Pool Chemistry

Jump to latest Follow Reply
FLOMOPOOL said:
Oh boy, math. So are you telling me to add 1 gallon every 3 days, or add 1/3 of a gallon, let's see, that's 128/3 = 42 ozs every day ?
Click to expand...
All things being equal, it sounds like your pool loses about 3ppm a day. That's pretty typical, maybe a little on the light side for North Texas - a lot depends on how much sun it gets during the day, temperature, cover, usage and so on. But lets assume it's 3ppm a day.

You want to keep your FC number in the range for your CYA - 50CYA = 6-8PPM FC (with a minimum of 4).
If you dosed at sunrise up to 8ppm, and you lose 3ppm during the day, by the next morning, you'd expect to be at 5PPM. That's fine, but a little below the recommended range, and skirting with the minimum (Swampville as a certain member likes to call it). Add another dose back up to 8, lose 3, back to 5 and so on.

You suddenly get a big rainstorm, the extra water dilutes the pool a bit, and your FC is now 3 or 4ppm, and things start going green...
Sun is particularly sparkly today, you lose 4ppm not 3...now you're at 4ppm, dose to 7 forget to test, another sparkly day and you're at 3ppm...things start going green...
Running at the bottom/minimum has risks :)

Better then to dose at sunrise to say, 10 or 11ppm, knowing that you are going to lose three during the day anyway, and be at 7 or 8 PPM the next morning - never getting below the recommended range. Trust me, no one is going to notice 10PPM vs 8PPM. If suddenly the pool loses 5ppm, well now you're at 5...still in range, no panic, just redose up to 10-11 again.

Daily dosing is much more consistent - to dose for three days, you'd need to put in 9-10PPM, which on day one would mean going from 7 to 17ppm. Thats still swimmable (lower than the SLAM level) - the key though is understanding your pools demand, and the only way to do that is regular testing to see where it is, and how it behaves.

One last thing - when testing, try to be consistent - at least starting out. Sample your water from the same location in the pool. Try to sample at the same time each day. Test the same way etc. The more variables you eliminate from the process, the more accurate and reliable the results will be, and more importantly, if you suddenly get a weird result, you can be sure that its because there is something to address, and not just because you took the water from spot B vs spot A today etc.
 
  • Like
Reactions: FLOMOPOOL, Newdude and wireform
SJPoe said:
All things being equal, it sounds like your pool loses about 3ppm a day. That's pretty typical, maybe a little on the light side for North Texas - a lot depends on how much sun it gets during the day, temperature, cover, usage and so on. But lets assume it's 3ppm a day.

You want to keep your FC number in the range for your CYA - 50CYA = 6-8PPM FC (with a minimum of 4).
If you dosed at sunrise up to 8ppm, and you lose 3ppm during the day, by the next morning, you'd expect to be at 5PPM. That's fine, but a little below the recommended range, and skirting with the minimum (Swampville as a certain member likes to call it). Add another dose back up to 8, lose 3, back to 5 and so on.

You suddenly get a big rainstorm, the extra water dilutes the pool a bit, and your FC is now 3 or 4ppm, and things start going green...
Sun is particularly sparkly today, you lose 4ppm not 3...now you're at 4ppm, dose to 7 forget to test, another sparkly day and you're at 3ppm...things start going green...
Running at the bottom/minimum has risks :)

Better then to dose at sunrise to say, 10 or 11ppm, knowing that you are going to lose three during the day anyway, and be at 7 or 8 PPM the next morning - never getting below the recommended range. Trust me, no one is going to notice 10PPM vs 8PPM. If suddenly the pool loses 5ppm, well now you're at 5...still in range, no panic, just redose up to 10-11 again.

Daily dosing is much more consistent - to dose for three days, you'd need to put in 9-10PPM, which on day one would mean going from 7 to 17ppm. Thats still swimmable (lower than the SLAM level) - the key though is understanding your pools demand, and the only way to do that is regular testing to see where it is, and how it behaves.

One last thing - when testing, try to be consistent - at least starting out. Sample your water from the same location in the pool. Try to sample at the same time each day. Test the same way etc. The more variables you eliminate from the process, the more accurate and reliable the results will be, and more importantly, if you suddenly get a weird result, you can be sure that its because there is something to address, and not just because you took the water from spot B vs spot A today etc.
Click to expand...
THANK YOU so much for your help. I am going to go higher like you suggest to 10-11 and keep it there at least to the end of October when the heat subsides around here. That's when I also cut back to pump running only 8 hours a day.

I just checked and I am still at 5 ppm = no change overnight.

