New to pool chemistry management

[phoenixwtc]

I've had a Hayward salt system for the past three plus years. Until now, I've always had a pool service handling the water condition each week. Recently, our pool tech has had difficulty figuring out why the pool is running low on chlorine. She suggested the Hayward chlorinator might have gone bad. Since this is no small cost item, I decided it was time to learn the operation of this pool. Not that I have any interest in dropping her, but to make sure I understand how it all works. I went out and purchased the Taylor K-2005 test kit and spent a lot of time reading up on pool chemistry. It took me a week or so, but I came to the same conclusion that the chlorinator wasn't working completely and went out and bought a new Hayward TCellS340 to replace the OEM Hayward T-cell-15. I replaced the cell myself since it didn't appear to difficult (two couplers and a plug). This particular Hayward cell is not listed in the config menu for cells, but according to the manual for the new cell, it shows it to be the correct replacement for the tcell15. Everything seemed to be working fine over the past week, but then I noticed the chlorine levels dropping off again. Today, our tech tested and found zero chlorine. The diagnostic menu shows -25.3V, -7.69A, and 3400PPM. The tech added chlorine to the pool, so of course the chlorine readings are high right now. I'm curious as to why getting the "Check System" showing up on the remote display. BTW, the circuit board for the chlorinator died last year and was replaced under warranty by the poll constructor. Thoughts on what I did and/or why the check system light is showing up? Thanks

 

[kellyfair]

What is your CYA?

I don’t know the ins and outs of what pool services do, especially with a SWCG installed, but do you know what is being added to your pool on a regular basis? If so, please share that here, and if she is testing your pool, can you share those test values as well?

I would get a better test kit (see below) and test for yourself.
Test Kits Compared

 

[proavia]

Welcome to TFP!

While the Taylor K-2005 is an okay kit, you need to add the K-1515 FAS-DPD test kit to make it equivalent to a K-2006 test kit.
Is your test kit a K-2005 or K-2005C?

Since you have a SWG, youalso need a K-1766 Salt test kit to accurately measure the salt content. While the SWG will show a salt level, it usually isn't the actual salt level of the pool water.

Post a full set of current test results - or at least the ones the K-2005 will provide for now.
FC
CC
pH
TA
CH
CYA
Salt
Water temperature

Have a read thru
Pool Care Basics
Become familiar with
FC/CYA Levels
PoolMath
Overnight Chlorine Loss Test
SLAM Process

Inspiration
How Clear is TFP Clear?

You need to know an accurate CYA level so you can add liquid chlorine to maintain a sanitary pool while you work on your chlorinator issue. After you know the CYA level, use the FC/CYA Levels to determine the needed FC target level. TFP methods are different than what a pool service uses. You can't mix the two. Stick with us and we can help you keep your pool sanitary and TFP clear (and probably save you some money long term).

 

[phoenixwtc]

Welcome to TFP!

While the Taylor K-2005 is an okay kit, you need to add the K-1515 FAS-DPD test kit to make it equivalent to a K-2006 test kit.
Is your test kit a K-2005 or K-2005C?

Since you have a SWG, youalso need a K-1766 Salt test kit to accurately measure the salt content. While the SWG will show a salt level, it usually isn't the actual salt level of the pool water.

Post a full set of current test results - or at least the ones the K-2005 will provide for now.
FC
CC
pH
TA
CH
CYA
Salt
Water temperature

Have a read thru
Pool Care Basics
Become familiar with
FC/CYA Levels
PoolMath
Overnight Chlorine Loss Test
SLAM Process

Inspiration
How Clear is TFP Clear?

You need to know an accurate CYA level so you can add liquid chlorine to maintain a sanitary pool while you work on your chlorinator issue. After you know the CYA level, use the FC/CYA Levels to determine the needed FC target level. TFP methods are different than what a pool service uses. You can't mix the two. Stick with us and we can help you keep your pool sanitary and TFP clear (and probably save you some money long term).

