Clearing algae

[proavia]

Re: main drain has dirt and debri sitting in the bottom-no suction?

Yes chlorine at high levels is absolutely toxic. I do not get in the pool or allow my kids to swim if chlorine is over 5ppm. I would finish the slam and let chlorine levels come down before swimming.

Josh - with your SWCG, what is your CYA? And what FC levels do you maintain?

Care to provide links - which include taking the CYA/chlorine relationship into account?

Sure, many of us have seen the various papers that recommend chlorine levels of 1.0 to 3.0 ppm that fall within most health department guidelines. But most (if not all) of those don't take the CYA/chlorine relationship into account.

If the above 1.0-3.0 is to be believed, a SWCG pool with the minimum TFP recommendation of 70 CYA is going to be "over-chlorinated" the majority of the time - as the minimum is 3 and target is 5. Now, I'm not saying that you couldn't over chlorinate your pool --- but using the guidelines on the TFP site (which have factual science backing them) is perfectly safe. Also, what about the statement you've seen on the site hundreds of times about it being okay to swim if your FC is between minimum and shock levels (3-28 for CYA of 70 in a SWCG pool)? Not saying I'd swim EVERY day in FC levels nearing shock level for my CYA, but a few days during a SLAM - you bet I would.

Not trying to start an argument - or even a debate in this thread --- but making the statement you did isn't backed by the teachings of this site. I'm sure many would be willing to discuss this further - but in a new thread. More important right now to get the OP's CYA level up and dial in her SWCG to help keep her pool sanitary and healthy.

 

[outdoorsgal]

Re: main drain has dirt and debri sitting in the bottom-no suction?

I've been following along and hope this is helpful.

Kim and Proavia both gave good advice on the OCLT. The procedure says after sunset and before sunrise. Kim allowed for darkness because she knows you're a night-owl. Proavia went by the procedure as written. Either way is fine for the nighttime one.

Proavia wants the morning test before sunrise, per the procedure, again, Kim knows you're a night-owl, so was allowing that to be a little later, but it must be before the slightest sun has hit the pool. Some people like to stick to sunrise for the test, and that works the best, but both work.

Both Kim and Proavia want you to keep the SLAM going until you pass the criteria which indicate the SLAM has done the job.

needsajet, the part that I was saying Kim and Proavia were in disagreement about was the amount of chlorine needed to do a SLAM. As far as the OCLT, I tried to follow it to the T of Proavia's advice, but it seems like both make sense, that if you have a long enough time you should be able to see if algae is eating the chlorine. This is now a good tool I have in my toolbox.

- - - Updated - - -

Kim, I'm curious, since you thought the ppm didnt need to be more than 5 for a SLAM, what do u keep your pool at on a reg basis? I believe the TFP instructions you sent me said the ppm needed to be at least 3 which seems to be more of the pool industry standard. i'll be curious to learn more about CYA and the balance. thx

 

[proavia]

Re: main drain has dirt and debri sitting in the bottom-no suction?

PRoavia, I'll wait to learn more about the balance of CYA/chlorine levels. I never fully understood this and if I am raising my CYA to match a high amount of chlorine I don't want to raise my CYA anymore and want to learn more first. I have not been comfortable with and can't imagine I will ever be comfortable with a high level of chlorine. I dislike my pool now and the kids don't want to swim either. I'll look forward to an explanation of where this is going. I've decided I am sticking with lower levels of chlorine. I think the pool company said 3 and would have to go back to look at my previous kit. My son still has his headache today and my daughter was up til midnight complaining of her eyes burning not to mention what I've read about chlorine being a carcinogen. My intentions always have been and still will be to maintain a pool with the lowest level of chlorine as possible. If I need to have the CYA and chlorine balanced I will use my chlorine as a baseline and then match the CYA to that. I can imagine there may be times I need to raise the chlorine. That's what most people do, right? They shock their pools as needed? I need to read more I think but so far I'm not clear on what was wrong with the pb's method of keeping the pH and chlorine at their recommended levels. Since we never did a good job of that I never got a chance to see if it'll work. I look forward to hearing you out. Thank you.

Look at the Chlorine / CYA Chart - for SWG Pools. The minimum recommended CYA level is 70 for SWG pools. The FC minimum level is 3 and target is 5 according to that chart.

