Unexplained FC Consumption - SOLVED - although the Mystery Remains

[toofast]

Re: Unexplained FC Consumption (updated title)

ok i confess, each time you go away i come over and pee in your pool LOL
i hope you still have your sense of humor intact
with the amount of bleach you are adding are you having to drain the pool?
if the pool is covered and not used while you are away you should have very little chlorine loss regardless of CYA
do you have an antifloat valve in the bottom of the pool. not sure what it is correctly called
i have one in mine and it was explained to me that if water pressure under pool was higher than inside it would allow water from underneath to come into pool
are you on town sewerage or septic system.
do you have one of the new treatment plant type septic systems and if so where are the sprinkler jets in relation to the pool
my latest suggestion is to manually dose pool to high level and then completely turn off pump and stenner for a couple of days and see what happens
i relly feel for you, i wish i was there to try and help in person

I have no choice but to keep my humor, although it is dwindling quickly...I honestly thought next time I am home I will just winterize and put her away for the year.

I do not have the valve on the bottom of the pool...it is 100% fiberglass shell. I do have a sump pit on the deep end to control ground water if/when I have to drain.

I have manually dosed the pool quite a few times (when home) to see if the stenner was acting up and no change.

I do have a septic system (engineered mound) but once again no sprinklers and no way for water (other than rain) to get back into the pool.

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Do you have the pump/filter on a timer?

Yep my pump/filter and stenner are all on timers.

 

[FirstPoolLastPool]

Re: Unexplained FC Consumption (updated title)

Wow, what a journey!

I apologize if you have had any of these points raised before, but what about

* keeping your pump running on the higher speed at all times and see if your pattern changes?
* was your pump running on low speed overnight when your cl loss was low and was it on high during day when you used up cl like crazy?
* could there be an area in the plumbing that grows something bad when the pump is slow GPM and then re-introduces it when speed goes up?
* are winds high during the day and could they be blowing pollen or other organic matter into pool?
* what is your overflow drain set up like for pool itself and nearby decking? could there be something in the pipes that "sloshes" back in during day?
* have you tried using skimmer socks and checking them in morning and night to see if something is blowing in and accumulating at certain times?
* have you tried entering all your data into spreadsheet and graphing the results to see if a visual display allowed a pattern to emerge that you might not be seeing?

 

[Daltex]

Re: Unexplained FC Consumption (updated title)

Read the whole thread and sorry about your struggles. I'm having similar issues to a lesser extent.

Just checking the facts so far:

-Did you get the test sample for the CYA?
-You pass the OCLT and lose massive ppm of FC during the day with the pool at the same condition as OCLT testing such as pump speed, cover same as OCLT on or off, etc. ?
-Did you ever try and run FC up to MS level and check OCLT?
-Contact pool manufacturer to see if light has a niche behind it?

 

[Butterfly]

Re: Unexplained FC Consumption (updated title)

Yep my pump/filter and stenner are all on timers.

Does the pump/filter run at night?

 

[toofast]

Re: Unexplained FC Consumption (updated title)

Does the pump/filter run at night?

Not normally....except when doing my OCLT.

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Read the whole thread and sorry about your struggles. I'm having similar issues to a lesser extent.

Just checking the facts so far:

-Did you get the test sample for the CYA?
-You pass the OCLT and lose massive ppm of FC during the day with the pool at the same condition as OCLT testing such as pump speed, cover same as OCLT on or off, etc. ?
-Did you ever try and run FC up to MS level and check OCLT?
-Contact pool manufacturer to see if light has a niche behind it?

Yep long thread so all good questions.

No on the CYA test, other than my neighbor who knows how to test for CYA got similar results, so I assumed I am good at my current 30 level. (will be boosting to 40)

Yes to the significant loss of FC during the day...similar conditions, etc.

No, I did not try and run it up to Mustard Algae Shock Levels, guess that is a viable option for sure.

I do have a light niche, and I've unscrewed it and vacuumed all the water out and replaced it with fresh water, never had signs of algae though.

 

[toofast]

Re: Unexplained FC Consumption (updated title)

Wow, what a journey!