First, I did order the K-1766 test kit. Should have it Friday. Using the K-2005 kit that I have, here are the results this morning.
FC=2.0, CC=0, pH=7.4, TA=70, CH=440,CYA=60, Salt=3500 (per Hayward remote), and Water temp=86 (per Hayward remote). The pool holds about 19,000 gallons, I just replaced the Hayward T-Cell15 with their new TCELLS340.

I have downloaded the PoolMath app.

The "Check System" alert is on.

Thoughts? Thanks

 

[BDY]

Have you done an overnight chlorine loss test to rule out algae? Nascent algae blooms are invisible.. make sure the cell is turned off for this and you are testing after sundown and as close to before sunrise as you can bear (even a little sun skews it a bit).

Overnight Chlorine Loss Test

If you fail the answer is your chlorine is being consumed… if you pass then you can do the reverse with the cell on 100% overnight to do an overnight chlorine gain test to see if the cell is producing.

 

[BDY]

Pa - chlorine is consumed by UV (sun) and organics. If you do this test without sun and are losing chlorine then the answer is organics and you move to SLAM

SLAM Process

 

[Mdragger88]

First, I did order the K-1766 test kit. Should have it Friday. Using the K-2005 kit that I have, here are the results this morning.
FC=2.0, CC=0, pH=7.4, TA=70, CH=440,CYA=60, Salt=3500 (per Hayward remote), and Water temp=86 (per Hayward remote). The pool holds about 19,000 gallons, I just replaced the Hayward T-Cell15 with their new TCELLS340.

I have downloaded the PoolMath app.

The "Check System" alert is on.

Thoughts? Thanks

The check system light comes on automatically every 500 hours-
You should be able to hold down the diagnostic button on the panel and clear that.
Tell us/show us exactly what hayward system you have.
Your fc is indeed low for your cya
FC/CYA Levels

Get that up in target range with some liquid chlorine ASAP
& do an Overnight Chlorine Loss Test with the cell off to rule out algae consuming your fc.
This test is the most accurate when done with the fas/dpd test (taylor k1515) @proavia mentioned you need.

 

[phoenixwtc]

Sorry for the delay in getting back with the group regarding my questions/problems. I've spent the past couple of weeks getting additional testing equipment, replacing the SWG, and trying to learn as much as I can about the chemistry of the pool.

I downloaded the PoolMath app which has been great for tracking the test results. I've been able to keep the results from my testing, the loan pool store testing, and our pool service's tests. Here is a summary of what we've found.

FC => Has ranged from a low of .2 to a high of 4.4. Last night after the pump shut down, I tested and found the FC at 3.4. This morning it was at 0.2. I added 64 ounces of liquid chlorine this morning and tested a couple of hours later and it was 2.0. I did purchase the Taylor K-1515 test kit for testing Chlorine levels.

pH => Has ranged between 7.5 and 7.8. This morning it was 7.5.

TA has ranged from 60 to 100, though the 100 was from the pool store and something about this reading seemed off as my at home test showed 70. Today it was 60.

CH => Has ranged between 400 and 440 with today at 430.

CYA -> Has ranged between 50 and 75 with today at 75. I added four pounds of stabilizer three days ago.

Salt => has ranged from 3110 to 3500 with today at 3270. This is using a ORAPXI digital salt tester.

Overall, my concern has been that the water has not been crystal clear over the past week or so. It has had a slight cloudiness to it. In addition, the chlorine has dissipated quickly over the past couple of weeks. I have added shock over the weekend, only to see FC very low (near zero) less than two days later.

From what I'm reading on this site, I sense that we have an algae problem, though it isn't green or black around the edges. My pool service tech has said that it could be due to a leak somewhere in the pool that is causing the problem with chlorine. But I feel that if that were the case, I should see it through my water bill since the pool has an auto fill capability. But my water bill has actually come down the last two months, so I'm having a hard time seeing the leak theory as valid.

Lots here for the forum to look at comment on. Any insights, thoughts, help would be appreciated.