A SWCG can produce chlorine only while the pump is running. And will only provide chlorine based on the percentage it's set to. So, if pump runs 4 hours per day and the SWCG is set for 50%, the SWCG is producing chlorine for 2 hours. Can it produce enough to keep your pool properly chlorinated - only time will tell. Through experimentation, you will need to balance pump run time and SWCG production to provide the needed chlorine for your pool. It will take a bit of trial and error - but once it's dialed in, you will only need to test daily with the small blue kit and do the other tests provided weekly or so.

Having the CYA at 70 helps hold chlorine in reserve for when the SWCG isn't producing chlorine. The SWCG produces chlorine to help maintain in the minimum to target range. It's not real good in producing above that rate - especially if algae starts up due to the FC falling too low. The reason to need to sometimes supplement the SWCG with liquid chlorine/bleach is because the SWCG can't keep up. And, there may be times you need to shoot for above target by 1 or 2 (maybe more??) based on bather load, weather, etc.

That's kind of the simple way I know to explain it. There's more to it that one of our experts and/or mods can better explain if they'd like.
______________________

If you really want to keep the algae away and have a sanity, properly chlorinated pool:
Raise CYA to 70
Never let FC drop below 3
Spend the time to dial in your SWCG and pump run times to provide the FC required
Test frequently - especially at first

Thanks!

 

[outdoorsgal]

Re: main drain has dirt and debri sitting in the bottom-no suction?

checking a couple of things cuz i want my kids to be able to swim, but only if the chlorine has gone down. does CYA raise pH so we can't get an accurate reading at this point? i cheated on one thing because I have been hesitant about keeping so much chlorine in the pool and I didn't squeeze out the rest of the CYA into the skimmer last night and I haven't taken a look at it today to see if it's still in the sock. But in checking what I'd consider "the basics" on the new test kit for pH I got 7.5. on my old kit I got 7.8. For chlorine on the old kit I am reading 2.0 on my old kit (can't be right) and my new kit reads above 5 so i'll test it with the reagent that will check the FC

- - - Updated - - -

FC= 8 drops so it's already down to 4. i'm surprised it went down so quickly. looks like i'll go squeeze out the rest of the CYA now. skimmed your post, Provia. i'll be right back after turning back on my salt cell

 

[proavia]

Re: main drain has dirt and debri sitting in the bottom-no suction?

checking a couple of things cuz i want my kids to be able to swim, but only if the chlorine has gone down. does CYA raise pH so we can't get an accurate reading at this point? i cheated on one thing because I have been hesitant about keeping so much chlorine in the pool and I didn't squeeze out the rest of the CYA into the skimmer last night and I haven't taken a look at it today to see if it's still in the sock. But in checking what I'd consider "the basics" on the new test kit for pH I got 7.5. on my old kit I got 7.8. For chlorine on the old kit I am reading 2.0 on my old kit (can't be right) and my new kit reads above 5 so i'll test it with the reagent that will check the FC

Might be time to go back and review some pool school articles.

FC below 10, pH tests correctly
CYA may cause pH to move ever so slightly - but probably not enough to make a big difference
Not enough CYA will cause the sun to burn off a lot of chlorine

Are you using the tester in the small blue box that came with your TF100 to test chlorine or the FAS-DPD test (with the powder) to get an accurate FC reading? Sounds like the old kit may have been outside or the reagents have gone bad. Please use only the contents of the TF100 (FAS-DPD test) and the small blue kit that comes with it.

 

[outdoorsgal]

Re: main drain has dirt and debri sitting in the bottom-no suction?

proavia, never letting chlorine drop below 3 sounds more comfortable to me. i set my chlorinator at 100% and I will test daily to see. In the past that wasn't cutting it but I'm hoping there is a correlation with not having kept my pH at the right level as well? Makes sense that I'd need to add more CYA if it's dropped from a 9.5 to 4 by 2pm. Another option, I would imagine, would be to run the pump twice a day. I run it from 10p-10am, I think it is. It's on high for 4-4.5 hrs (I'd have to check). My preference is to not add chlorine from the bottle but I will if I have to. Heck, I have 8+ gallons of it, still. Salt generated chlorine and the stuff in the bottle seems to have a different feel to it and if I can balance the CYA and make enough chlorine from the salt cell outside of peak hours that sounds like a good deal. That'll also help clean the floor a bit more perhaps and if nothing else, keeping the water running is a good thing. In following one thread on this site I learned the cell produces at the same rate whether it's on high or low and running it on low, I was told by pb, is like turning on a lightbulb.

