Unexplained FC Consumption - SOLVED - although the Mystery Remains

Jump to latest Follow Reply
Re: Unexplained FC Consumption (updated title)

I have to share with you that I have to use more chlorine each night than I did last summer. As in it is lower when I test after the sun is off the pool so..............I have to add more to get it up to the proper level for the next day.

We have had quite a bit more rain this year and the humidity has been high! I wonder if this had anything to do with it???

Kim
 
Re: Unexplained FC Consumption (updated title)

Well I am home for 2 days and started a SLAM hoping to pass OCLT for then next 2 nights.

Came home to

FC = 8.5
CC = 0 and pool looking like this...this is about 4 ft of water.



This is the deep end about 6.5'



Increased FC and at 9 PM I have

FC = 15
CC = 0
CYA = 30

Will test at Midnight before sleep and increase dose and then test again in morning. I am working for home all Monday, not leaving till 4 AM on Tuesday....so wish me luck.

I still used quite a bit of FC over the last 5 days...nearly 2.5 gals a day - however my FC was "higher" than normal once returning home...perhaps the next two days of real SLAMMING will finally slay the invisible beast!
 
Re: Unexplained FC Consumption (updated title)

I will def agree that I am using more daily this year then last. I use pretty much a full gal a day. I have passed numerous OCLT. Running .5 CC. I would say the only differences this year vs last is I have added a heater. And obviously we use the pool more now. I am running between a 30-40 CYA. Have you had any trees removed? Pool getting more sunlight? If not bather load?
 
Re: Unexplained FC Consumption (updated title)

mrmacdad12 said:
I will def agree that I am using more daily this year then last. I use pretty much a full gal a day. I have passed numerous OCLT. Running .5 CC. I would say the only differences this year vs last is I have added a heater. And obviously we use the pool more now. I am running between a 30-40 CYA. Have you had any trees removed? Pool getting more sunlight? If not bather load?
Click to expand...

This is a "new pool" and nothing has changed since last year....other than the love for chlorine. No trees and lots of sun.

Last year I was burning about 2 PPM per day - other than when I would have 15 people in the pool for hour and then it drank a bit more of course.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Re: Unexplained FC Consumption (updated title)

i had a light bulb moment today
when you are at slam level you pass oclt but not at normal levels
there must be a source of algae or bacteria entering pool from a source not exposed to your chlorinated water
ie a breeding ground somewhere
at slam levels it is killed as it enters pool but at normal levels it puts up a fight and consumes excessive chlorine
now to figure out what it could be
heat pump? wildlife? auto fill? any other places that have little or no chlorinated water flow but allow access to pool
 
Re: Unexplained FC Consumption (updated title)

Butterfly said:
What are those white round things (pop-ups? lights?) in the pool? Sorry, old eyes.
Click to expand...

The things on the bottom are the main drains and the thing up top is the LED light.

- - - Updated - - -

aussieta said:
i had a light bulb moment today
when you are at slam level you pass oclt but not at normal levels
there must be a source of algae or bacteria entering pool from a source not exposed to your chlorinated water
ie a breeding ground somewhere
at slam levels it is killed as it enters pool but at normal levels it puts up a fight and consumes excessive chlorine
now to figure out what it could be
heat pump? wildlife? auto fill? any other places that have little or no chlorinated water flow but allow access to pool
Click to expand...

Yes - something wacked is going on.

I actually plugged my auto fill just to take that 100% out of the equation.
I mean I have a bit of dirt around the pool, still finishing up landscaping, and when the wind blows hard the pool gets a bit of dirt in it.

I also have a Heat Pump - but the water flows through that continuously (or so I am told).

I have a fence so no wildlife, other than the occasional tree frog once in a while.

Also, I mentioned I have a solar cover, and although there is no green underneath anywhere, I do get a bit of "dirt" built up top like I am sure everyone does.

Like you I am baffled...