19,000 gallon in ground pool with Hayward equipment including a SWG.

Thanks

 

[kellyfair]

You’ve answered your own question about why your water isn’t clear. Your FC isn’t nearly high enough for your CYA, even before you bumped your CYA - look at the chart a couple of posts up.

 

[randytsuch]

Run an OCLT test
If you've been running low or no FC, there might be organics in your pool now.

 

[mknauss]

Last night after the pump shut down, I tested and found the FC at 3.4. This morning it was at 0.2.

Time to follow the SLAM Process

 

[phoenixwtc]

Run an OCLT test
If you've been running low or no FC, there might be organics in your pool now.

If I recall, an OCLT is basically checking the FC at night after everything is shut down and then again in the morning before everything stats back up. I did that last night. At 6:50 yesterday evening, the FC was 3.4 and the CYA was 70. This morning doing just an FC test, I got 0.2. I didn’t check the rest of the numbers until a couple hours later. But I did put in 64 oz of liquid chlorine based on the low FC. Later when I checked everything, the FC was 2.0 and the CYA was 75.

 

[proavia]

Night FC of 3.4 and morning of 0.2 means you failed the OCLT and need to SLAM.

Use the FC/CYA Levels to see what FC levels to maintain based on your CYA of 80 (round up 75 = 80).
Your FC is way to low for your CYA level.

 

[phoenixwtc]

Time to follow the SLAM Process

I tend to agree with the comments here that the FC level is too low. Over the weekend, I added three 13.3 oz bags of shock and four pounds of stabilizer. After that, the FC went up to 4.4. Now using the TFP chart for maintaining FC at an 80 CYA, I need a minimum 4 FC and better yet 6 to 11. My concern is that very quickly - within a day - the FC had dropped to 3.4 and by this morning it was 0.2. So the chlorine is not staying in the pool. Now, when I go to the SLAM scale and at 80 CYA, it is recommending a SLAM level of 31. My question is regarding the 31. Does that mean I should be adding enough liquid chlorine to the water to get the FC up to 31? And then maintain that level of FC until the water is completely clear? I know that might be a stupid question, but I want to make sure I understand what TFP is calling for.

Minor second question. I put in pool details into my signature in my profile. But it doesn’t look like it is getting into my messages. What do I need to get the signature into my messages?

Thanks

 

[mknauss]

Does that mean I should be adding enough liquid chlorine to the water to get the FC up to 31?

yes

And then maintain that level of FC until the water is completely clear?

Yes. Pass the three criteria outlined in the article.

I put in pool details into my signature in my profile.

we can see them. If you are on a mobile device, turn it sideways. the signature will show.
More detail would be preferred. Read mine for an example.

 

[Mdragger88]

Does that mean I should be adding enough liquid chlorine to the water to get the FC up to 31? And then maintain that level of FC until the water is completely clear? I know that might be a stupid question, but I want to make sure I understand what TFP is calling for.

Yes-
So you understand, this is why it was suggested initially to do an OCLT first to rule out organics & no one suggested raising cya yet as it increases the necessary slam fc level

For a successful SLAM Process
you need to continue to MAINTAIN Slam level fc for your cya as often as possible (multiple times per day is best) until you meet ALL 3 end of slam criteria-
You are done when:
CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
The water is clear.
(Crystal Clear w/no algae dead or alive)
Do all the things
*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

 

[pjt]

For the FC test, use a 10 ml sample so each drop is 0.5 FC. Saves time and reagents.

 

[phoenixwtc]

Time to follow the SLAM Process

Am I doing the SLAM process correctly? It seems that I’ve added a LOT of liquid chlorine. From what I saw on the chart, with the CYA I’m at, that means I need to raise the FC to 24 ppm. I started this morning at 2.4. The water is cloudy to start. I’ve added four gallon jugs of liquid chlorine. Is this right? The FC is up to 20.

 

[mknauss]

Have you read the article that is linked?

 

[BDY]

You’ve confirmed the date codes on the chlorine and it’s fresh chlorine?