I apologize if you have had any of these points raised before, but what about

* keeping your pump running on the higher speed at all times and see if your pattern changes?
* was your pump running on low speed overnight when your cl loss was low and was it on high during day when you used up cl like crazy?
* could there be an area in the plumbing that grows something bad when the pump is slow GPM and then re-introduces it when speed goes up?
* are winds high during the day and could they be blowing pollen or other organic matter into pool?
* what is your overflow drain set up like for pool itself and nearby decking? could there be something in the pipes that "sloshes" back in during day?
* have you tried using skimmer socks and checking them in morning and night to see if something is blowing in and accumulating at certain times?
* have you tried entering all your data into spreadsheet and graphing the results to see if a visual display allowed a pattern to emerge that you might not be seeing?

I have NOT run my pump on high for long hours, but was thinking of that idea.

Pump is normally on LOW during OCLT and during normal day operations, only on high when vacuuming

I do have wind during the day and yes "dirt" does blow into the pool (or at least it looks like dirt) -- could good old regular dirt contain enough "junk" to eat that much FC during the day...if so then why at night does it become dormant ?

All my data is charted and graphed and that is what caused the alarm in the first place, a drastic change in FC this year compared to last year and NO changes that I can observe.

No overflow drain issues..

As for socks, yes actually when I still had the glass media I used 1 micron filters to catch the dirt the glass did not, now that I replaced with new sand - no issues. Keep wondering if my lack of filtering ability had some build up of resilient algae, and I just need to SLAM for 4,5, 6 days in a row ?

 

[SunnyOptimism]

Unexplained FC Consumption (updated title)

Any chance you can pay a neighbor kid some money to come over and dump jugs of bleach in the pool while you're away?

You indicate that you travel a lot and cover up the pool while gone. Your pool water temps must soar to very high levels during those periods. That would be ideal conditions for lots of anaerobic bacteria to grow and for temperature related FC loss, ie, high temps plus low O2 levels.


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[aussieta]

Re: Unexplained FC Consumption (updated title)

similar to what firstpoollastpool was getting at
i meant turn off the pump in case that was intrducing the mystery substance
do you have a dog that has access to pool

 

[toofast]

Re: Unexplained FC Consumption (updated title)

similar to what firstpoollastpool was getting at
i meant turn off the pump in case that was intrducing the mystery substance
do you have a dog that has access to pool

Oh...no dog, the pool is 100% fenced and nothing but small stuff could even think about getting in.

I could turn off the pump for sure during the day next time I am back to see if that has an impact, but I am at a loss as to how the pump itself could be introducing stuff.

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Any chance you can pay a neighbor kid some money to come over and dump jugs of bleach in the pool while you're away?

You indicate that you travel a lot and cover up the pool while gone. Your pool water temps must soar to very high levels during those periods. That would be ideal conditions for lots of anaerobic bacteria to grow and for temperature related FC loss, ie, high temps plus low O2 levels.


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Ok, this is new info to me...but the pool "rarely" gets above 90 degrees even if covered for 3-4 days straight, is that enough to cause the problem you mentioned ?

As for the neighbor kid adding bleach...once again, I have automation via the stenner pump, I can inject 4-5 gallons a day while gone, which I have at times. The pool just eats of the bleach and laughs at me.

 

[SunnyOptimism]

Unexplained FC Consumption (updated title)

Oh...no dog, the pool is 100% fenced and nothing but small stuff could even think about getting in.

I could turn off the pump for sure during the day next time I am back to see if that has an impact, but I am at a loss as to how the pump itself could be introducing stuff.

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Ok, this is new info to me...but the pool "rarely" gets above 90 degrees even if covered for 3-4 days straight, is that enough to cause the problem you mentioned ?

As for the neighbor kid adding bleach...once again, I have automation via the stenner pump, I can inject 4-5 gallons a day while gone, which I have at times. The pool just eats of the bleach and laughs at me.

90 is high, but not disastrously high. I live in the SW and if I left my pool cover on for days on end during the high heat months, my pool water could easily get to 105-110F. My pool builder was quite adamant that I not use the pool cover during the summer months otherwise Id have greater risk of an algae bloom due to hotter water.

Is 4 to 5 gallons enough to maintain a Shock level of FC? When I SLAM'ed my pool recently, I had to dump in gallons of bleach all at once and keep it up in order to get to shock levels of FC and hold it there. A Stenner pump, like an SWG, is good for maintenance dosing but they can rarely inject enough FC fast enough to get to SLAM level and hold it there.

Also, you mention 5% bleach a lot. Can you get it higher, like 10% or 12%? Might save you the trouble of adding so many bottles.


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[toofast]

Re: Unexplained FC Consumption (updated title)

90 is high, but not disastrously high. I live in the SW and if I left my pool cover on for days on end during the high heat months, my pool water could easily get to 105-110F. My pool builder was quite adamant that I not use the pool cover during the summer months otherwise Id have greater risk of an algae bloom due to hotter water.

Is 4 to 5 gallons enough to maintain a Shock level of FC? When I SLAM'ed my pool recently, I had to dump in gallons of bleach all at once and keep it up in order to get to shock levels of FC and hold it there. A Stenner pump, like an SWG, is good for maintenance dosing but they can rarely inject enough FC fast enough to get to SLAM level and hold it there.

Also, you mention 5% bleach a lot. Can you get it higher, like 10% or 12%? Might save you the trouble of adding so many bottles.


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So to be clear, I've manually SLAMMED quite a few times, pass OCLT many many times and many nights in a row, only to continue to see my FC beating consuming like crazy.

As for the cover...that is still an area I am confused on. Last year I had the cover on exactly the same way, and always consumed 2 PPM or less on most days, and had a clear pool. Now what changed...

 

[FirstPoolLastPool]

Re: Unexplained FC Consumption (updated title)

You have covered so many possible explanations we are into the realm of the unknown so to speak and I am trying to act like Sherlock here and think about what is different during the day because that is when you are losing all your CL. Of course the sun is out and we know about sun and how fast you can lose CL BUT what intrigues me most id your recurring lament as to "what is different this year!" I feel really bad for you and very sympathetic. So here is my latest wild hare of an idea.....

What if there is a physical (as opposed to chemical) difference this year and it only occurs during the day. If the physical difference affected water flow dynamics it could have some interesting effects on circulation and chlorine concentrations and algae control. What if something has changed with the fluid dynamics compared to last year and it only matters or happens during the day?

My half-baked idea says maybe something happened to restrict or impair water flow since last year. Could be an obstruction in a return line, filter media clog somewhere, slight impeller damage, or even something electronic affecting RPM'S which could affect GPM's. What I am getting at is what if GPM flow in some parts or all of your plumbing is different this year?

Furthermore, what if that difference is most noticeable when pump is on and running at the speed you normally use during the day? If this were true, it MIGHT explain why you have passed OCLT but go through chlorine like crazy during daylight hours. I know this is really a stretch and possibly just another rabbit hole but we are at the point of looking into odd corners and strange explanations here aren't we since you have already tried SO many things.

So, how could you begin to test for something like what I suggest?

* You could change the routine ONE variable at a time and see if anything changed. alter pump speed, run times, stenner settings, etc. and see if ANYTHING causes a displacement of the problem from daylight to nighttime.

* Do you have a GPM flow-rate meter in your plumbing system that you can monitor? If so any way to compare this year's readings to last year's?

*Is there a way you can test for CL concentration in a sample of water right at the return which should be just downstream from the stenner and compare that to a sample taken at the skimmer?

*Can you isolate any sections of the plumbing during the day (waterfall, spa, etc.) and see if pattern of problem changes.

*What about aussieta's idea to leave pump off during the day when you are home? I know it is scary for us to shut off filtering and chlorination in the sunlight but you could add liquid chlorine and mix it up then shut down pump and see how fast the water in the pool eats all that chlorine and in so doing you would "sort-of" isolate the plumbing system from the pool

OK, just brainstorming here trying to come up with something that might point in the direction of why so much CL consumed during day....that is some explanation other than just the sun.

 

[SunnyOptimism]

Unexplained FC Consumption (updated title)

Could I also add another variable here - doesn't heat and sun exposure ruin chlorine bleach?

What I'm getting at is maybe you're putting plenty of bleach into the Stenner pump. Perhaps the bleach is degrading while sitting outside all day. Maybe you have it all enclose and so my idea is wrong....

Is your Stenner running correctly? Are you getting the flow rates you expect?

You may have already posted this but the thread is getting really long, any metals in your water that could cause FC loss?


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[toofast]

Re: Unexplained FC Consumption (updated title)

Could I also add another variable here - doesn't heat and sun exposure ruin chlorine bleach?

What I'm getting at is maybe you're putting plenty of bleach into the Stenner pump. Perhaps the bleach is degrading while sitting outside all day. Maybe you have it all enclose and so my idea is wrong....

Is your Stenner running correctly? Are you getting the flow rates you expect?

You may have already posted this but the thread is getting really long, any metals in your water that could cause FC loss?


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Yeah I know, thread is crazy long.....

Stenner is pumping fine, bleach at 5.25% should last a few weeks as well, in protected UV container...plus when I dose the FC is right were it should be at first, then drops of course.

I tested the pumping 3 ways to Sunday and all was well...plus this is the SAME setup I had last year.

 

[y_not]

Re: Unexplained FC Consumption (updated title)

Been following your thread, I'm rather intrigued... to say the least.

A couple of ideas. Raise it to SHOCK level, then place all of your pool toys, your cover, swimsuits, net, vacuum, robot(s), hoses, pole, children.. j/k Anything that comes in contact with the pool, into the shock level water.
Let it sit for a while so the bleach can do its thing.

Also, have you verified the percentage bleach concentration with the 10k to 1 dilution?
I believe this was already mentioned, but don't recall the answer.

How about a bucket test of your pool water?
Also, where abouts do you live, what's the daily sun exposure right now of your pool, and the peak daytime air temps? How low are the night time temps? What does the water temp swing down to at night?

Is the excessive daytime FC loss WITH the cover on?

Lastly, you mentioned you have a heater? Have you checked it for algae, or bypassed it somehow to remove it as a possible infectious culprit?

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[PAGirl]

Re: Unexplained FC Consumption (updated title)

May have been stated or asked, but what was the strength of the bleach you were using last year?

 

[SunnyOptimism]

Unexplained FC Consumption (updated title)

Aside from dead squirrel sucked into one of your lines and slowly decomposing, I'm totally at a loss here.

There has to be something in the water causing that much chlorine loss. Does your water have a funky odor to it? Are you absolutely positive you have the right CYA value?

Otherwise, your neighbor is jumping the fence while you're gone and switching your bleach with tap water. Get a webcam setup and Skype that bad-boy pool of yours 24/7 while you're away.

May the pool gods have mercy on your soul (and wallet).....


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[toofast]

Re: Unexplained FC Consumption (updated title)

May have been stated or asked, but what was the strength of the bleach you were using last year?

Exact same bleach, same brand, etc...5.25%

I use that to limit the rate at which it decays, plus at .22 per oz of FC it is a great deal.

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Aside from dead squirrel sucked into one of your lines and slowly decomposing, I'm totally at a loss here.

There has to be something in the water causing that much chlorine loss. Does your water have a funky odor to it? Are you absolutely positive you have the right CYA value?

Otherwise, your neighbor is jumping the fence while you're gone and switching your bleach with tap water. Get a webcam setup and Skype that bad-boy pool of yours 24/7 while you're away.

May the pool gods have mercy on your soul (and wallet).....


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So I am at a loss as well, except you said one thing that has me thinking....

I know (because I log religiously) that I put enough CYA in to close to 60 CYA, yes it was 40 and now it is 30.

I wonder if I test again will it be 20 ? If so, that means that after I pass the OCLT my levels are not in sync with my auto lowering CYA and perhaps that is my issue. Now, why is my CYA magically disappearing...don't know, but it has to be the reason.

I will comment on some of the other ideas....

 

[aussieta]

Re: Unexplained FC Consumption (updated title)

also had another thought try leaving the cover off for a few days in case it does have something growing in the pores of the ,material
previously i mentioned are you having to drain with the quantity of bleach you are adding i would think you should have overflowed by now
if you have a lot of splashout that could account for the disappearing CYA

 

[SunnyOptimism]

Unexplained FC Consumption (updated title)

Ok. So your CYA is disappearing too? Splash out can't account for that much loss.

I'm going to go out on an anti-DIY limb here and say that I think you need a plumber who specializes in leak detection to come out and scope your pipes. Is that super expensive, yes. But both heavy CYA loss and constant FC consumption tells me you've got a funky problem there.

You do live in OH and the pool is new so it's not unreasonable that a cold winter could have caused a crack in your PVC or a fitting to come loose. It may be a small enough leak that your auto fill is compensating for it.

As Sherlock Holmes would say, "when you've eliminated all of the possibilities, the one that remains, even if highly improbable, must be the answer."

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