FC drops 1PPM per day. Is this normal?

[sbalberti]

I'm a little over a month in on my new 27000 gal pool. My TF100 results are as follows

FC 3
TA 90
CH 350
CC < 0.5
PH 7.5
CSI .02
CYA 50
water temp 87-94, 89 at the time of testing.


I add 32oz of 10% Chlorine every evening and 24oz of muriatic acid every other evening to keep my PH at 7.5 and FC at 4. These are the only chemicals I've put in my pool since start up.

My question is, is it normal to lose 1 PPM of chlorine per day?

 

[lmisko]

Is your pool uncovered all day? The sun alone will break down your chlorine all by itself. So even if no organic matter gets into the pool the chlorine is always on the decline.

 

[Jimrahbe]

s,

Most pools use 2 to 4 ppm a day... So, from that point of view, you are doing great...

What you are not doing so great at is keeping your FC up... With a CYA of 50 your absolute minimum is 4 ppm and your target should be 6 to 8 ppm of FC.. See this chart... [FC/CYA][/FC/CYA]

pH is good anywhere between 7.2 and 7.8... I would not add acid unless it goes outside that range... You can, but it just means you have to do it more often...

I wish my pool only used 1 ppm of FC per day...

Thanks for posting,

Jim R.

 

[sbalberti]

Yes its full sun all day with no trees to shade
_SKA4591 by Beccah-shawn Alberti, on Flickr

 

[sbalberti]

s,

Most pools use 2 to 4 ppm a day... So, from that point of view, you are doing great...

What you are not doing so great at is keeping your FC up... With a CYA of 50 your absolute minimum is 4 ppm and your target should be 6 to 8 ppm of FC.. See this chart... [FC/CYA][/FC/CYA]

pH is good anywhere between 7.2 and 7.8... I would not add acid unless it goes outside that range... You can, but it just means you have to do it more often...

I wish my pool only used 1 ppm of FC per day...

Thanks for posting,

Jim R.

I was following the TFP FC/CYA chart and keeping it around 6PPM, but my wife started complaining about her skin itching after swimming. Since i've been keeping it around 4-5 PPM she hasn't said anything. When my CYA was 30 I was burning about 4PPM per day. You know how the sun and heat are in Texas! Since raising my CYA to 50 I seem to be burning less chlorine. I haven't shocked or added any Algae preventatives that the pool store keeps trying to sell. Water still crystal clear with no signs of algae anywhere.

 

[Jimrahbe]

s,

Yes, that is exactly what CYA will do for you...

When your CYA was 30 your lower limit was only 2 ppm... With a CYA of 50 your lower limit is now 4 ppm. CYA also buffers the effect on people, so that might be the reason your wife's "cure"...

The problem with that darn algae is that it is invisible when it first starts... I'm sure you have read it many times here.... "It rained and the next day my pool suddenly turned green", or "I went away over the weekend and when I came back I had a swamp." These pool owners had algae all the time, they just did not know it, until it was too late.

That is a really beautiful looking pool you have... Very nice..

Thanks for posting,

Jim R.

 

[jstblush]

Yes, very nice pool. And I wish I only used 1 ppm a day! I'm working on that now.
Sherry

 

[sbalberti]

s,

Yes, that is exactly what CYA will do for you...

When your CYA was 30 your lower limit was only 2 ppm... With a CYA of 50 your lower limit is now 4 ppm. CYA also buffers the effect on people, so that might be the reason your wife's "cure"...

The problem with that darn algae is that it is invisible when it first starts... I'm sure you have read it many times here.... "It rained and the next day my pool suddenly turned green", or "I went away over the weekend and when I came back I had a swamp." These pool owners had algae all the time, they just did not know it, until it was too late.

That is a really beautiful looking pool you have... Very nice..

Thanks for posting,

Jim R.

I bumped up to 7 PPM today, we'll see if the Mrs. notices.

 

[Jimrahbe]

I bumped up to 7 PPM today, we'll see if the Mrs. notices.

If she does... tell her I live in California....

Jim R.

 

[borjis]

And if you have a bunch of guests over it will really eat up the the FC too.

I test and dose a little extra before guests arrive and do it again after they leave.

Swimming yesterday with 3 adults, 1 kid and full sun exposure for 5 hours ate up 4ppm.

I use a bubble cover during the weekdays though and that helps maintain somewhat better.

 

[sbalberti]

I did a OCLT and it dropped 1 PPM. Is that something to worry about?

 

[mknauss]

It could show you have some organics in the water consuming your FC. Watch for silty stuff on the floor of the pool, cloudy water, etc. Might try another OCLT in a few days.

Take care.