0
2:46PM FC-15 CC-.5 added 220oz
7:09PM FC-16 CC-1 added 176oz
7:55PM FC-18 CC-.5 added 88oz
8:35 FC-18.5 CC-1 OCLT reading

here is more slamming tomorrow. Goodnight all
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
Hello again,

Tested this mornings reading for OCLT and we dropped 5.5ppm. We are headed out of town Saturday and I am afraid I won't be done with our SLAM.
I guess it has gotten a little better:
1st night drop 12ppm
2nd night drop 8.5ppm
3rd night drop 5.5ppm

We are returning Sunday but I won't be able to do the OCLT test saturday night. So I feel like I have one more day to get this right.

Any pointers to what to do since we will be gone that night? How many days does it usually take? Hoping to get the refill kit on testing stuff today. Almost out of R-0871.
Should I recheck the CYA maybe my level moved and 20ppm for FC is no longer the right SLAMMing goal. Appreciate any help.

Thanks
Dora
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,426
Laughlin, NV
CYA would only drop due to water being removed from the pool. Have you had overflow from rain?

Raise your FC to SLAM level before you leave and deal with it when you return. You might back track some but not much you can do unless you can have someone add a jug or two of bleach while you are gone.
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
It rained but nothing to overflow or even close. Can the CYA go up on its own? I was just worried that maybe my FC goal should be higher than 20. I will see if my neighbor can throw some bleach in there for us.
 

wingedout

Member
Sep 24, 2018
17
Midland, TX
So today is day 7 and still SLAMMING. dropped 3.5ppm in OCLT. We are leaving Wednesday and don't come back until Sunday. Was hoping to be done with the SLAM by then. But it is not looking good. What should I do if we aren't done by Wednesday morning?

one positive note we found 8.25% bleach at our local HEB and same price as Wal-mart's 6% stuff.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,426
Laughlin, NV
If no one can add bleach while your are gone, you raise it to SLAM level before you leave and then you deal with it when you return.

What do you do to normally chlorinate when gone for 5 days?