Chlorine drops out on auto but holds on %

Pool will not hold chlorine level when set on automatic regardless of the ORP set point. When set on % pool will hold and even generate chlorine. Pool construction company has been attempting for 2 months to rectify but has thus far failed. Hayward suggested lowering the CYA from 60 to 25 by partial drain down. Tested sense and dispense. Replaced SWG. shocked several times and would hold on percentage but not on any ORP setting. FCL 5.70 TCL 5.69 PH 7.4 ALK 72 CH 131 SALT 3100. Set ORP on 650Mv and chlorine drops to 4, next day 2, following day 1, then zero. Hayward rep tests system and water and states that it is OK. Pool construction company says next they will try massive shock. Several smaller shocks did help but did not solve problem. Pool showed some green color when first filled but they fixed it somehow in short order. Within a week scale formed and they dumped in 4 gal MA and that was solved. Next pool went on free service for aprox 10 weeks. Purchased a good test kit and started tracking chemistry. When chlorine began dropping out I asked pool service people and they stated it tested OK. When free service ended I went to pool store and they wanted me to super chlorinate then add salt, sodium bicarbonate,CYA. So I tried to get chlorine up with super chlorination as pool began clouding up, then I called the construction company and they began their 2 month attempt to have the pool operate on automatic. Pool is now on 90% and chlorine has risen from 1 to 4. Now they say they want to shock again. (I am unclear if they ever shocked my pool hard enough or long enough in the past, but the water looks good) I said to them that I am getting frustrated and am about ready to drain the pool. They liked that idea, but perhaps I should allow them to do a massive prolonged shock to oxidize any possible organic organism before I pay to drain refill and rebalance.
 
Now they say they want to shock again. (I am unclear if they ever shocked my pool hard enough or long enough in the past, but the water looks good) I said to them that I am getting frustrated and am about ready to drain the pool. They liked that idea, but perhaps I should allow them to do a massive prolonged shock to oxidize any possible organic organism before I pay to drain refill and rebalance.
My, you were up late worrying about this....

Well you will find that we differ from most pool stores and pool professionals as to how to maintain a pool. They usually want 3" tabs and powered shock while we don't like the long term effects of those as it adds to the stabilizer level in the pool (also called CYA). Elevated CYA levels cause other problems down the road.

Now, before we start to go down this road I have a couple of questions.

First, are you going to continue to maintain the pool or will a service take care of it? The reason I ask is that as I said, our advice and pool store advice are different. If you try to mix their advice and TFPC advice it won't work and you will get more frustrated than you are now. If you say a service will take care of it, just follow their instructions. You can stop reading now.

If you are going to maintain it then keep reading.

You say you "Purchased a good test kit and started tracking chemistry". What kit is it? To follow our methods you need to have one of the recommended test kits. You can buy a kit at a pool store, but again the pool store kits generally won't cut it. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. All these kits contain that test while very few other kits do. Tell us what you have. You may only need to add a little bit to what you have to equal one of the kits we recommend.

Post a full set of results from your test kit.

We would like to see:
Free Chlorine = FC
Combined Chlorine = CC
pH
Calcium Hardness = CH
Total Alkalinity = TA
Stabilizer/CYA = CYA

With those numbers we can point you in the right direction down this path.

You also say they want to do a "massive prolonged shock to oxidize any possible organic organism". To be honest that sounds like what we teach, as long as they are using liquid chlorine NOT powered shock. Again, we go back to controlling the stabilizer level which powered shock will add to the pool. We do not "shock" our pools, we follow the SLAM Process when there is a problem. Read thorough these instructions and I think you will understand.

If you stumbled across our little piece of the internet at 1:30 in the morning you are goin gto say, not much but how much Pool School have you read? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool


If So, welcome to TFP!!
 
Thanks for responding. I intend on maintaining my own pool however, as the pool is relatively new and under warranty, I am attempting to have it corrected by the well experienced builder, (perhaps 500 pools annualy) and the equipment supplier (Hayward). What I have thus far experienced regarding maintenance, is the pool boys have limited experience and typically poor work ethics. It is my opinion that it was during this service that the pool was only maintained on the ragged edge of balance.

The test kits that I own are a LaMotte color Q pro-7 digital unit (www.lamotte.com) for free chlorine, total chlorine, bromine, Ph, alkalinity, calcium hardness, and Cyanuric acid. I also have a Taylor drop kit for testing salt. The Hayward pro logic controller also agrees with my independent testing as well as the Taylor tests that the pool contractor performs. I do find slight deviations between the various testing methods but find them all to be within what I consider acceptable ranges. The only exception is the pool store which is obviously interested in selling product.

The pool contractor does use powdered shock. The last shock only brought the chlorine level to around 8 and within 24hrs dropped to around 4 after a 6 lb treatment. Prior shocks were less than 6 lbs. I am not sure why you are opposed to powered shock. As long as the stabilizer (CYA)is monitored. Note that the equipment mfgr. Had us lower the stabilizer down to around 25 or 30ppm.

I have read thru your pool school, ABC's, Recomended chemicals, how to chlorinate your pool, etc. I have purchased several books to familiarize my self with pool maintenance, and have spent considerable time reading posts on TFP.

Remember, the pool remains under warranty, so I am kind of stuck with their procedures. The problem remains near zero ORP chlorine production and the question is to slam or drain. The contractor jumped at my suggestion to drain as it takes out of the equation whether anything odd ever was introduced to the pool. However, they will not pay for the water. Labor and chemicals have not been addressed. Indirectly they are maintaining the pool was fine when they turned it over to me, and my records indicate that it was not. After reading all night, it seems that slam may work and will give me leverage. If it does not, then the onus to continue with other options remains on their shoulders.
 
While a few here report acceptable results from the ColorQ it is generally regarded here questionable. Here are a couple of posts:

duraleigh is correct, the ColorQ is generally very good at FC, CC, and PH. Reasonable at TA. Shaky on CH, and questionable on CYA. However there are occasional reports of more dramatic problems that appear to be related to the occasional defective unit.

I have the color Q as well and am VERY disappointed. I just got the DPD/FAS test from TF and it shows my FC to be 6 higher than what the ColorQ has been telling me. My Taylor K2006 confirmed the DPD/FAS results. The only thing that the ColorQ seems to get right is the TA. I ordered the ColorQ because i am not very good at matching the colors and I'm sorry I did. Was thinking my FC levels were OK and weren't even close!

Man, I'm really bummed. I've been using a ColorQ Pro 7 for a few months as I put my new pool online and just found out today that it's giving me bogus readings. They may be consistent, but they are waaaaaay off.

It says my PH is 7.3, it's really 8.4 (ouch)
It says my FC is 1, it's really 3.2
It says my CH is 150, it's really 130
It says my ALK is 150, it's really 100

Ironically, the reason I now know this is that I installed a PH probe today (chemlink system), and the initial reading was 8.5. I thought the PH was 7.3, so I figured the probe was DOA. Before I RMA'd it, I got the water tested by the pool store.....and woah...glad I did that.

Amazing that it's so poor. I saw several threads here that recommended the unit (thought peppered with skeptics who I should have listened to).

So now I'm looking for a better test kit... :)

I have had a Lamotte ColorQ Pro 9 Plus and a TF100 for 3 years. I test with the TF-100 weekly and the ColorQ every few weeks. Here are some of differences I have noticed.

FC - ColorQ always has a much lower value
(ex. 5.0 on TF100 and 1.13 on ColorQ. I know what FC was yesterday plus chlorine added never adds up to the ColorQ low numbers.)
CC - ColorQ does not test for this
TC - ColorQ is always the same as FC, always.
PH - ColorQ is good here, usually the same as I got with the TF100.
TA - ColorQ is about 30 lower that TF100. Why do I think the TF100 is correct? With a copper problem we do a 1/4 drain once or twice a year. I test using both test kits, drain, test again + add baking soda. The TF100 number in the end is where I should be, the Lamotte numbers are all over the place.
CH - ColorQ much lower again. (ex TF100 tests 200, ColorQ tests 55 - always a huge difference on this one)
CYA - ColorQ lower here as well and this one is never consistent. It could read 55 one week and 32 four days later where no water is lost or added. (ex TF100 80, ColorQ 55)
COP - Copper, The reason I purchased the ColorQ was testing copper and I thought the TF100 would be too difficult to arrive at proper results, especially the CYA. Copper is always at least .3 sometimes .7. I tested bottled water one day, it tested .3

The TF100 readings are accurate. I have 3 years of testing logs with both test kits that I am referring back to. I always know my current water results and when I factor in the chemicals added or the water I have added/lost, I can always get my pool balanced with the TF100.

At this point I still test with my ColorQ because I have it. I replace reagents every year as obviously I like to test. My pool is salt but with the massive rains we have had this year I went to clorox during the spring/summer. We had 15" of rain on July 27th and 8" the next day, the entire pool season was rainy.

Since I have never had a green or cloudy pool, I will assume my TF100 is giving me good numbers. I wanted the ColorQ to work because it is easy. I easily schooled myself on CYA readings on this forum. The only accurate number I feel I am getting from my ColorQ is my PH reading. With the ColorQ 9 costing close to $200, I have basically paid $200 for reading PH tests.

We promote drop based testing with Taylor reagents. Their accuracy has been proven time after time. I'll leave it at that as it is your choice.

I understand the need to follow the pool builders guidance for warranty purposes. You are correct on the work ethic and experience/abilities of the "pool maintenance technicians". They are generally trying to get by with limited knowledge and doing the least amount of work they can.

We are really not opposed to any of the pool chemicals, other than the fact that most have a "generic" equivalent you can purchase at WalMart rather than the inflated prices the pool stores want to charge. You are correct that there is nothing "wrong" with solid chlorine products as long as their use as you say is monitored. The problem is that traditional pool wisdom says that the free chlorine levels are to be kept at the same level no matter what the amount of CYA in the water is. They ignore the relationship between the two. This relationship has been know for over 20 years but the pool industry ignores it. What level of chlorine is being recommended to you and do they even discuss it's relationship to CYA?