I just added a whole gallon of 10% bleach and will re-test in 2 hours (?) to give it a chance to fully circulate, to see where the added gallon has taken me so I know how amounts affect my pool. Will let you all know in a couple of hours on that. According to Pool Math it the added gallon should take me to 15.

1722612588691.png
 
FLOMOPOOL said:
THANK YOU so much for your help. I am going to go higher like you suggest to 10-11 and keep it there at least to the end of October when the heat subsides around here. That's when I also cut back to pump running only 8 hours a day.

I just checked and I am still at 5 ppm = no change overnight.

I just added a whole gallon of 10% bleach and will re-test in 2 hours (?) to give it a chance to fully circulate, to see where the added gallon has taken me so I know how amounts affect my pool. Will let you all know in a couple of hours on that. According to Pool Math it the added gallon should take me to 15.

View attachment 601488
Click to expand...
Yep, just checked and FC went up to 15 ppm after adding entire gallon of 10% bleach 1.5 hours ago.

So assuming it will lose 3 ppm over today, it should be at 12 ppm tonight (I will check at 8 pm) and in the morning. If that's true, I will not add any chlorine tomorrow (Saturday) morning and it should drop to 9 ppm Saturday night. If that is true, I will add enough on Sunday morning to bring FC up to 12 ppm, so, 42 ozs, and then it should drop back down to 9 ppm over Sunday. And same there on out. I will keep testing and posting results along the way.

I am going to brush the pool this afternoon so I wonder if that will have an affect on current FC level. Will test tonight to check.
 
SJPoe said:
Just remember, if its sunnier tomorrow than today, it might be 4...not 3...or vice versa...
Click to expand...
Yes Sir. I do have sun sails on my pool so hopefully that helps some. I will still do testing each evening and morning, regardless of whether I add bleach or not. I am going to do a full hand brushing now and also a full filter cleaning in the morning just so everything is on the up and up.
 
  • Like
Reactions: Newdude
Just did tonight's test. FC started at 15 ppm this morning, because I added an entire 1 gal. of bleach, and now it's at 9 ppm. The loss due to sun is about 3 ppm Would the other 3 ppm be due to my thoroughly brushing the pool this afternoon ? Am I right that the chlorine is used up not only by the sun but also eating up any green algae stirred up as a result of brushing ?
 
That is a large loss. Are you seeing algae?

What is your CYA?

How long did you wait to test FC after adding chlorine? Did you test before adding? What was it?
 
PoolStored said:
That is a large loss. Are you seeing algae?

What is your CYA?

How long did you wait to test FC after adding chlorine? Did you test before adding? What was it?
Click to expand...
There was a little green algae when I brushed the pool this afternoon.

CYA is about 50.

I tested this morning first thing BEFORE adding bleach, it was 5 ppm, which was same as last night's test, so no lose overnight.

Then this morning, after test showing 5 ppm, I added 1 gal. of bleach, let it circulate for a couple of hours and then tested again = 15 ppm.
 
Cleaning filter now - what do you think:

1. Is the green the algae that I brushed off yesterday afternoon (pump ran for a good 4 hours after brushing (and 1/2 hour this morning before I shut it down and took it apart) ?

2. Does amount of DE look good ? I have a 48 sq. ft. filter so I need 4.8 pds. = 77 ozs = 6 1/2 scoops @ 12 oz/scoop (I used my kitchen scale to get actual DE weight in scoop). Should I use exactly 4.8 or round up to I put 7 scoops ?

1722695849647.png
 

Enjoying this content?

Support TFP with a donation.

Give Support
Ok, filter fully cleaned and fresh DE. It rained early this morning so my PH is a little high to SLAM, it's 7.8 so I just hit it with muriatic acid to bring it down to between 7.2 - 7.5 per SLAM instructions.

My CYA = 45-50, so my SLAM FC is 20. Current FC = 8; CC = 0. Will pick up 6 more gallon jugs of 10% bleach now.

How long do I wait for PH to come down so I can begin SLAM ?

Thanks so much.
 
Ok, my PH is down to 7.4-7.5 and my FC is at 6, will now SLAM to 20.

Based on Pool Math, I just added 1.5 gals. of 10% bleach - will check FC in 3 hours to get loss, and bring it back up to 20.

Will do the same at 9 pm., let the filter run overnight, and then note any overnight loss in the morning, and SLAM tomorrow morning, afternoon and evening..

Do I have it right ?
 
Ok, now at 6 pm, so 3 hours later from first SLAM dose, FC is down a bit to 18 (CC = 0). I went ahead and added the remaining 1/2 gal. (or so). Will test again at 9 pm and then next in the morning, which will show if any overnight loss.

Am I on track here ? Thanks.
 

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