One statement this confused me on the chlorine/CYA chart Pool School - Chlorine / CYA Chart was where it said "Most saltwater chlorine generator (SWG) pools appear to prevent algae at a lower minimum FC level compared with the minimum FC column for manually dosed pools" but then the chart shows the minimum requirements in a salt pool are higher than chlorine since the minimum level of CYA is higher.

I have another couple pounds of CYA in the shed. would i check CYA first or are u pretty confident without testing that I'll need so much more? Why did my test measure "zero" (but "probably ten") and Leslie's measured 30. how is it that their test is thought to not be accurate and my new kit/TF-100 is?

The old kit I talk about, the one that came with the pool, was always left inside, however we let it get to 90 in the house when we're outside or not home... Do u think that temp could ruin a kit? we have single pane windows and it doesn't take much to go up a good 8 degrees during peak hours if i turn the air up or shut it off... i was wondering if it had to do with the limitations of the colors or just how it reads. when I got conflicting numbers I used the one with the reagant and the powder that came with the TF-100. is that the one I should use daily until I am dialed in or is it reasonable to start with the blue kit? the one with the powder seems more accurate. it read 4 where I got 5 out of the blue kit. that's a bit disheartening. how good is the blue kit, then? or in the end is it ok since it was still in the range? thanku and yes, good time to review articles. trying my best time-wise.!

 

[outdoorsgal]

Re: main drain has dirt and debri sitting in the bottom-no suction?

also, Kim mentioned the possibility of scaling? r we still yet to get to TA, Calcium, tips for how to keep pH at a good number like aeration...? i'll be reading, anyway. thx!

 

[proavia]

Re: main drain has dirt and debri sitting in the bottom-no suction?

My responses in Blue

proavia, never letting chlorine drop below 3 sounds more comfortable to me. i set my chlorinator at 100% and I will test daily to see. In the past that wasn't cutting it but I'm hoping there is a correlation with not having kept my pH at the right level as well? Makes sense that I'd need to add more CYA if it's dropped from a 9.5 to 4 by 2pm. Another option, I would imagine, would be to run the pump twice a day. I run it from 10p-10am, I think it is. It's on high for 4-4.5 hrs (I'd have to check). My preference is to not add chlorine from the bottle but I will if I have to. Heck, I have 8+ gallons of it, still. Salt generated chlorine and the stuff in the bottle seems to have a different feel to it and if I can balance the CYA and make enough chlorine from the salt cell outside of peak hours that sounds like a good deal. That'll also help clean the floor a bit more perhaps and if nothing else, keeping the water running is a good thing. In following one thread on this site I learned the cell produces at the same rate whether it's on high or low and running it on low, I was told by pb, is like turning on a lightbulb.

• I agree, never let it get below 3 for a CYA of 70. But you always need to target above that 3 number, cause when the pump is off the SWCG is not producing chlorine and the sun, bathers, etc. are using chlorine.
• Possible reason the SWCG wasn't keeping up is that CYA was virtually non-existent. The recommended minimum CYA level for a SWCG pool is 70.
• Running pump for two cycles daily would probably be best. Maybe one on high speed for the in-floors to work better and one on a lower speed to save electricity while still producing chlorine.
• 12 hours a day is most probably too much. I would shoot for 4-5 hours on high for the in-floor and maybe 4-5 on a lower speed for circulation and continued SWCG production. And if I recall, you are on SRP easy-3 -- so no reason to run pump on schedule during 3pm-6pm (I think that's the times).
• Slowest pump speed needs to be determined based on if SWCG will actually generate chlorine at that speed. The SWCG requires a minimum flow rate to work - and some here set the pump rpm to be 100-200 above that as flow will decrease as filter becomes more dirty.
• Yeah, if needed add liquid as needed. If you're going to have a pool party, the night before (with pump running) add a few ppm of chlorine. Check the pool when everybody is done and add a few more if needed to get to target (not minimum).
• Yes, SWCG generates based on the percent it's set for - regardless of pump speed - as long as you're above the minimum pump speed to allow it to generate (see "flow rate" response above).

