Chlorine levels keep dropping??

[Jsherman]

Hello. Awesome page by the way!! Looking for some help with my chlorine levels. Pool was finished late August 2015. Always had trouble keeping chlorine levels where they need to be. We recently emptied the pool for an acid wash and polish, and upon refill noticed the chlorinator was full of air after shutting the pump down. Long story short found it to be a leak in the filter housing. After solving that and the chlorinator stays full of water (thought this was the issues). Well now that the chlorinator stays full the chlorine levels keep dropping. My CYA levels are good (about 45), I have approx 65 ppm of borate in the pool, and the usual stuff (stain and clarifier, calcium perfect). I have to shock it almost every other day to keep it at about 3 ppm chlorine. I do shock at night and my water is crystal clear. Even after all this my chlorine almost doesn't show up on my dropper test, and once a week I have tested at pool store where again it's always low. I use Clorox shock bags, and have recently (last week) started using the BBB method. I just dumped half a gal of 10 percent bleach and will check tmrw for chlorine levels. Any ideas why the chlorine level struggles so much. Again I use tricolor picks and run the chlorinator on max with the pool running 7 hours a day. Worried with Houston summer almost here, I will come home to a green pool one day. Thoughts? Questions? Thanks!!!

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Sorry should have mention total alk is right where it should be (110).

 

[Jezza]

Welcome to the forum!

Your battle to keep your FC up indicates a likely underlying algae issue. Just because your water is clear it doesn't mean your pool is algae free.

I recommend you SLAM the pool based on your current CYA level http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl. The emphasis is on the 'Maintain' part.

Just wondering how you were testing your pool water because you need the proper test results from one of the recommended test kits.

 

[kimkats]

I am SO glad you found us!! We can fix your pool and save you SO much money it is not even funny!

I do shock at night and my water is crystal clear. Even after all this my chlorine almost doesn't show up on my dropper test, and once a week I have tested at pool store where again it's always low.

I think I found the major problem Pool stores get the tests wrong more than they do right. With all of the tablets and "shock" you have used I am willing to bet your CYA is sky high. The higher your CYA the more FC (free chlorine) you will need. After a while it will almost impossible to stay ahead of it and you have trouble.

Please, please, pretty please do not go back to the pool store They are in business to make money. How do they make it?? Sell you stuff. How do they sell you stuff? By doing your test kit for "free" and telling you what to buy. You add it then come back for more over and over and over. I HAVE been there, done that! It was so bad I "lost" my first pool due to VERY unbalanced water that ruined my liner

You done the best first step--------finding TFP! Your next step is to get a good test kit. Look in my siggy for the best buy as it has more of the stuff we use on a daily/weekly bases to keep our pools looking like a jewel.

For now will you only use liquid bleach (unscented or such) Just plain bleach like you can get from Target or Walmart. Their store brand is fine. Use about 1/2 jug a day until your test kit gets there.

Kim

 

[Jimrahbe]

Wow!! I've got a couple of thoughts and questions.

1. What made you acid wash a pool that was just built in Aug of 2015?
2. What type of test kit are you using to test your water?
3. Why not stop going to the pool store and stop buying bags of Shock, Clarifier, etc?

I'm sure others with more of an in-depth chemical background will soon chime in, but it sounds to me like your chlorine is either being consumed by the sunlight because your CYA is not near 45 or it is doing its job and being consumed as it is killing algae. The only way to know is to have one of the recommended test kits and to do your own testing and quit going to the pool store.

I suggest that the first thing you do is go to the pool school link a the top of this page and give it a good read. I think after reading Pool School, some of the answers that are sure to follow will make much more sense. Pay particular attention the how to SLAM and How to run an overnight test called OCLT.

Thanks,

Jim R.

 

[tim5055]

With all the shock and tabs you have used I find it hard to believe your CYA is only 45.

Not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. But, what can you do?? We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. To do that you need your own accurate test kit. Order a TF100 test kit. The only other real option for a test kit is a Taylor K-2006. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. Yo need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.

While you wait for it to get delivered, you have a homework assignment. Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

So, welcome to TFP!!

 

[Jsherman]

Thanks everyone.

I I have a Taylor k2005c kit. I just tested my own cya and it's a bit lower then pool store said (mid 30's). I will head to store tmrw to get some liquid cya. i added a gal of 9.8 percent bleach and now the chlorine is showing 10-15 FC and I can't discern the difference of color for total chlorine (assuming this is a good thing as this means low CC) I will let it run all night. Will report back in the am but appreciate the help very much. I think my days at the pool store are done (minus buying acid).

Jim we had it acid washed and polished because it was a substandard plaster job with some hydration and "blotchy" spots. It looks great now.

