We’ve had cold temps, so this is the latest I have ever opened my pool(I assume algae still multipled exponentially with the sun?). I use a tarp to cover my pool during winter and I skimmed it for leaves and shocked the above tarp water before taking the tarp off. Above water tarp turned diarrhea brown, so I assume metals were in water? Below tarp was green(not usually like that in the past). Anyways, we were at high phosphates at the end of last season, but we were able to stay algae free, so I never worried about that level. I tested the water before adding any chlorine and my PH was 7.6 and I can’t remember the numbers for stabilizer, alkilinity, etc, but everything was in normal range. I have around a 28,000 gallon pool, and after adding 12 gallons of 12.5% chlorine over the course of 3 hours with an absolute zero free chlorine number still, I need opinions on what to do next. When I switched from baquacil to chlorine, I just kept shocking and it worked, but I’m now at the same amount of shock I used when I converted many years ago, so I’m wondering if something else is going on(I usually only use between 5-8 gallons for start up every year). My pool is worse than pond green. Lakes are clearer than the green that was in my pool. Since the top water turned brown, I’m wondering if there is something with the metals, but would that effect the free chlorine readings? I’m also wondering if I should add phosphate remover in the morning before resuming shock therapy? Or, should I just keep dumping chlorine in until I get a FC reading?
Opening pool and no free chlorine
- Thread starter Theevilfrog
- Start date
- Jun 22, 2014
- 47,965
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
Sounds like you have a few things to manage with the water, but killing the algae will probably be first. But let's confirm a few things first that we need to know:
- How are you testing the water? Which test kit?
- We need to see a full set of test results; preferably from a TF-100 (Link below) or Taylor K-2006C test kit. See Test Kits Compared
- Are you on a well? That would explain the brown when you added chlorine to the water (iron).
- Phosphates are usually a non-player for well-sanitized pools. Only when there is algae present do phosphates enhance the algae (food). But if you kill the algae and keep it away, phosphates are irrelevant.
- Please update your signature with all of your pool and equipment info.
At this point, I wouldn't add anything to the water except chlorine (regular bleach) until we see a full set of results. This way we can confirm what you should do next. Thanks for posting!
Sounds like you have a few things to manage with the water, but killing the algae will probably be first. But let's confirm a few things first that we need to know:- How are you testing the water? Which test kit?
- We need to see a full set of test results; preferably from a TF-100 (Link below) or Taylor K-2006C test kit. See Test Kits Compared
- Are you on a well? That would explain the brown when you added chlorine to the water (iron).
- Phosphates are usually a non-player for well-sanitized pools. Only when there is algae present do phosphates enhance the algae (food). But if you kill the algae and keep it away, phosphates are irrelevant.
- Please update your signature with all of your pool and equipment info.
At this point, I wouldn't add anything to the water except chlorine (regular bleach) until we see a full set of results. This way we can confirm what you should do next. Thanks for posting!
I have city water. It rained a lot this winter(not sure if that makes any difference). I will just shock some more and hopefully start seeing a FC number. Thanks. I needed some reassurance to keep shocking. Hopefully, I won’t be back on this thread posting my new full set of numbers...cross fingers.
That's really not what he said to do...
We never advise someone to just keep dumping something in to their pool blindly. He said that the water needs tested with a reliable kit and dosed based on those test results. We don't even give advice without numbers to base that advice on, so "keep shocking" was certainly not advised.
To clarify: Texas' final line was saying not to make adjustments until reliable test results are obtained, excepting for a small amount of chlorine that will keep things from going backwards too much while waiting on those test results. Absolutely, positively was it not advised to dump chlorine until the problem goes away.
We never advise someone to just keep dumping something in to their pool blindly. He said that the water needs tested with a reliable kit and dosed based on those test results. We don't even give advice without numbers to base that advice on, so "keep shocking" was certainly not advised.
To clarify: Texas' final line was saying not to make adjustments until reliable test results are obtained, excepting for a small amount of chlorine that will keep things from going backwards too much while waiting on those test results. Absolutely, positively was it not advised to dump chlorine until the problem goes away.
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Totally confused now. If I continue to have a zero free chlorine reading after each time I put shock in, I shouldn’t keep shocking until I can get a free chlorine reading? I thought a zero free chlorine reading tells me that my chlorine is being used up/converted to CC and has little to none sanitizing ability then. My pool is very green still, but looking better than the dark green sludge algae I had yesterday. I feel that I need to keep shocking until I can get a free chlorine reading. How is a little chlorine in my pool going to prevent me from going backwards if I can’t get a FC reading? You should’ve told me the TC, CC, FC number I need to keep my pool from going backwards. A small amount of chlorine? What is that even? Umm, yeah, I’ve been testing. My numbers are fine except for free chlorine and high phosphates. I know about stabilizer numbers, ph, Alk, etc. I‘m just not familiar with if phosphates come into play and if metals could effect shocking, hence, why I posted asking if I need to do something different than what I’ve been doing for the past 30 years. Not a complete idiot here.
- Jun 22, 2014
- 47,965
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
What you're experiencing here is a bit of what I would refer to as a "TFP-transition". It's normal as a new member. Pool owners do their own thing for years getting-by or using outside agencies to test their water, then one year - BAM! Nothing works. The reason just shocking or adding chlorine blindly isn't advisable is because without accurate test results of all items (FC, CC, CYA, PH, TA, CH) we can't put the whole scenario together. We know from experience that in Ohio and many others areas just opening this time of year, water chemistry can do odd things like never before based on temperature and previous chemicals added at closing. It requires "specific" chlorine treatments based on accurate testing of all levels to know what to do next. Just adding high levels of chlorine may only change the water color slightly and/or drain your checkbook. We rely on those accurate TF-100 (or Taylor K-2006C) test results to avoid all that. No guessing, no extended periods of effort lost. Chlorine is the way, but only in the proper amount based on the other items mentioned.