One statement this confused me on the chlorine/CYA chart Pool School - Chlorine / CYA Chart was where it said "Most saltwater chlorine generator (SWG) pools appear to prevent algae at a lower minimum FC level compared with the minimum FC column for manually dosed pools" but then the chart shows the minimum requirements in a salt pool are higher than chlorine since the minimum level of CYA is higher.
For the same CYA (comparing apples to apples), in a non-SWG pool, it's recommended to keep the levels higher. This is because, for a SWG pool, the chlorine is produced slowly over a longer time period. Think of it like this - the pool is going to require "X" amount of chlorine per day (24 hours period). This is whether manually dosed with liquid chlorine or when using a SWCG. With manual dosing, you are adding the chlorine all at once (over a time span of say a minute). Hence you need to target a higher number when dosing to remain at or just above target for an entire 24 hour period. The SWCG produces chlorine a little at a time over a much longer period (during pump run time - 6, 8, or more hours) in a given 24 hour period. So you can add "X" amount all at once (MINUTES) with manual dosing or dose over a long period of time (HOURS) with a SWCG.


I have another couple pounds of CYA in the shed. would i check CYA first or are u pretty confident without testing that I'll need so much more? Why did my test measure "zero" (but "probably ten") and Leslie's measured 30. how is it that their test is thought to not be accurate and my new kit/TF-100 is?
Do a full set of tests and provide a full set of current numbers here.

4 pounds of stabilizer - according to Pool Math - is going to add 34 CYA to your 14k pool.
Based on your previous results of "about 10" and adding enough to get to 30, you are still going to be below recommended levels. I think you said you probably didn't add enough a few days ago to get to CYA of 30 (something about weight versus volume when measuring). How much is left in the container you purchased?

With your updated test results, we can determine where you are and how much additional you will need.

The old kit I talk about, the one that came with the pool, was always left inside, however we let it get to 90 in the house when we're outside or not home... Do u think that temp could ruin a kit? we have single pane windows and it doesn't take much to go up a good 8 degrees during peak hours if i turn the air up or shut it off... i was wondering if it had to do with the limitations of the colors or just how it reads. when I got conflicting numbers I used the one with the reagant and the powder that came with the TF-100. is that the one I should use daily until I am dialed in or is it reasonable to start with the blue kit? the one with the powder seems more accurate. it read 4 where I got 5 out of the blue kit. that's a bit disheartening. how good is the blue kit, then? or in the end is it ok since it was still in the range? thanku and yes, good time to review articles. trying my best time-wise.!

• To compare old kit from PB to blue kit....
  • set comparator blocks next to one another - Do the colors match?
  • add pool water and 5 drops of pH test reagent from PB kit to PB block
  • add pool water and 5 drops of test reagent from blue testkit to blue kit block - compare blue kit and PB kit - Do colors match and how do the reading compare between kits?
  • do the same with the chlorine test on both kits - be real sure NOT to mix up reagents or testing blocks between the two kits
• Temp will affect the reagents. How much, I don't know. I do know it's best to keep the kit inside when not in use. Also, the comparator block could have possibly lightened if left out in the sun for any amount of time - I had my original PB one do that.
• Until you are dialed in, I suggest you use the FAS-DPD (w/powder) as it will provide more accurate, precise results - which is exactly what you need to dial in the pump run time and SWCG.
• The blue kit is excellent for pH testing and also as an indicator (estimate) of chlorine in the pool. For more accurate results, always default to the FAS-DPD test.
• Always a good idea to review Pool School - especially when new to these methods. Even the "old-timers" here review and refer to it frequently.

While I can't seem to find it now - text looks blurry from staring at it for so long......
You asked somewhere about the difference in your CYA numbers and the one you got from the PS. Basically, the PS is incorrect more than not. If you've read many threads in this forum, you will find that not much credence is given to PS testing. Several reasons are given here for that believe. The most important is probably that no one is going to care for your pool as much as you do. The TF100 is the best kit out there - use it, believe your results and stay out of the PS (unless they have some cool pool toys you want).

 

[proavia]

Re: main drain has dirt and debri sitting in the bottom-no suction?

also, Kim mentioned the possibility of scaling? r we still yet to get to TA, Calcium, tips for how to keep pH at a good number like aeration...? i'll be reading, anyway. thx!

Scaling is usually from not keeping the pH adjusted properly (letting it get too high, as you did). ph, TA and CH factor into this. And with our hard water and high CH, it becomes increasingly important to keep the numbers balanced to reduce the possibility of scaling.

I think there's some stuff in Pool School about it. And we can discuss later - after you get everything else dialed in.
For now, keep FC above minimum, pH between 7.2 and 7.8 (on the lower side would be better as your CH is a little high already).

I run my pH at 7.2-7.5 as my CH is just above 600. TA is presently at 60. This helps keep my pool from scaling.

Like I said, more on this subject at a later date.

 

[proavia]

Re: main drain has dirt and debri sitting in the bottom-no suction?

Once again, my responses in Blue

just got an appt for the pop-ups for Friday morning. so, to get back to the original reason for my post: when people say their pop ups work, what does that mean? how long does it take, for example, for the pool to clean after a dust storm? what is left in the pool on a regular day like today after having run 4 hrs or whatever u set yours at. i've been brushing daily and pushing everything into the drain so i'll stop brushing now that the SLAM is done but even during the SLAM when i had my pump running on high for days on end I still brushed a lot of stuff into the drain. it especially seemed that way to me since I brushed at night a couple of times so u see all the flaws. my son must've had paper in his pocket and even that wasn't picked up by the next day until I brushed it all close to the drain.

• Mine run for 4 hours daily with pump on high speed. This total of 4 hours is split - 2 in the morning and 2 in the afternoon. And I run several additional hours on a much lower speed, which saves a lot of electricity and helps with additional skimming.
• You are still going to need to brush weekly as least. More often if necessary. I mostly just brush the pool walls - maybe the floors if I see something on them.
• Instill in everyone that nothing is to go into the water that shouldn't be there. Have them check there pockets, etc., every time before getting in.
• As an example, after that especially nasty 'Haboob' (big Monsoon dust storm - for those who are wondering) a few years back. I had about 1/4 inch of fine silt on the bottom. I ran the pump 24 hours a day for 2-3 days to get it all - this also included brushing the walls, and hosing the deck off (hose AWAY from the pool into the granite or grass). Normal Monsoon dust storm, I usually leave on normal schedule and it cleans in a day or two.
• On a "regular" day it's usually clean, sometimes maybe one or two small leaves.
• Always try to hose or blow debris AWAY from the pool, not into it.

those who say their in-floor works, how often do u brush and "help" the system. if u brush once a week, what's it look like by day 6? i always have some dirt on the floor around my drain. ALWAYS. i have some drip lines to bury next to the pool so i'm going to do it within the next couple of days so that if some dust/dirt gets in the pool we'll have a better gage to look at if it's picking stuff up or not. hoping for no dust storms before then, though cuz i'm sure they'll use that as an excuse. pb super said it could take a week to clean up a dust storm and it's not sounding like that's the experience of folks on this thread.

• I brush at least weekly (okay, sometimes I do lose track of time and forget) from spring through fall. And about every 2 weeks in winter - non-swim season.
• Usually by "day 6" it still looks good. Of course, if you're testing daily you will "see" how it's doing and adjust your brushing accordingly.
• Every pool is different. That being said, if it's advertised as keeping it 99% (or whatever number you cited earlier) clean - it should do that under normal conditions (no dust storms, no one throwing dirt into the pool, etc.).

they are also going to schedule someone for discoloration on the steps and what appears to be rust coming through. I think i posted pics way back on page one or 2. it's hard to get a good pic of the "discoloration" which i'm probably not calling it the right word. when i look at it standing on the patio it looks like the pebble is rubbing off. when i look up close on the 6" baja shelf it looks like I had bad luck with all tan pebbles landing in the one area that is probably 3 inches by 10 inches. on the second step, it looks like the plaster is coming off from around the pebbles but when i feel it I can't tell a bit. the same issue is found on the bottom step, all on the corners/inside edges where the step meets the side wall of the pool.
Could also be staining from a rusty nail sitting there for a day or two. Let us know what they say about it.

the rust they won't be able to deny but the areas where it's more white than other areas in the pool i'm thinking they'll tell me it's natural stone and that's how it happened to get sprayed out of their spray gun and it's never going to be perfect and i should've caught it within 30 days after pool was built. i can live with it if it's strictly cosmetic but i don't want it getting worse if it is something that is rubbing off cuz that's the appearance it has; as if something's rubbing off.
Could also be some minor scaling - but maybe not.

since we got so off track of my original post in this thread, if i should start this in a new thread, now pls advice. i know i've already gotten a lot of advice on this topic so far but want to be more prepared with an understanding of how folk systems work. or is there something like this already posted? specifically wanting to know how clean is clean and how long that takes for people. i'm impressed and thankful with the amount of reading, time, dedication folks are giving to help.
thanku!
I've seen it requested before by the higher-ups to keep everything in one thread for now. I think it's easier for them to decide if they want to split something off into a new topic. One exception to this is posting your issue/question in someone else's thread - even if your issue is the same, start your own thread.

 

[outdoorsgal]

great advice and I need to read about the relationship with CYA and FC more. my eyes are getting tired again but let me at least post what i tested tonight at 9:20pm before my salt cell/pump turned on. FC was 3.5 and pH remained the same as earlier today. i don't have it in front of me and too tired to search, but I think it was 7.5. i'll check again tomorrow. it'll be interesting to see how much it goes up after having the cell run and how much it goes down in the day. i'll want to retest my CYA soon, too, since I read that if you have to SLAM again u have to drain a bunch of water out of the pool to get the CYA out of the pool. do u know how long CYA lasts in a pool? Does it evaporate or diminish over time? thx. nite.

 

[needsajet]

I went back through the thread to get the TF100 test results. This is the TFP format for displaying test results, which makes it a bit easier than finding test results within a paragraph.

FC 3.5
CC
pH 7.5
TA 160
CH 625
CYA ~25 (some from prior additions, perhaps 10; ~17 added by ~2 lbs granular)
Salt 4400

CYA is very long lasting in the pool water and does not evaporate. It will also not increase unless it is added to the water.

 

[kimkats]

great advice and I need to read about the relationship with CYA and FC more.

Here is the science behind the CYA/FC relationship:

Pool Water Chemistry

Chlorine/CYA Chart


i'll want to retest my CYA soon, too, since I read that if you have to SLAM again u have to drain a bunch of water out of the pool to get the CYA out of the pool. do u know how long CYA lasts in a pool? Does it evaporate or diminish over time? thx. nite.

I think what you read is IF you have high CYA as in over 80 or so and need to SLAM you need to drain some water to lower the CYA. CYA stays in most pools until they are removed by water exchanges.

My answers are in purple. I hope this helps you understand the CYA/FC relationship. It is VERY in depth and really shows the science behind TFP's guides. There are more threads if you would like to read them. Do a search in the search box in the upper right. I used the words "CYA/FC chem geek" to find them.

Please note the chart is a more in depth chart for this one:

Pool School - Chlorine / CYA Chart

I strongly disagree with Josh (azjoshers79) when he says a FC over 5 is toxic. Please refer to the above information. If the CYA/FC chart is used to balance the water it is safe and sanitary to swim in.

I keep my CYA is kept at around 30 and I dose my FC to 7 each night before I go to bed. Yes that is higher than recommended in the CYA/FC chart BUT I know my pool and do NOT want to take a chance of falling below the min. FC of 2. My pool gets full sun all day AND lots of use by sweating, dirty bodies! Just yesterday I jumped in fully clothed in the middle of mowing my yard as I got hot. I got out and finished mowing, Then jumped right back in fully clothed again! I was sweaty, dirty, grassy, GROSS! When I tested my FC in the evening I was down to FC 4.

Kim:cat:

 

[kimkats]

I had forgotten about this one:

http://poolsolutions.com/gd/best-guess-swimming-pool-chlorine-chart.html

It is a little more user friendly.

Kim:cat:

 

[pooldv]

Re: main drain has dirt and debri sitting in the bottom-no suction?

Yes chlorine at high levels is absolutely toxic. I do not get in the pool or allow my kids to swim if chlorine is over 5ppm. I would finish the slam and let chlorine levels come down before swimming.

The above statement is false, see below.

PRoavia, I'll wait to learn more about the balance of CYA/chlorine levels. I never fully understood this and if I am raising my CYA to match a high amount of chlorine I don't want to raise my CYA anymore and want to learn more first. I have not been comfortable with and can't imagine I will ever be comfortable with a high level of chlorine. I dislike my pool now and the kids don't want to swim either. I'll look forward to an explanation of where this is going. I've decided I am sticking with lower levels of chlorine. I think the pool company said 3 and would have to go back to look at my previous kit. My son still has his headache today and my daughter was up til midnight complaining of her eyes burning not to mention what I've read about chlorine being a carcinogen. My intentions always have been and still will be to maintain a pool with the lowest level of chlorine as possible. If I need to have the CYA and chlorine balanced I will use my chlorine as a baseline and then match the CYA to that. I can imagine there may be times I need to raise the chlorine. That's what most people do, right? They shock their pools as needed? I need to read more I think but so far I'm not clear on what was wrong with the pb's method of keeping the pH and chlorine at their recommended levels. Since we never did a good job of that I never got a chance to see if it'll work. I look forward to hearing you out. Thank you.

- - - Updated - - -


azjoshers79. Thanku. that's always felt and I think at this point I need to go back to following that. I won't leave it at zero, but will leave it lower than 5.

- - - Updated - - -



how long should it take for the chlorine to get below 5 now that we've added the CYA? I miss my pool.

FC above 5 ppm is not automatically toxic, this is poor information without the context of the [FC/CYA][/FC/CYA]. It is very important to have at least 30 ppm CYA in the pool. In addition to protecting FC from the sun it also buffers the harsh effects of chlorine. FC is not what burns eyes or noses or smells like chlorine in a pool. That is CC and CC is worse in a pool with low chlorine than it is in a pool with correct levels or even high levels of chlorine. FC burns off CC and mitigates its effects. When you go to a public or indoor pool and it smells like "chlorine" and makes your eyes water just standing near it that is CC that you smell and burns your eyes. That pool is most likely regulated by a government agency and will have 0 CYA and a very tightly managed FC level of 3 and CC levels that are very high as a result of high bather load.

Having at least 30 ppm of CYA in the pool and following the [FC/CYA][/FC/CYA] will eliminate all of this. Last summer we needed to SLAM with our CYA at 70 which has a shock level of 28 ppm FC. We swam every day for over a week and nobody even noticed the elevated FC levels at 28 ppm. My wife and kids and I swam in it every day with no issues whatsoever. FC of 3 ppm with no CYA in the pool is significantly harsher than FC of 28 ppm with 70 CYA. Add to that 3 ppm any organic matter and CC will climb with insufficient FC to quickly burn off the CC and that makes for the textbook version of "chlorine" pool that everyone pictures.

Further, when FC drops below minimum for your CYA the kill rate of bacteria, viruses and pathogens becomes too low to effectively prevent person to person disease transmission, especially in kids. Chlorine's #1 job is to sanitize the pool and make it safe, killing algae is just a side benefit.

It is safe to swim when FC is between minimum and shock level for your CYA, [FC/CYA][/FC/CYA].

 

[needsajet]

At TFP, we normally explain FC/CYA from the perspective of keeping pools safe. We always want to be sure we have enough active chlorine to kill human pathogens, such as Escherichia coli. The TFPC system is built around this, using algae as an indicator. No algae, no pathogens.

But what if we explain it this way... TFP uses CYA to reduce the amount of active chlorine, so our water is nice to swim in, and we consume less chlorine.

Imagine the situation a bit differently. OutdoorsGal has a beautiful pool with a massive saltwater chlorine generator injecting chlorine gas into her pool 24 hours per day. It's a high tech sensor-based system with variable dosing and is recalibrated by a technician daily. She maintains her pool at 1 PPM FC and without CYA. Active chlorine would be about 0.5 PPM. The water chemistry would be somewhat equivalent to an exceptionally well run indoor aquatic center, with an active chlorine level not much different from city tap water, lower than some cities, but similar to most.

So the TFP representative comes along and says, hey, OutdoorsGal, we can keep your pool just as safe, kill the fecal coliform, make sure kids don't share their bacteria and diseases, and never let your pool go green. As a bonus, you're going to have much less active chlorine in your pool. Active chlorine is the part that is considered to be the "harsh" part. The part that ruins swimsuits. In simple terms, it's the part that exists as hypochlorous acid.

Under our TFPC system, your hypochlorous acid level will be about 0.03 PPM, less than 1/10th the level you're at now.

Here's how we'll do it. We're going to add cyanuric acid (CYA) to your pool. This process has been in use and, from a scientific perspective, well understood for over 40 years. It has not been widely explained by the pool industry because it's a bit complicated, and it really cuts into their chemical and equipment sales.

We'll be adding about 70 ppm CYA, which will hold chlorine in reserve, and release it as active chlorine, the hypochlorous acid. It will release active chlorine only as needed to do it's job as a sanitizer. You'll still lose some to sunlight, and that will be replenished in part from the CYA "reserve", but you'll be losing quite a lot less than you did without the CYA. The CYA will hold the vast majority of the chlorine in reserve, and the FC tied up in the buffer system registers on commonly available DPD tests, so we'll use a target level of 5 ppm FC to be sure we have 0.03 ppm active chlorine. Temporary dips are OK, but we'll set everything up so we never go below 4.5% of CYA, or 3.2 PPM FC, and 0.02 PPM active chlorine.

Active chlorine at 0.02 ppm is enough to prevent algae in the vast majority of residential pools. It's also more than enough to kill the vast majority of common pathogens that get shared between people in poorly sanitized residential pools.

There's some really big positives. Number one for you is that your pool will have far less (less than 1/10th) of the harsh hypochlorous acid in it, the active chlorine. Number two is that CYA is only seldom added, perhaps only once per year, and won't cost you more than 20 or 30 bucks a year. Number three is that you can turn down that massive salt water chlorine generator. Or even replace it with one you can buy online and run yourself.

Does that sound like something you'd like to consider?

 

[outdoorsgal]

wow. had salt cell at 100% because I was used to it "not producing." Proavia, now I understand that we probably always had algae that wasn't visible. FC this morning was 11 and CC 0 (noone went in the pool yesterday). hubbie's telling all of the kids to not go in the pool for a week. I'll watch the levels and I'm sure they'll be able to go in later. My son was sick for at least 30 hrs with the headache, staying in bed the whole time, not being himself and we started getting really worried. I was talking with someone who said they know a lot about chemistry and they said "chlorine poisoning? stick them in a tub with epsom salt and it will suck the chlorine out of his body and he'll be fine." that's what we did and he was fine. is it psychological? was it cuz he got out of bed? was it due to the epsom salt bath? i don't know and I realize we may have been swimming in high levels of chlorine before with no probs. all i can say is i'm glad we have a salt chlorinator since I'm sure most here would say it's the same chlorine, but I feel like there could be a different effect on my family with the chlorine that it made with the cell than the chlorine that is sold at the store. in the end, my husband is not comfortable with high levels of chlorine, nor am I so here we go in trying to figure out the lowest levels in a balanced pool.

pH was 7.8 so according to poolmath, to get it to 7.5, the # that is preset on the poolmath calculator, I'm going to add 14 oz acid, although the level of the MA that I have is 29%. I checked everything this morn at 8:50 and the filter still had 10 min to run. Typically we add MA when the pool is running. There's not the same danger of adding MA to a salt pool as far as having to wait 20 min until after adding chlorine, correct? I'm going to turn the pump back on for a while so I can add MA now but I put the cell on 100%. I'm thinking of seeing how the levels check out later and lowering the cell to 40% perhaps? I will read and respond to other posts later. thx

 

[needsajet]

I went back through your posts and it was very difficult to determine, but I believe you had some CYA to begin with (estimate of 10 PPM) and added 2 lbs and still have 2 lbs left to do. I estimated you have around 25 PPM CYA. This is important because CYA holds the vast majority of free chlorine in reserve, allowing much less than that in the water as active chlorine. It would be great if you could look back through your records and determine how much CYA (aka stabilizer, aka cyanuric acid) has been added.


To the best of my knowledge, you are not SLAMing currently, and under TFPC a minimum of 30 PPM CYA is recommended and the recommended FC target for that level is 4 ppm FC with a bare minimum of 2 ppm FC. If you're at 11, the SWG should be off to allow the FC to drop.

 

[kimkats]

You got a good test kit and learned how to use it! Good job! You are learning how to balance your pool using your test kit and Pool Math. NICE! You have SLAMmed your pool to a successful OCLT. SWEET!

With that I am closing this thread. We have given you all of the information we have to give to answer your questions. What you do with this information it now up to you. Here is hoping your pool stays looking like a jewel! :sun:

Kim