FC level

[lucyyan]

Recently I had an issue with CYA Being too high. We were using stabilized pucks with cal. Hypo to chlorinate our pool. We were never told by the pool company to drain the pool till it was way too high and our pool was cloudy. Long story short we drained the pool and now CYA is 50. But according to the calculator we need FC to be at 6ppm? Is that way too high to swim in? I read on some sites recommended safe level is 3ppm or 4.

 

[rcs29]

SLAM level for CYA of 50 is 20 ppm FC I believe. You are safe to swim in water up to SLAM level. The 3-4 thing is not something you'll see recommended at TFP because TFP doesn't want you to swim in unsanitary water or have algae blooms. What are you using to achieve testing resluts?

 

[Texas Splash]

I read on some sites recommended safe level is 3ppm or 4.

That is very generic pool store/industry ranges with no regard to the FC/CYA relationship. Basically, there are ideal ratios for both normal FC sanitation and elevated levels to kill algae. You can see those levels below and on our FC/CYA Levels.

Notice what each chart is designed for. It's the same as the link above. If you have algae, you'll want to follow our SLAM Process.

Be sure to visit our Pool Care Basics page, and always test your water with either a TF-100 or Taylor K-2006C test kit.

Update your signature with all of your pool and equipment info, and let us know if you have any questions.

 

[Texas Splash]

Oh, and of course ...... Welcome to TFP!

 

[lucyyan]

I've been testing water at the pool place. I am slowly realizing they don't know what they are doing. One girl told me stabilized pucks doesn't increase cya cuz the amount is so little. And when our cya was over 100 she said to only drain 6 inches below the skimmer box. So I plan on getting a test kit. We cant get the TF pro in Canada but I am ordering Taylor k 2006 c kit! Im going to switch to liquid chlorine as well. I don't know how much to put in each day till my test kit comes in. So I may still have to get my water tested there and just add a weekly dose of liquid chlorine?

 

[Texas Splash]

I don't know how much to put in each day till my test kit comes in.

Be sure to download the PoolMath APP. It has a nice feature called "Effects of Adding". So once you load all of your pool info into the APP profile, that section can help tell you what changes to expect by adding x-amount of any product. In your case, I would just add 4-5 ppm of liquid chlorine each day until the kit arrives. In the APP, look for Bleach and select the proper % strength. Hope that helps.

 

[mgtfp]

But according to the calculator we need FC to be at 6ppm? Is that way too high to swim in? I read on some sites recommended safe level is 3ppm or 4.

Welcome to TFP!

There is some background information on the reasons behind TFP's recommended FC levels in this article:

CYA Chlorine Relationship - Further Reading

www.troublefreepool.com

In a nutshell, same ratios of FC/CYA yield the same amount of HOCl, which is what keeps a pool sanitised. You want enough of that, but also not too much. But you have to go way high before it's too much, but not that far down to have not enough. That's what above posted charts are all about. And anything up to SLAM -FC for the respective CYA level is safe to swim in.

 

[lucyyan]

Be sure to download the PoolMath APP. It has a nice feature called "Effects of Adding". So once you load all of your pool info into the APP profile, that section can help tell you what changes to expect by adding x-amount of any product. In your case, I would just add 4-5 ppm of liquid chlorine each day until the kit arrives. In the APP, look for Bleach and select the proper % strength. Hope that helps.

so 4-5 ppm would be around 3.5 to 4ish Litre of 10.5% chlorine. Is chlorine depleted by that much each day??
On Monday I had the water tested at a pool place (I am unable to get a test kit at this moment):

FC 1
TA 110
PH7.4
calcium 310
combine Cl 0
CYA 50

That night i added 3.5L of 10.5% chlorine

the next evening the chlorine was probably back to 1 or maybe btw1-2 (I tested with a test strip so it might not be totally accurate but ball park its around that )

Is that normal for chlorine to be that depleted by the end of the day? It was very humid and hot that day.

 

[Texas Splash]

Is chlorine depleted by that much each day?

On a normal day with even little to no swimming, a pool can lose between 2-4 ppm of FC each day just from the sun's UV. With a lot of swimmers slightly more. If you have algae, then the FC drops exponentially faster.

 

[lucyyan]

On a normal day with even little to no swimming, a pool can lose between 2-4 ppm of FC each day just from the sun's UV. With a lot of swimmers slightly more. If you have algae, then the FC drops exponentially faster.

where and how are you purchasing your liquid chlorine? In jugs or like a big container full. Seems like so much jugs of chlorine to purchase each week or month if you buy all together. I feel bad using so many chlorine jugs. Usually we buy the chlorine from Canadian tire its like an automotive, home hareware and sporting store.

 

[mgtfp]

Have you considered a Salt Water Chlorine Generator? Upfront investment, but long-term way cheaper. And so much more convenient.

 

[Texas Splash]

where and how are you purchasing your liquid chlorine? In jugs or like a big container full. Seems like so much jugs of chlorine to purchase each week or month if you buy all together. I feel bad using so many chlorine jugs. Usually we buy the chlorine from Canadian tire its like an automotive, home hareware and sporting store.

Yes, that's something every pool owner is challenged with locally. Your best bet is as suggsted above to get a Salt Water Generator at some point. It's an up-front cost, but then you don't have to worry about jugs all the time.

 

[lucyyan]

typically i find i would need to add 3.5 L per day! i feel like its terrible for using so many jugs. Thanks for all the helpful advice. Pool chemistry is pretty interesting. So much to know.

 

[lucyyan]

Have you considered a Salt Water Chlorine Generator? Upfront investment, but long-term way cheaper. And so much more convenient.

its funny our pool was a "salt water pool" we had a salt generator but the pool company told us salt water pool are more corrosive to the pool equipement. So we changed it to a chlorine pool. Is there any truth to that. Now I feel they said that because its more costly for chemicals.

 

[mknauss]

A salt pool is a chlorine pool, and a chlorine pool is a salt pool.
A salt pool is no more 'corrosive' than a pool using liquid chlorine.
Realize that pool water pH is by far the most important factor regarding 'corrosive'. A low pH, below the 7's, is damaging to your pool liner.

 

[wireform]

its funny our pool was a "salt water pool" we had a salt generator but the pool company told us salt water pool are more corrosive to the pool equipement. So we changed it to a chlorine pool. Is there any truth to that. Now I feel they said that because its more costly for chemicals.

Thats what they said because it's better for their bottom line and probably they know next to nothing about the quote on quote "salt pool" thing. Accordingly everyone of us here should have major corrosion problems but we don't.

 

[DavidArmenB]

Is that normal for chlorine to be that depleted by the end of the day? It was very humid and hot that day.

My pool, which is completely algae free and rarely ever hosts any swimmers, is losing about 3.5ppm of FC every single day in this 100 degree heat. If I used pure 10% bleach, I’d need to add 2.2 liters per day. But no liquid chlorine is ever brand new, the newest ones I could find at stores were already over a month old, so at best they are at half strength by the time I would buy them, making them 5%. So I would need to use about 4.4 liters per day.
Today’s Readings
FC: 7.6ppm
OCLT 0.2ppm
CC 0.0ppm
CYA is 60ppm
Side note but I’m actually going to raise my CYA to 80ppm tomorrow.

This is obviously completely pool/SWCG/runtime dependent, but just so you see the difference, I have my SWCG bumped all the way up to 40% (3.4ppm/day) due to the intense heat of this summer, while my winter percentage was merely at 6% (0.5ppm/day).

 

[wireform]

So a month old chlorine is still perfect and if you're not getting what you think is the strength, get the chlorine elsewhere and compare but I believe you have something growing aka algae in the pool and you haven't confirmed it. This link
Overnight Chlorine Loss Test is what you need to follow before you raise the CYA and do yourself in if a slam is in order. Don't raise the CYA till all checks out. Get yourself a real test kit to do your own testing as pool store results are unreliable and then we can help you get to the bottom of the pool issues.

 

[mgtfp]

its funny our pool was a "salt water pool" we had a salt generator but the pool company told us salt water pool are more corrosive to the pool equipement. So we changed it to a chlorine pool. Is there any truth to that. Now I feel they said that because its more costly for chemicals.

Hmmm, that was unfortunate. I guess trouble free customers don't fit into their business model.

Honestly, I wouldn't want my pool any other way. Either a salt pool, or no pool.

 

[lucyyan]

So a month old chlorine is still perfect and if you're not getting what you think is the strength, get the chlorine elsewhere and compare but I believe you have something growing aka algae in the pool and you haven't confirmed it. This link
Overnight Chlorine Loss Test is what you need to follow before you raise the CYA and do yourself in if a slam is in order. Don't raise the CYA till all checks out. Get yourself a real test kit to do your own testing as pool store results are unreliable and then we can help you get to the bottom of the pool issues.

i think maybe i am losing a lot of chlorine due to algae. I can see a little bit forming a the seams of the liner in the deep end. I am still waiting for my Taylor kit to arrive from amazon and I will attempt to do a SLAM.