The only explanation for increased FC loss overnight is additional biological load in the pool consuming the chlorine.
Maybe the CYA level wasn't 0 to start with?
Maybe the CYA level wasn't 0 to start with?
Spring is coming, switching from Baquacil to Salt. What do?
- Thread starter baq2salt
- Start date
I don't think it's possible the CYA level wasn't 0 to begin with. I mean...what could have raised it? We've never had chlorine in the pool. Always been baquacil.
This morning we wake up, and the chlorine went from 19ppm last night, to 11ppm this morning. The pool is crystal clear. The filter is squeaky clean, and the media is brand new. How we were only losing 1ppm over night one week ago, and now since we changed the filter media and added CYA, we are losing MORE chlorine ppm over night EACH night. Yesterday we lost 5ppm yesterday over night, and 8ppm last night.
Again, there is no ladder in the pool, nothing was added etc. No leaves, nothing. Really need some help here guys.
This morning we wake up, and the chlorine went from 19ppm last night, to 11ppm this morning. The pool is crystal clear. The filter is squeaky clean, and the media is brand new. How we were only losing 1ppm over night one week ago, and now since we changed the filter media and added CYA, we are losing MORE chlorine ppm over night EACH night. Yesterday we lost 5ppm yesterday over night, and 8ppm last night.
Again, there is no ladder in the pool, nothing was added etc. No leaves, nothing. Really need some help here guys.
Retest your CYA, maybe bacteria are converting the CYA to ammonia.
Here are all possible options that I can think of on why the CYA result is unexpected.
CYA wasn't 0 to start
You added more than you think you did
Testing error
Your neighbor snuck over and added some extra CYA
The pool is smaller than the number you used in PoolMath
Typo in PoolMath when you did the calculation
CYA was added by using Dichlor or trichlor that wasn't accounted for
As for higher than expected FC loss. Only two things consume chlorine in a pool, sunshine and biological load.
Possible biological loads are
Algae
Bacteria
Various pool store chemicals like sequestrants, algaecides, etc
Bird or varmint urine or feces
The answer to solve any of the above is always more chlorine until the chlorine does not drop overnight.
Here are all possible options that I can think of on why the CYA result is unexpected.
CYA wasn't 0 to start
You added more than you think you did
Testing error
Your neighbor snuck over and added some extra CYA
The pool is smaller than the number you used in PoolMath
Typo in PoolMath when you did the calculation
CYA was added by using Dichlor or trichlor that wasn't accounted for
As for higher than expected FC loss. Only two things consume chlorine in a pool, sunshine and biological load.
Possible biological loads are
Algae
Bacteria
Various pool store chemicals like sequestrants, algaecides, etc
Bird or varmint urine or feces
The answer to solve any of the above is always more chlorine until the chlorine does not drop overnight.
So I have a question. The pump was off, all day. I tested the chlorine at 7pm. We're at 14ppm. Added 1 cup which Pool Math says it should take it to 15ppm.
I turned the pump on when I added that one cup. Tested again now at 10:30pm just to see how close I got it to 15ppm. It's 12.5ppm. HOW?
There is no sun, the pool sat our ALL day without more chlorine, and didn't drop much at all. Am I not supposed to test the water while the pump has been running???
There's absolutely NO WAY I lost 2.5ppm in under 3 hours in the DARK.
I turned the pump on when I added that one cup. Tested again now at 10:30pm just to see how close I got it to 15ppm. It's 12.5ppm. HOW?
There is no sun, the pool sat our ALL day without more chlorine, and didn't drop much at all. Am I not supposed to test the water while the pump has been running???
There's absolutely NO WAY I lost 2.5ppm in under 3 hours in the DARK.
What do you think the answer is? We do recommend running the pump for 15-30 minutes before testing to make sure the water is mixed and there aren't localized areas of higher or lower chlorine. Or there could have been a testing error one of those times. If you are SLAMing the pool we recommend running the pump 24x7.
Flying Tivo
TFP Guide
- Jan 24, 2017
- 2,964
- Pool Size
- 7500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
You probably had some CYA to start with, you said you imagined you had 0, that is why we TEST! No assuming from now on. Dont be chasing 2-4ppm differences. Keep your levels up and keep going.
Felipe
Felipe
Well...if there was a testing error, I've been doing it the same way since I started, so at the very least...the numbers should be consistent.
I went to bed last night without adding more chlorine. It was 12ppm with the pump running. It had been running for 3 hours since the last addition. So...it should have gone, UP.
I wake up this morning and test, the pump has been running all night, and without adding ANYTHING last night, the PPM was up to 13.5! So...either my pool is the devil itself, or I'm a giant goof.
I went to bed last night without adding more chlorine. It was 12ppm with the pump running. It had been running for 3 hours since the last addition. So...it should have gone, UP.
I wake up this morning and test, the pump has been running all night, and without adding ANYTHING last night, the PPM was up to 13.5! So...either my pool is the devil itself, or I'm a giant goof.
When I first started testing I got similar inconsistent results because I was holding the bottle on its side as I squeezed out the drops.
Once I followed the instructions
"Hold the dropper bottles vertically and squeeze gently, so that drops come out slowly and seem to hang on the tip of the dropper bottle for a moment before falling."
I started getting much more consistent results.
Once I followed the instructions
"Hold the dropper bottles vertically and squeeze gently, so that drops come out slowly and seem to hang on the tip of the dropper bottle for a moment before falling."
I started getting much more consistent results.
- May 23, 2015
- 24,464
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
We are all very glad to hear that your conversion was successful and we all wish you some very happy swimming ahead. Please continue to post questions as the need arises and we'll be here to help.
May I take a moment of your time to make a personal request? Do you see the big "Support TFP" button at the top of the page? Would you click on that and consider becoming a TFP Supporter? There is no obligation to do so and you are welcome on this forum any time no matter what you choose. We will be here to help.
Trouble Free Pools was started by a small group of folks who wanted to make a difference in the lives of residential pool owners. Since it's earliest days, TFP has remained a site on the web that is free of ad traffic and does not engage in any product endorsements for profit. This site is a 501(c)(3) non-profit organization where 100% of the site's operations are paid for by supporter donations. We do not earn money any other way. All of the Mods, Guides, Experts and Admin are volunteers and none of us are paid in any way by TFP. If TFP has brought to you the same value that it has brought to tens of thousands of pool owners, would you please consider supporting this site?
There are some perks to becoming a supporter - you get a shiny badge by your avatar name, you get larger file space for PM's and attachments, you get access to some VIP sub-forums and you'll get some coupons and discounts. But most of all, your donation as a supporter will ensure that this site remains free for all pool owners looking to take control of their pools....think of it like paying it forward....
Thanks!!