Already started red on my homework....... I was putting much more faith in the pool store readings (fancy test spinning thing and laptop) then the Taylor test kit I have. That stops tonight.

Thanks for for all the help. I'll reply back in the am.

 

[tucsontico]

Welcome to TFP! First things first, DO NOT add more CYA until you are certain why the chlorine is being used up! Adding more CYA unnecessarily will raise the amount of FC (Free Chlorine) needed to keep the pool algae free! When you can, please post a full listing of your current test results, e.g., pH, FC, CC, CYA, TA, & CH.

Also, get a better test kit! The recommended Taylor K2006C or the TFP XL kit will allow better discrimination of the actual values of FC, etc.

Thanks everyone.

I I have a Taylor k2005c kit. I just tested my own cya and it's a bit lower then pool store said (mid 30's). I will head to store tmrw to get some liquid cya. i added a gal of 9.8 percent bleach and now the chlorine is showing 10-15 FC and I can't discern the difference of color for total chlorine (assuming this is a good thing as this means low FC). I will let it run all night. Will report back in the am but appreciate the help very much. I think my days at the pool store are done (minus buying acid).

Jim we had it acid washed and polished because it was a substandard plaster job with some hydration and "blotchy" spots. It looks great now.

Already started red on my homework....... I was putting much more faith in the pool store readings (fancy test spinning thing and laptop) then the Taylor test kit I have. That stops tonight.

Thanks for for all the help. I'll reply back in the am.

 

[Jsherman]

Sure. I'll post results tmrw am after everything settles out. I'll look up the kit as well. Thanks.

 

[Texas Splash]

Jsherman, I certainly don't want to add to the oberwhelming of info you've already received, so I'll keep my input very short:
1st ... welcome to TFP.
2nd .... Having the right tools (test kit) is everything. However, I don't think anyone mentioned that your K-2005 kit can work (for now) if you augment it with the FAS-DPD portion. (That's the R-0870 power and R-0871 drops). We use it to obtain our specific (and high level) FC readings. Your OTO comparator gives you ballpark, but not nearly as accurate as you need. So if you don't order the entire TF-100 or Taylor K-2006, at least consider the FAS-DPD. You can get it at the same TFTestkits site everyone has been advocating.

Great to have you with us!

 

[Jsherman]

Awesome thanks so much! I was just looking and didn't want to pay for an entire new test kit, when I already have all but one test needed. I will just get the FAS DPD to supplement the kit I already have. Not going to lie, I had to google oto comparator Glad you folks are here, and wish I would have joined this forum months ago..........

 

[tim5055]

Awesome thanks so much! I was just looking and didn't want to pay for an entire new test kit, when I already have all but one test needed. I will just get the FAS DPD to supplement the kit I already have. Not going to lie, I had to google oto comparator Glad you folks are here, and wish I would have joined this forum months ago..........

Pat is correct. With the FAS-DPD test it turns your K-2005 into a K-2006 kit

Here is the individual test you need to buy. I also have the SpeedStir and Sample Sizer. They speed testing and accuracy.

 

[kimkats]

Awesome thanks so much! I was just looking and didn't want to pay for an entire new test kit, when I already have all but one test needed. I will just get the FAS DPD to supplement the kit I already have. Not going to lie, I had to google oto comparator Glad you folks are here, and wish I would have joined this forum months ago..........

Never fear...........TFP is here! :super:

You have already come so far that I am sure it will not be long before your pool looks like a jewel! Just wait until you look out and wonder where you water went! It will be so clear that you will not be able to see it! (It was kind of scary the first time that happened to me!)

Kim

 

[Jsherman]

Good morning all. So here are the latest test results.

Alk is 110
CH is 220
cya is 35
tds is 500
ph is 7.5
fc is 10
tc is 10
again hard to discern the chlorine with my current test kit but for a subjective test it looks like the chlorine has dropped overnight (test color is much less pink). As I can't discern exactly, should I continue slamming for a couple days to make sure all is well?

I ordered the fas DPD last night as well.

How often do you guys/gals add bleach? Also is it reasonable (once I figure out what the heck I'm doing) to use bleach and when away from house for more then a couple days, revert back to trichlor pucks as a backup?

 

[Texas Splash]

During the peak swimming season, we'll typically add bleach everyday. As long as the water is clean and balanced, perhaps needing no more than about a 1/2 gal or so. Easy stuff. Tabs could be used for short-term use if you know your CYA is already low, which for our (hot) region, your CYA is not a problem. You may easily find yourself increasing CYA to about 50 or so as we approach summer if your pool gets full sun. My pool gets blasted by sun & heat all day, so I personally run my CYA between 60-70, but remember .... I have to be very vigilant to maintain my target FC with that higher CYA, otherwise if I ever have to SLAM I go though more bleach. But that's very rare now

Until you get your FAS-DPD portion in the mail, it will be tough to get FC real accurate. I wouldn't do too much at the moment other than maintaining pH and ensuring your FC (color) is nice and bright - at least to where you are comfortable knowing it's at about 5 ppm or so. Once your receive your FAS-DPD, post your FC/CC numbers and we'll go from there. Soon, you'll have this down to a science.

 

[tim5055]

Good morning all. So here are the latest test results.

Alk is 110
CH is 220
cya is 35
tds is 500
ph is 7.5
fc is 10
tc is 10
again hard to discern the chlorine with my current test kit but for a subjective test it looks like the chlorine has dropped overnight (test color is much less pink). As I can't discern exactly, should I continue slamming for a couple days to make sure all is well?

I ordered the fas DPD last night as well.

How often do you guys/gals add bleach? Also is it reasonable (once I figure out what the heck I'm doing) to use bleach and when away from house for more then a couple days, revert back to dichlor pucks as a backup?

Why the pool store test (your K-2005 doesn't do TDS)??

Generally chlorine is added daily. Many here do use pucks for vacations, but you have to keep the CYA under control.

My biggest concern is that you are trying to mix/match our advice with pool store advice. Your TDS results and the statement "Sorry should have mention total alk is right where it should be (110)" lead me to believe this. I can't say this strongly enough - trying to mix pool store advice and TFPC advice won't work! We don't pay attention to TDS as it is just a number pool stores use to scare yo into chemical purchases. Additionally, we find TA at 110 a little on the high site leading to pH rising too quickly.

How much Pool School have you read? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

 

[Texas Splash]

Oh, I see you mentioned SLAMming. Yeah, it's tough to know where your FC is at when just the comparator view. Just do the best you can though. The real (accurate) progress will come when the powder & drops arrive. For now, ensure you have some extra jugs of regular Bravo (HEB) or Great Value (Wal-Mart) bleach on-hand, and you'll be set.

And Tim is absolutely correct ... avoid the pool store like the plague .. unless you need a new pool toy or something. No testing advice.

 

[Jsherman]

Hello again! So I got my kit and here are the readings.

10 ml test. FC 4 ppm. CC 0.5 to 1 ppm. Couldn't tell if there was small amounts of pink so I added two drops to be sure.

25 ml test. Added 17 drops before water was clear. Instructions say o multiply by 2??? 34 ppm??? 2 drops for CC equals ????

please help me understand the 25 ml test results.

Alk is 100
ph 7.6
ch of 220.
Cya of 35

If if I am assuming correctly I have a CC of about .5 to 1, so I should begin slamming again and maintain this time longer?

Thanks for all the help?

 

[Texas Splash]

Okay, so there are a few ways to measure FC depending upon how much solution you have left, or how precise you need to be. For example:
5ml sample, multiply drop count by 1 (used to save on reagent; not as precise) - each drop is an FC level
10ml sample, multiply drop count by .5 (standard method) - Example: 14 drops would be an FC of 7
25ml sample, multiply drop count by .2 (used for extreme precision) - so in your example ... 17 drops x .2 = FC of 3.4. (The decimal point is kind of easy to miss).

I would typically stick with the 10ml sample though to save reagent but still feel confident about my results.

A slightly elevated CC could mean a SLAM. It shows your water is not oxidizing the trash as quickly as it should. I would be prepared to SLAM. How's the water? Is it clear? If you wanted to confirm, you could run an overnight test per the Pool School - Perform the Overnight FC Loss Test (OCLT). If you fail that, you know you have to SLAM.

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Your last CYA was measured at 35 (round-up to 40), so your shock/SLAM FC level would be 16. On regular days with no issues, your daily target is an FC of 5. Always keep the Pool School - Chlorine / CYA Chart page within reach.

 

[Jsherman]

I was thinking that same thing. The decimal is missing on my instructions.

Ok ok so super precise 25 ml method means

FC of 3.4 (17 drops times .2)
CC of 0.4 (2 drops times .2)
TC of 3.8.

If 0.5 CC is cutoff for slamming I gues as you say, I should prepare for a slamming this weekend. Sounds good.

Water is crystal clear.

I I will try the overnight test tonight.

Thanks so much for clarifying the missing decimal!!!

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Yes very helpful little chart.

 

[Jsherman]

Just to update everyone I did two overnight FC drop tests and the FC only dropped by 0.3 and 0.4. I added some bleach and now have 0 for CC. I'll maintain FC as instructed and slam when needed. I think I just didn't have the clarity in the testing methods prior to ordering the added test, and my trichlor tabs weren't adding enough for my pool. Plus I underestimated the natural dropping of FC with daily use etc. just wanted to send a final update and thank everyone for the help and great info. Ready for the first spring and summer with a pool thanks to all of you!