Post a full set of reading please....

I will close with a quote from the owner of this site
Throughout TFP, you will read that we suggest certain levels that good science and practical experience has taught us fall within safe ranges.

Further reading of posts here will draw you to the inescapable conclusion that these guidelines work.......in thousands and thousands of pools worldwide.

You may or may not choose to use these methods and guidelines or you may use some and not others. Our goal is to teach you what has been proven time and time again and then let you use that information to your benefit.
 
The equipment rep (Hayward) tested my water and included nitrate test. Results were within limits. He then tested all of his equipment and found it to be in working order. So he set the ORP and said not to worry unless ORP drops below 500. It did not. However, chlorine dropped from 4 to 1 within 24 hrs. The ORP has already been replaced, along with the SWG. As I understand the program: when on %, the SWG runs whatever % of the time for which it is set during a three hour cycle. ORP however measures Mv based upon conductivity of the salt water and is constantly balanced to need for chlorine automatically. It would seem foolish to ignore this feature of automation after paying for it.
 
Since I have been testing with both the LaMotte and the builder is testing with Taylor, I have been able to draw relative comparisons between measurements. For example:if I test CYA LaMotte @ 30 and the builder tests with Taylor @40, and the pool store tests @35, I have established a relationship between each test. IMHO none of the test kits by themselves are particularly accurate. Therefore frequent testing and careful notation will establish known relationships.

As of 9/24/14 LaMotte test results were:
FCL4.02
TCL4.11
PH7.5
CH146
ALY72
CYA25
Salt 3000
These test results remain fairly static except chlorine when set on ORP (36 hours drops to 0.1 which is about what the tap water reads. Once this occurs the water begins to lose clarity, so the contractor shocks with 3 or 4 lbs of dry shock. I doubt if they are using Lithium Hypo, but I don't know. Or they have placed 2 tabs in the skimmer, which I have questioned.
Regarding chlorine, the pool contractor asked me what I wanted, and after some consideration selected 4.0 as my target. Regarding CYA the pool contractor did not know prior to consultation with Hayward that they recomend a level around 30 with SWG and sense & dispense. As I understand it, that is going to require the SWG to work harder since the water will be less stabilized.
 
The ORP controller has been tested by Hayward and found to be working properly.
This indicates to me that there is something potentially in the water consuming the chlorine.
Perhaps the pool is in a chlorine demand situation, potentially created by an undocumented treatment for algae early on which was not totally successful.
 

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Since I have been testing with both the LaMotte and the builder is testing with Taylor, I have been able to draw relative comparisons between measurements. For example:if I test CYA LaMotte @ 30 and the builder tests with Taylor @40, and the pool store tests @35, I have established a relationship between each test. IMHO none of the test kits by themselves are particularly accurate.
I don't know wht the pool store used, but I would trust the builders numbers if he is using a Taylor based test kit. They have been proven by many people here as extremely accurate when used properly.

OCLT test indicated a drop of 0.77 Free chlorine @6pm 9/28 was 4.59 Free chlorine @8am was 3.82
Well, anything less than 1.0 drop is considered a pass so it indicates little or no chlorine demand form organics.
 
Pool contractor added 8lbs shock this morning. Said they will return tomorrow and add 6lbs more, and make decision on wheather to continue with additional treatment.

I checked what they added and it is sodium hypochlorite @45%.

System has been set on 90% over the weekend.
LaMotte tested FCL @ 4.59
Taylor tested FCL @ 6
I just ordered a TF100. Might as well have a third set of numbers.
 
Might as well have a third set of numbers.
I k now many people do that but I can't understand why. Do you take an average?

Time and time again the drops based Taylor chemistry (as in the TF-100 and K-2006) has proven to be the most accurate and I see no reason to be confused and perhaps mislead by an inaccurate test.
 
What they added was almost certainly dichlor. This is going to raise your CYA. 14 lbs will raise it by 60 in your 14K gallon pool, not to mention plummet your pH..
Powered shock is easy for the builder to use. At this point with the previously reported CYA you can figure it is now over 100. At least a partial water exchange is going to be necessary.
 
Well... to be fair it could also have been cal-hypo which would be much less detrimental as it would only raise your CH a bit (+40). This emphasizes the importance of testing with a drop based kit and knowing exactly what's going in your pool and why.
 
The builder added 45% sodium hypo. 8lbs then perhaps 5lbs 24 hours later. Chlorine levels 24 hours after the first dose rose to and remained fairly static around 17. This morning 24 hours after the second dose chlorine levels are around 16 LaMotte and 20 Taylor. CYA tests 13 LaMotte and 0 Taylor. Ph has not been a problem with the acid dispense. Builders tech said he would check back in the morning. SWG had remained on 90% throughout. Not sure how CYA level got so low, we have had rain run off, but not excessive amounts. Pool is sparkly clear. Nothing living in there right now, including swimmers.
 

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