Pool opening(evening)
PH 7.5
Alk 90
TC 0
FC 0
CYA 0-5 (black dot test...really couldn’t see it after adding small amount of water, so while no one will believe me, it’s a zero in my book). FYI: I’ve kept my CYA numbers lower than recommended around 15-30ppm at this location for 12 years with hassle free pool all season. Pool in Florida requires higher CYA for hassle free.
After 1st day shocking repeatedly(testing in between applications) in evening(after sun went down) using a total of 12 gallons of 12.5% chlorine.
PH 7.2
Alk 80
TC 1.4
FC 0
CYA 0-5
Next morning my PH was 7.0, so I added to bring my PH up. I decided to hold off on stabilizer as it was rainy and very cloudy in addition to being concerned that I have ammonia that will eat it anyways. I shocked again with 8 gallons of 12.5% chlorine(testing in between). Here’s my new numbers.
PH 7.4
Alk 80
TC .7
FC 0
CYA 0-5
I’m out of chlorine or else I would’ve hit it again this evening. It’s supposed to be cloudy and rainy again tomorrow, so I’m thinking of delaying adding my liquid CYA as I have such a high chlorine demand and do not see any benefit from adding it if I have ammonia right now. I know you advised against shocking the Crud out of the pool, but based on my numbers, I feel that is the only plausible solution right now. I feel I am getting closer with my FC to TC ratio by shocking.
PH 7.5
Alk 90
TC 0
FC 0
CYA 0-5 (black dot test...really couldn’t see it after adding small amount of water, so while no one will believe me, it’s a zero in my book). FYI: I’ve kept my CYA numbers lower than recommended around 15-30ppm at this location for 12 years with hassle free pool all season. Pool in Florida requires higher CYA for hassle free.
After 1st day shocking repeatedly(testing in between applications) in evening(after sun went down) using a total of 12 gallons of 12.5% chlorine.
PH 7.2
Alk 80
TC 1.4
FC 0
CYA 0-5
Next morning my PH was 7.0, so I added to bring my PH up. I decided to hold off on stabilizer as it was rainy and very cloudy in addition to being concerned that I have ammonia that will eat it anyways. I shocked again with 8 gallons of 12.5% chlorine(testing in between). Here’s my new numbers.
PH 7.4
Alk 80
TC .7
FC 0
CYA 0-5
I’m out of chlorine or else I would’ve hit it again this evening. It’s supposed to be cloudy and rainy again tomorrow, so I’m thinking of delaying adding my liquid CYA as I have such a high chlorine demand and do not see any benefit from adding it if I have ammonia right now. I know you advised against shocking the Crud out of the pool, but based on my numbers, I feel that is the only plausible solution right now. I feel I am getting closer with my FC to TC ratio by shocking.
- Jun 8, 2019
- 4,576
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
If you are burning through that much chlorine it very well could be ammonia. Do you have a DPD-FAS test kit? The remedy is to either do a big water exchange to dilute the ammonia or lots of chlorine, but in measured doses. Add enough for 10ppm of FC to the pool, let mix 15 mins, test FC. Add enough to get to 10ppm, mix 15 minutes, test FC, keep repeating until you can hold FC after 15 minutes.
Just be careful with the additions. It’s a process. If you overshoot you could end up with way too much FC and damage your pool.
Just be careful with the additions. It’s a process. If you overshoot you could end up with way too much FC and damage your pool.
Is this a misprint? this is the opposite of the black dot test i'm familiar with, that is, if the dot is obscured with just a little sample added to the tube, that is high cya.
just checking.
Omg...yes. Good catch. I wrote that wrong. I had watched a YouTube video to double check that I’m performing it correctly to make sure it was zero and not high and well, my brain cannot multi-task(I wrote their issue, not mine...mine was opposite..lol).
Update for anyone that reads this: I did vacuum bottom to waste one more time which depleted about 6 inches of water(not a huge amount of water replacement). It took 6 more gallons, but I FINALLY reached my FC shock level. By the 3rd gallon, you do not know how happy I was to see a chlorine reading when I tested 30 seconds after I put it in. It was completely gone 10 minutes later, but I knew I was getting there(yeah, I might over test a little...poor in a gallon, test where I just put it in at, wash sides and bottom, retest again and repeat with next gallon). Note to self though: I’m buying an ammonia test kit for next year to check before opening. It’s the only thing that I can think of that called for such an extremely high chlorine demand. Never been through anything like this before. Thanks everyone.
Update for anyone that reads this: I did vacuum bottom to waste one more time which depleted about 6 inches of water(not a huge amount of water replacement). It took 6 more gallons, but I FINALLY reached my FC shock level. By the 3rd gallon, you do not know how happy I was to see a chlorine reading when I tested 30 seconds after I put it in. It was completely gone 10 minutes later, but I knew I was getting there(yeah, I might over test a little...poor in a gallon, test where I just put it in at, wash sides and bottom, retest again and repeat with next gallon). Note to self though: I’m buying an ammonia test kit for next year to check before opening. It’s the only thing that I can think of that called for such an extremely high chlorine demand. Never been through anything like this before. Thanks everyone.