- - - Updated - - -

OCLT Results:

9 PM

FC - 15
CC - 0

7 AM

FC = 14.5
CC = .5

Water is crystal clear....

I am home again today, so I will maintain SLAM levels all day again and through the night just to see if a second day helps. But this is feeling very familiar....passing tests but then still having issues.

Like aussieta mentioned above, something MUST be entering the pool and causing this continuous problem...but what the heck is it.
 
Re: Unexplained FC Consumption (updated title)

Well another day and another bummer....

It is 8:30 PM and my test is this

FC = 12.5
CC = .5

With what I dosed today, I consumed nearly 8 PPM today of FC.

I leave for a plane ride tomorrow at 4 AM back on Friday Night....looks like my only option is to drain the pool and start over. I will test at 3 AM today just for fun to see what happens overnight....but I bet I will pass the OCLT yet again.
 
Re: Unexplained FC Consumption (updated title)

The higher your chlorine number is, the more you will lose during the day in the sunlight. That is why you are probably losing so much. You may not be fighting anything at all, you are just losing all of that extra chlorine to sunlight. If you have passed the OCLT test, then trust that you are good and let the chlorine fall to it's normal number. If your cya is let's say, 40, target for 7 that evening. Dose to 7 if you need to. Don't check it again until the next evening. If your FC is still in the 3-5 range, you are fine. If you keep you chlorine right where it is supposed to be, a normal burnoff during the day is anywhere from 2-4 ppm's. If you keep adding more during the day, the sun is just going to burn that extra off. Does this make sense?

Sorry, just went back and re-read everything. Didn't realize you were injecting with a stenner (which I know nothing about).
 
Re: Unexplained FC Consumption (updated title)

aussieta said:
i wouldn't drain the water as i don't believe that is your problem
have you used a lot of fertilizer in the garden?
Click to expand...

Now that I have a few minutes (love wifi on planes) I will update.

I do not have a garden - and although my grass does get fertilized, the grass is all sloped away from the pool and at least 10 ft away on all sides.

I really don't want to drain and I think I was just venting to myself to mention that, but I am really at a lose. I will let levels go back to normal, increase my CYA to 40 and see what happens.

I really only have one idea left...so here it goes.

When I travel, the pool is left covered and not used for days on end (3-4 at a time). I always run my pump on low while gone. Is it possible that somehow I have poor circulation (even though I have three intakes and three returns) with the low setting on pump and "chlorine" is not really getting to the deep corners and a bit of algae starts to grown, but then dies once things get stirred up a bit. I always seem to have light brown "dust" on the bottom and sides and figured that was just dirt. But could it be some kind of algae forming and then dying out quickly, but in the meantime eating my FC ? (But why during the day at night?)

Any other tests, etc that I can do please let me know.

- - - Updated - - -

pepsiholic said:
The higher your chlorine number is, the more you will lose during the day in the sunlight. That is why you are probably losing so much. You may not be fighting anything at all, you are just losing all of that extra chlorine to sunlight. If you have passed the OCLT test, then trust that you are good and let the chlorine fall to it's normal number. If your cya is let's say, 40, target for 7 that evening. Dose to 7 if you need to. Don't check it again until the next evening. If your FC is still in the 3-5 range, you are fine. If you keep you chlorine right where it is supposed to be, a normal burnoff during the day is anywhere from 2-4 ppm's. If you keep adding more during the day, the sun is just going to burn that extra off. Does this make sense?

Sorry, just went back and re-read everything. Didn't realize you were injecting with a stenner (which I know nothing about).
Click to expand...

I totally agree with your post, in fact that is what I expected to happen and thus why this thread was started. I burn a TON of FC during the day no matter at what levels...and can't figure out what, oh - and my pool is clear as in the pics above.

Stenner is just using a pump to automate the pouring of the bleach...so it doses XX amount through out the day, depending on how I have the timers set.
 
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
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply