New pool owner, trying to get my chemicals balanced

[mitchryan912]

Hey everyone,

I'm a new homeowner and am new to maintaining a pool. I've recently taken 2 semesters of 100-level college chemistry and a 300-level organic chemistry, so I'm familiar with a lot of terminology and reactions going on in my pool. However, the previous owners of this home are my in-laws, so I'm getting some advice which I'm not 100% sure is correct, mainly that my father-in-law never did anything with adjusting alkalinity nor added any stabilizers.

ANyway, I've been going to a local pool store to get my water tested, and my first test read:

0 stabilizer
0 chlorine (it was burning off 1 gallon within 24 hours!)
7.8 pH
65 TA
120 CH

I followed their advice and added these chemicals, in this order:

.75 gallon of muriatic acid (31.25%)
3 gallons of 12.5% hypochlorite (this now seems high, but maybe ok?)
15 lbs of sodium bicarbonate
15 lbs of calcium carbonate (I have a vinyl liner, so I think this is unnecessary to add in the future)
5 lbs of cyanuric acid stabilizer

This treatment seems to do wonders for my pool, but we've since had a lot of heavy storms (a few tornados have blown through here in the midwest) and my levels are out of whack again. I did a chlorine shock (2.5 gallons) between storms and that held up for about 9 days until this past weekend. Now I'm trying to get things back in order, but I'm hearing conflicting advice at the store I've been going to (notably about shocking vs adding acid as the first step.)

That's it for now, but I'm sure I'll have follow up posts/questions in the future.

[mitchryan912]

As a follow up, 3 days after the treatment I described, my results ended up as follows:

15ppm stabilizer
1.0ppm chlorine
7.2 pH
120 TA
190 CH

A few days later, we believed there was an odd smell from the pool, so I was told to shock the pool with 4 gallons of chlorine (I only had about 2.5) to deal with the potential smell (it turned out something happened to our towels, which is where the smell came from.)5 days later, I had my pool checked again and my TA and pH went up (150 and 7.6), while my stabilizer disappeared (0 ppm.)

I then treated the pool with 2 quarts of muriatic acid, but we had a huge rainstorm which caused me to drain the pool down a few inches (about 1200 gallons, if I'm calculating it correctly.) This is where someone new to the pool store started running tests for me, so I'm not 100% sure if these numbers are right:

0 stabilizer
0.5 chlorine
7.6 pH
100 TA
160 CH

Is that normal for TA to go down while pH stays the same? I'm currently in need of lowering pH while keeping TA the same, but I'm not sure how to accomplish this?

[mitchryan912]

I am now a subscriber. Thanks!

[PoolDoc]

1. Get a K2006, so you can test it yourself. It actually sounds like you may be one of the very few who have found a pool store that tests water accurately . . . but the only way to know is to DIY. http://pool9.net/tk/ (Please ignore the booklet and wheel in the kit, at least till this fall!).

2. Transported samples of pool water may not have the same TA or pH as the same water in the pool, due to heating / cooling / aeration. See http://pool9.net/alk-step/ for an (indirect) explanation. Basically, if you want an accurate test of pH you must collect the sample in a bottle leaving ZERO head space (ie, cap it underwater) and (b) keep the sample temperature stable.

3. Depending on how they tested, the testing error for CYA levels at the low end can range from plus-minus 10 ppm (K2006 with experienced user) to plus-minus 50 ppm (eye-balled test strips). I don't know your pool volume, so I don't know what your CYA should have been after you added 5# . On a 30k gal pool, 5# would add 20 ppm. BUT, it dissolves slowly. People often 'lose' it backwashing before it dissolves. This most often happens when your pump is timer operated.

Next time, dissolve it in a sock in the skimmer OR use dichlor (9 ppm CYA for ever 10 ppm FC). (I know that doesn't add up; not going to explain while I'm behind on new users.)

. . . membership updated.

[Watermom]

Maybe I'm wrong but when I read your posts I got the idea that testing and making chemistry adjustments were things that were both happening periodically but not regularly. If that is the case, that isn't going to work. You have to tend it on a regular consistent basis like daily for now. After you learn how your pool behaves, you may be able to go a day or so between testing and adjusting but not now.

Welcome to the Pool Forum and thanks for the subscription!

[mitchryan912]

1. Get a K2006, so you can test it yourself. It actually sounds like you may be one of the very few who have found a pool store that tests water accurately . . . but the only way to know is to DIY. http://pool9.net/tk/ (Please ignore the booklet and wheel in the kit, at least till this fall!).
Working on ordering one, as NO ONE in town carries Taylor kits (one I don't frequent can get the 2006... for $99!) Yeah, I think the guy who did my first couple tests knows what he's doing, but then I went to the sales counter and was told to change the order of operations:

Test guy:
1. Shock the pool (3 gals chlorine)
2. Raise TA (15 lbs baking soda)
3. Raise CH (5 lbs CaCL2, 3 doses @ 8 hour intervals)
4. Adjust pH (1 qt muriatic acid)
5. Stabilizer (5 lbs CYA)

The sales guy's suggestion:
1. Adjust pH (3 qts muriatic acid, and I already had a gallon at home, so he didn't make an additional sale here.)
2. Shock the pool (3 gals chlorine)
3. Raise TA (15 lbs baking soda, all at once)
4. Raise CH (5 lbs CaCL2, 3 doses @ 8 hour intervals)
5. Stabilizer (5 lbs CYA)

I'm not sure what's the preferred order of operations here, as I've read conflicting things about what works? All I do know is that the store has a sheet they fill out when testing, and that the sheet says to go in the order of each item (maybe I'll scan it so you can see what I'm seeing.)



2. Transported samples of pool water may not have the same TA or pH as the same water in the pool, due to heating / cooling / aeration. See http://pool9.net/alk-step/ for an (indirect) explanation. Basically, if you want an accurate test of pH you must collect the sample in a bottle leaving ZERO head space (ie, cap it underwater) and (b) keep the sample temperature stable.
It's a 30 minute drive to this particular pool store, but I often am heading straight there after I take a sample.



3. Depending on how they tested, the testing error for CYA levels at the low end can range from plus-minus 10 ppm (K2006 with experienced user) to plus-minus 50 ppm (eye-balled test strips). I don't know your pool volume, so I don't know what your CYA should have been after you added 5# . On a 30k gal pool, 5# would add 20 ppm. BUT, it dissolves slowly. People often 'lose' it backwashing before it dissolves. This most often happens when your pump is timer operated.
I think I've gotten myself frustrated because I just bought some AquaChek yellow test strips, and was told these should get me in the ballpark but wouldn't be totally accurate. My test strip shows pH 6.8 while my cheap pH test (with phenol red) shows pH 7.6. Granted this is after adding acid and chlorine over the past 24 hours, so I don't expect either of them to be accurate, but was hoping for them being close to each other.

I have a 26,000 gallon pool, and was told to not backwash for 3 days after adding CYA. I've been backwashing, rinsing, and sending out extra water to waste (lots of rain lately) before I do any major adjustments, so I don't lose anything I've just added and so that my skimmer actually skims. :)

Also, I don't have a timer, so the pump runs 24/7. I don't know if this is a bad thing for anything outside our electric bill? I don't have a way of changing it to add a timer unless I revamp ALL my home's electrical paneling (I'm a former electrician, and the main panel is ancient and wired WAY out of code, much less the "sub panel" the pool pump is wired to.)



Next time, dissolve it in a sock in the skimmer OR use dichlor (9 ppm CYA for ever 10 ppm FC). (I know that doesn't add up; not going to explain while I'm behind on new users.)

. . . membership updated.
Thanks, I'll give that a shot next time.

[mitchryan912]

Maybe I'm wrong but when I read your posts I got the idea that testing and making chemistry adjustments were things that were both happening periodically but not regularly. If that is the case, that isn't going to work. You have to tend it on a regular consistent basis like daily for now. After you learn how your pool behaves, you may be able to go a day or so between testing and adjusting but not now.

Welcome to the Pool Forum and thanks for the subscription!

Thanks! Yes, I've been checking it was a cheapo $10 OT/PR test kit every day, but since I'm new to understanding how much of each chemical affects the system (notably high chlorine & pH), I've been doing my own tests PLUS making trips to my pool store every 3-5 days to have them do a full workup. All the gas plus unneeded chemicals adds up to making a K2006 worthwhile, so I'll be getting one of those to check levels daily.

That said, is there a sticky for intervals between adding a chemical and when it's either A) safe to swim or B) your test kit will be accurate in its measurement? My father-in-law used to shut the pool down for the day whenever he'd add anything, but now that we own the house (and have kids that want to use it!), we don't really want to have down days unless it's a rainy or cold day.

[Watermom]

Trust your OTO/Phenol Red kit over the test strips. Order the Taylor K2006 or 2006C (better buy) from the link that Ben provided above as soon as you can. It will make things much easier.

As long as you have a pH reading between 7-8 and some chlorine in there, you can swim. We'll need some numbers that the K2006 can provide to better be able to advise you on needed levels. Chlorine is dependent on CYA readings. Take a look at the chart at this link for more about this relationship:> http://pool9.net/cl-cya/

With your OTO kit, if your chlorine is over 5ppm, you can use this chart to interpret off the scale colors:> http://pool9.net/oto-chart/
Your pH will be inaccurate if your chlorine is over 5ppm (or over 10ppm with the Taylor kit). So, if you have high chlorine, you can dilute your test sample 50/50 with pool water and distilled water and then test pH with that mixture.

[PoolDoc]

Trust the cheapo OTO/phenol red drops kit. Ditch the AquaCheck strips.

=> *ORDER* the K2006; we've still never heard of a pool store carrying these. (Why would they stock a kit that will tend to put them out of business.)

=> Any pool store that tells you to add calcium to a vinyl pool is not to be trusted: they are selling you chemicals that are worse than useless in your pool, since they have NO benefit, but can cause problems.

=> If your pH is between 7 and 8 --AND-- your chlorine is greater than 1.0 OR 10% of the CYA level, whichever is higher --AND-- you haven't added any funky chemicals like foamy algaecides, mustard algae treatments or non-chlorine shock . . . it should be fine.

=> Wait time after adding chemicals is often 5 minutes, but it depends on your pool, where you added them, what you added, and how the pool circulates. If you want a safe number that's pretty much arbitrary, but almost certain to be safe, then go with "1 hour after chemical additions WITH THE PUMP ON and CIRCULATING".

[PoolDoc]

Ugh. Another simul-post!

[Watermom]

Hey -- getting two answers is better than getting none! And, at least we pretty much said the same thing! ;)

[mitchryan912]

Thanks! Just ordered the K2006 through your Amazon store/link. I won't get it in time to measure for this weekend's pool parties, but the store I'm using is willing to perform 5 free tests, so I used the last one today. Thankfully they said that my levels went from (and to) this over the past few days:

0 to 15ppm stabilizer (I added 5 lbs of CYA)
0.5 to 5ppm TC (I added 2.5 gallons of 12.5% hypochlorite)
7.6 to 7.2 pH (I added 2 quarts of muriatic acid, 31.25%)
100 to 110 TA (I added 4 lbs of baking soda after I *thought* that I added 1 quart too many of acid)
160 to 160 CH (didn't touch this)


Trust the cheapo OTO/phenol red drops kit. Ditch the AquaCheck strips.
Yeah, those strips were showing my pH at 6.8, but I think they could be handy for stabilizer and/or TA until I use them up.


=> *ORDER* the K2006; we've still never heard of a pool store carrying these. (Why would they stock a kit that will tend to put them out of business.)
So it turns out that the store I've been going to DOES indeed carry the K2006. They're all behind the counter, so I never noticed them until today. However, I called them yesterday afternoon and asked for it (specifically), but they asked if I had a commercial pool or not. When I said no, they suggested another kit instead. They totally missed out on a sale of ANYTHING because of that! Granted I saved $20 by buying it from/through you guys, but the impatient side of me would have thought it was worthwhile to get it and not have to wait for the K-2006 to ship here.

EDIT: Either way, it's good to know they have the kits AND all the replacement vials, should I run out or need to replace some of the test chemicals next year (I assume some chemicals in the Taylor kit are only good for one season?)


=> Any pool store that tells you to add calcium to a vinyl pool is not to be trusted: they are selling you chemicals that are worse than useless in your pool, since they have NO benefit, but can cause problems.
I mentioned that today when they said I have a vinyl lined pool, but they said that my 160 ppm CH was fine, but they I don't want it to drop too low (it was 120 ppm when the pool opened, so I'm not sure it's going to get too low?)


=> If your pH is between 7 and 8 --AND-- your chlorine is greater than 1.0 OR 10% of the CYA level, whichever is higher --AND-- you haven't added any funky chemicals like foamy algaecides, mustard algae treatments or non-chlorine shock . . . it should be fine.
My father-in-law added algaecide when we opened the pool, but I think it was some standard, good quality stuff. Nothing funky. IIRC, it was a blue liquid that he walked around the whole pool.


=> Wait time after adding chemicals is often 5 minutes, but it depends on your pool, where you added them, what you added, and how the pool circulates. If you want a safe number that's pretty much arbitrary, but almost certain to be safe, then go with "1 hour after chemical additions WITH THE PUMP ON and CIRCULATING".
That sounds good. That sounds reasonable, or at least much more reasonable than "I added [insert chemical here] today, so you can't swim," which is what we used to hear when we wanted to swim here when my in-laws owned this house (before we bought it last year.)

[Watermom]

Just a couple of quick comments for you:

Actually, the test strips are terrible at giving an accurate CYA reading.

Your pH at 7.6 was fine. No need to have added the muriatic acid.

I have a feeling the pool store had a K2005 kit and not a K2006. They are not the same thing and you don't want a K2005. The reagents should still be fine next year.

[mitchryan912]

Just a couple of quick comments for you:

Actually, the test strips are terrible at giving an accurate CYA reading.

Your pH at 7.6 was fine. No need to have added the muriatic acid.

I have a feeling the pool store had a K2005 kit and not a K2006. They are not the same thing and you don't want a K2005. The reagents should still be fine next year.
So... test strips in the trash when my K2006 arrives? It was definitely a K-2006. The woman who's been doing my testing even opened it up and showed me everything inside it.

Does keeping pH lower help with drying out skin? I was getting SUPER dried out when pH was testing out closer to 7.8, but I wonder if TA being as low as 65 could have been the culprit as well?

[PoolDoc]

Water dries skin -- removes skin oils -- regardless.

High chlorine (FC > 25% of CYA) leaves my skin feeling 'dry' and 'tight', so that might be what you were experiencing. But I don't think everyone's skin is the same in that regard.

Many people report that their skin feels 'less dry' when they begin using salt (NaCl > 2000 ppm) or borates (> 60 ppm). Some people have added salt, just for the feel. Again, their 'dry' skin may not be the same thing you are experiencing. Regardless, I'd try borates first. Salt does increase corrosion, and I'm not sure it's worth it, if you don't have a SWCG.

The saponification (oil => soap) of oils *is* affected by pH, but I don't know if the the difference between 7.4 and 7.8 or 8.0 would be enough to notice. However, it surely won't hurt to lower your pH and see.

[mitchryan912]

3. Depending on how they tested, the testing error for CYA levels at the low end can range from plus-minus 10 ppm (K2006 with experienced user) to plus-minus 50 ppm (eye-balled test strips). I don't know your pool volume, so I don't know what your CYA should have been after you added 5# . On a 30k gal pool, 5# would add 20 ppm. BUT, it dissolves slowly. People often 'lose' it backwashing before it dissolves. This most often happens when your pump is timer operated.

Next time, dissolve it in a sock in the skimmer OR use dichlor (9 ppm CYA for ever 10 ppm FC).
I just wanted to follow up on this. My store recommends dumping all 5 lbs into the skimmer, with both the skimmer and pump baskets removed while it circulates. They also warn STRONGLY not to backwash for 3 days after adding CYA. Is this something that sounds right?

If I dissolve it in a sock (a regular sock?), does this change anything with those recommendations?

EDIT: FWIW, I have a ~26k gallon pool and adding 5 lbs on Monday brought me up to 15ppm of CYA on Wednesday.

[PoolDoc]

Their recommendations are about right, if your pump runs 24/7. Otherwise, not so much.

The only reason to clean the pump / skimmer basket is to keep you from dumping stabilizer out when you clean them. If you clean the pump and skimmer basket first, on most pools they won't need cleaning again till after the CYA is fully dissolved.

On a 26k gal pool, 5# of CYA fully dissolved will give you 23 ppm of CYA, so a measured level of 15 ppm is well within the range of error.

[Watermom]

If you put it in a sock in front of a return, you don't have to worry about throwing it out when you backwash.

[mitchryan912]

I bought another 5 lbs at my last trip to the store, just to save a trip. Should I put some of this in (dissolved in a sock) to bump it up a bit, or should I save it for the inevitable rain storms that have been hitting the midwest? I was told that stabilizer should last a whole season, but with all the draining and backwashing I've had to do after storms, I'm sure I've lost a lot of it.

[PoolDoc]

When you are having to drain and backwash a lot, a sock would be better, to keep you from losing it.

A better solution for you may be to buy dichlor at Sams Club. They have a 24# pack and a 50# bucket for very good prices. Each pound of dichlor will add about 3 ppm chlorine, and about 2.5 ppm of CYA . . . and it dissolves almost instantly.

[CarlD]

I find it both sad and hilarious that a pool store wouldn't see you a K-2006 even at an inflated price. I'm guessing they want you to use one of the junkier kits and have to come them for proper readings. Inane. Like a tool store recommending you buy a bargain brand hammer rather than an Estwing. That fact that they stock the K-2006 is pretty amazing but if they stock them for the pros I'm surprised they don't stock the K-2006C instead.

Just yesterday I had to buy some CYA at a local store and the young saleswoman tried to tell me the alkalinity raiser was a "special" formulation of Baking Soda, as if it wasn't NaHCO3! "Yeah, right. I just need the CYA."

[mitchryan912]

I find it both sad and hilarious that a pool store wouldn't see you a K-2006 even at an inflated price.
Higher profit margin on the cheaper ones? Thats one big reason I could see, but I suppose that they don't expect their average customer to know much (if anything) about chemistry and/or how to use a more advanced test kit.


That fact that they stock the K-2006 is pretty amazing but if they stock them for the pros I'm surprised they don't stock the K-2006C instead.
I didn't ask if they had the 2006C. I had already ordered the 2006A earlier that day, so the only thing I was concerned with by then, was what they had in stock for replacement vials for next year.

This store might not be an anomaly by carrying the K2006, as Wisconsin Dells is just 40 minutes north of here. "The Dells" is a small tourist town (population <3000) that boasts a whopping 5 indoor and/or outdoor waterparks and 2 of the top 10 largest waterparks in the country. That might have something to do with it, as where I live probably doesn't have any more or less pools, be it public or private.

[PoolDoc]

We still haven't got a confirmed case of a pool store selling either a K2006a or a K2006c .

The purpose of these kits is to enable people to bypass pool stores; it's hard for a pool store to get enthusiastic about that sort of product!

[mitchryan912]

We still haven't got a confirmed case of a pool store selling either a K2006a or a K2006c .

The purpose of these kits is to enable people to bypass pool stores; it's hard for a pool store to get enthusiastic about that sort of product!
Midwest Pool Supply in Middleton, WI
(608) 831-5957

Hopefully that's not considered spam, but considering they sell their K-2006A kits for $80, I doubt anyone is going to buy them over ordering through your Amazon store.

Anyway... for people like us, I'm sure that damn near all pool stores would rather us trust them and their in-house test measurements. For the average homeowner who doesn't have the chemistry background nor the time to deal with pool maintenance, I'm sure they'd be just fine with a basic OTO/Phenol kit. I'd guess that the average homeowner who thinks its cool to have their own pool but can't maintain it probably just hires someone to do so, right?

When we bought the house back in October, I was VERY nervous about maintaining the pool, especially the mechanical side. Once I realized it was pretty simple chemistry, I felt like I might be able to handle it. Once I realized that the stuff I'm putting in the pool isn't nearly as dangerous as my father-in-law claimed ("I put in acid last night, so you can't swim today"), I felt like this wouldn't be too difficult to do. However, let's see what happens when I have to close the pool this fall. :)

[PoolDoc]

Do they stock the kits . . . or are they simply ordering them on demand?

[mitchryan912]

Do they stock the kits . . . or are they simply ordering them on demand?
They had at least 4 in stock, which is how someone was able to open one up and show me what was in it. I'm guessing they only stock them for commercial pools, as I've been discouraged TWICE from buying one (the first time I went in, I asked about a test kit for checking alkalinity, to which they suggested bringing in a water sample for them to test.)

[PoolDoc]

Interesting.

[mitchryan912]

Indeed it is, and they totally lost a sale by trying to sell me something else (over the phone.)

Oh well, my K-2006 is in the Chicago FedEx facility, and should be delivered by tomorrow at 8pm. :) It's perfect timing as I had to refill the pool (somehow lost a ton of water over the weekend) and will need to shock and adjust the pool this week to be ready for another big pool party this coming weekend.

[mitchryan912]

My K-2006 arrived today! I had to fill up the pool with the hose and had a rainstorm last night that added a bit of water. Interesting results from my first test:

7.4 pH
3.5 ppm TC
110 ppm TA
50 ppm CYA

I wasnt expecting these results at all, considering how much water was added after losing a lot over the weekend (~1000 gallons.) I last added acid, chlorine, & CYA about 8 days ago. My last test (7/3) at the pool store showed similar results, except for the CYA:

7.2 pH
5 ppm TC
110 ppm TA
15 ppm CYA

I backwashed a bit Saturday AM, and accidentally had something go wrong with putting the valve back to filter, and lost ~750 gallons. As such, I did NOT expect to see such a high CYA reading. Granted there could be some operator error involved, but I recently took a ton of college chemistry and biology classes (and had pretty good lab technique & grades), so I'm not sure if I did it grossly wrong. I will note that I'm taking the sample from the point of the pool where it starts to slope down to the deep end (the samples I had been taking to the store were all from the deep end.)

Just curious what to make of these and if I should shock the pool again this week?

[Watermom]

How does your water look? Why would you need to shock? You do need to add some chlorine so your chlorine levels don't drop below the minimum required based on your CYA ( http://pool9.net/cl-cya/) but not sure why you think you should shock.

[mitchryan912]

How does your water look?
Looks crystal clear, but there's a layer of stuff on the bottom of the pool that keeps coming back, as soon as a day or two after vacuuming. Some of it obviously is grass clippings and bits from the arbor vitae trees that line our property line, but the other stuff... I'm not sure if the stuff that tends to pile up along the liner seams is dirt clusters or not.


Why would you need to shock? You do need to add some chlorine so your chlorine levels don't drop below the minimum required based on your CYA ( http://pool9.net/cl-cya/) but not sure why you think you should shock.
I thought it was good form to shock after a heavy rain and/or every 10-14 days. Is the latter idea a pool store gimmick to increase chlorine sales? Either way, I think a goal of 3-5 sounds good to me since I'm not sure if my CYA level of 50 is correct. Is keeping it in this range as good as shocking it every so often?

For backwashing purposes, is it a big deal to have that much chlorine in the water that's being pumped into the street (and thus into the lakes)? My FIL said that it's best to backwash and rinse when the chlorine gets down to near zero so it doesn't kill the grass in the front of our property (the filter waste line goes from the backyard to the driveway, where it mostly goes into the street but some of it goes down the sidewalk.) I'm curious if that's good advice or not?

[Watermom]

As long as your chlorine never drops below your minimum per the CYA/Chlorine chart, you really don't ever have to shock the pool. Honestly, I seldom do. Of course the pool stores and pool chemical bags tell you to do it weekly to increase sales!

I have never had an issue with grass being killed from backwashing into my yard.

Regarding the stuff that keeps reappearing along the seam lines, it may very well just be dirt. I see the same thing in my pool. I vacuum very slowly and it appears to all be gone but then when the water quiets back down, it is inevitable that there will be a little dirt that had gotten into suspension that will resettle to the floor around the seams. Its no big deal. Much as we want to, it is impossible to keep an outdoor pool totally dirt-free.

[mitchryan912]

OK, that sounds good and is good to know about how clean to expect to see the bottom of the pool.

I'm using PoolCalc on my iPhone to figure out how much chems to add. It says that to raise FC from 3.5 to 5.0 in 26k of water, that I should add just a touch more than 1 quart of 12.5% chlorine. Granted I probably should have added it last night instead of now (tons of direct light on the pool in the early AM to about 3pm), but I hope to see it get close to 5ppm in the next hour to two.

Now that I have a K-2006, how often should be checking the levels? I'm assuming FC & pH should be daily, but how about CYA & TA? Should I ever need to bother with checking CH since I have a vinyl liner pool? Should I post these questions in the FAS-DPD forum?

[Watermom]

Check chlorine and pH daily. CH doesn't need to be checked as long as your CH is low and you aren't using any products that add calcium. CYA only needs checked if you are adding CYA directly or using dichlor or trichlor. Otherwise once a month is fine. TA once every couple of weeks unless your pH starts bouncing around.

You don't have to use your K2006 daily. For those quick chlorine and pH checks, you can just use an OTO kit and then use the big kit maybe once a week.

[PoolDoc]

Strip based testing of CYA is HORRENDOUSLY inaccurate.

Watch the video of the Taylor CYA test if you want to validate your testing: http://pool9.net/tk/

[mitchryan912]

Strip based testing of CYA is HORRENDOUSLY inaccurate.

Watch the video of the Taylor CYA test if you want to validate your testing: http://pool9.net/tk/
I've tossed the strips and received a K-2006, so the reading of 50 ppm CYA is from my Taylor kit. It could be inaccurate, since it was my first time performing the test.

[mitchryan912]

Regarding the stuff that keeps reappearing along the seam lines, it may very well just be dirt.
I discovered that it's actually mostly sand. I usually close my eyes underwater because the chlorine irritates my contacts, but used some goggles and got a close up view this evening. I wonder if that's coming from the filter?

[mitchryan912]

Check chlorine and pH daily. CH doesn't need to be checked as long as your CH is low and you aren't using any products that add calcium. CYA only needs checked if you are adding CYA directly or using dichlor or trichlor. Otherwise once a month is fine. TA once every couple of weeks unless your pH starts bouncing around.
I ran another batch of tests today, just to get some practice doing them and to see how accurate my first readings were a few days ago. I also added a few hundred gallons of water (had a leak I fixed (http://www.poolforum.com/pf2/showthread.php/25325-How-much-water-is-normal-to-lose-to-light-use-amp-evaporation?highlight=)) and 12.5% liquid chlorine last night (2 quarts) plus some liquid acid this AM (2 quarts), and got this at noon:

7.2 pH
5 ppm FC (0 CC)
100 ppm TA
45 ppm CYA

I think this sounds about right, considering the previous test.


You don't have to use your K2006 daily. For those quick chlorine and pH checks, you can just use an OTO kit and then use the big kit maybe once a week.
What do you recommend for OTO kits for chlorine accurate to around 5 ppm? The one I have only shows up to 3 ppm FC. What about phenol red that's accurate with up to 6 ppm FC? Would a K1000 work, or would it be just as good to use the K-2006 since the phenol red in that kit won't last over the winter anyway? Since we're in Wisconsin, we probably only have 2 months tops of swim time left, so a new .75 oz phenol red indicator vial should last until early October, right?

[PoolDoc]

The Taylor K1000 is available from Amazon: http://pool9.net/tk/

You can see the extended OTO range here: http://pool9.net/oto/


I wonder if that's coming from the filter?

Unless you live in a coastal area, or have a sand box for your kids / grand-kids -- it's probably coming from your filter. Vacuum it up, and see if it keeps entering the pool. If it does, you'll have to dig into your filter. But if it's not bad, I'd wait till fall.
.

[mitchryan912]

Just thought I'd post a follow up with my testing results. I feel pretty confident in how my testing is going and how much of [insert chemical here] effects various water levels. The only thing I'm not sure of is how much (if any) baking soda should I be adding, or is it something that you get right once and it's then mostly OK? Here's a little spreadsheet I've been using to track how things are going, along with some notes about weather conditions. We didn't use the pool much last week due to the "polar vortex" that dropped our nighttime lows down in the 40's.

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While I'm posting this, I thought I'd ask about how much effect temperature has on the chemicals and levels in a pool? From what (I think) I remember about college chemistry, higher temperatures tend to make reactions happen faster, but I'm not sure if +/- 5 degrees is enough to drastically change anything?

[PoolDoc]

Your TA is not an issue with a vinyl pool. The only reason to add more -- in your case -- is if you find the pH becoming unstable and fluctuating quite a bit.

[Watermom]

+/- 5 degrees isn't really gonna matter as far as your pool goes.

[mitchryan912]

So I'm pretty much OK, especially considering the water looks fantastic?

[Watermom]

Your chlorine has dipped a little low a few times. Keep it within the minimum/maximum range based on your CYA and you'll be fine. Otherwise, everything looks fine.

http://pool9.net/cl-cya/

[mitchryan912]

Your chlorine has dipped a little low a few times. Keep it within the minimum/maximum range based on your CYA and you'll be fine. Otherwise, everything looks fine.
Yes, I've been trying to do that, but suddenly the ability to retain a good level of chlorine stopped, and chlorine has been disappearing a lot faster than before. I added a bit of info from before the 8th of July, when I got my K-2006 kit:

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We had a good bit of daily rain from the 9th to the 15th, and somewhere in there I had a filter valve leak where I slowly lost about 1000 gallons. Diluting the pool with fresh water probably had something to do with the change in stability, but I'm not sure what else could have caused it, other than not putting as much chlorine in daily or every other day in that rainy period?

I was using an OTO kit between July 2nd and 8th, and it was VERY dark yellowish every day in that time frame, so the chlorine was holding up well, though I admittedly don't have an very good idea of exactly how much chlorine there was.

[Watermom]

but I'm not sure what else could have caused it, other than not putting as much chlorine in daily or every other day in that rainy period?

Yep. That'll do it. We see it all the time. Usually it is people who come onto the forum and tell us that the rain caused their algae which isn't the case. Usually it is because people aren't as diligent about keeping tabs on their pool when it rains.

As long as you are aware and watching to keep your chlorine levels in the proper range, you'll be fine.

Hope this helps! ;)

[mitchryan912]

Yep. That'll do it. We see it all the time. Usually it is people who come onto the forum and tell us that the rain caused their algae which isn't the case. Usually it is because people aren't as diligent about keeping tabs on their pool when it rains.

As long as you are aware and watching to keep your chlorine levels in the proper range, you'll be fine.

Hope this helps! ;)
I guess I got complacent over the course of the first 2 weeks of July where it stayed above 3.0 ppm, where I didn't really add too much chlorine except for a 2.5 gallon shock on the 1st, some amount on the 9th (probably a quart or two), and then some before a big pool party on the 12th.

I'll keep a better eye on it now so I don't come back with algae problems in the future! :D

[mitchryan912]

I went back and tracked the weather in the timeframe my FC levels were quite stable, and I think I can conclude 2 things:

1. FC stayed stable because there were a TON of cloudy & partly cloudy days here in the beginning of the month.
2. The chlorine I've been using since the 1st has been some bargain deal chlorine from Menards that was on sale for $1.99/gallon.

I'm guessing that the former helped considerably, but the latter... I think the 12.5% chlorine I've been using lately isn't actually the 12.5% that it's advertised as. I put in 1 gallon earlier today, and it only raised FC up from 2.0 to 4.5 ppm. I added another 2 qts about an hour ago, and will be testing it before I go to bed and then again in the AM, to see if there is anything funny going on.

EDIT: Just checked FC at night before bed, and it's up to 8.0 ppm, which is in line with what you'd expect with 10% chlorine (2.0 to 8.0 via 6 quarts.)

[Watermom]

You will definitely use less chlorine on cloudy days. And, I agree with you that 1.5 gallons (6 quarts) would raise your chlorine by about 6ppm if it were 10% sodium hypo. It is pretty typical for many of the bottles of liquid chlorine to not be the strength they are advertised. That will be especially true if they sit on a shelf for awhile in a hot store. That is one reason we like Walmart's generic bleach. They have a fast turnover and the bottles are in an air conditioned store which further slows the break down.

[mitchryan912]

My morning chlorine level was at 7.5ppm, so that seems like a reasonable amount of chlorine loss, especially if there might have been anything trying to bloom when the chlorine dropped low. We're expected to hit 90 degrees for the first time this year, so I'll be watching it like a hawk and probably doing a second test this evening to see how it's changed over the day.

I think I'll be going back to the pool store for 12.5% after I use up the remaining 3 gallon jugs I bought at Menards. I'm not even sure that the jugs I used previously were 10%, considering how ineffective at least one of them was. Roughly 2.5 gallons out of Midwest's 5 gallon jugs brought me from .5ppm to 5ppm 2 days later (and both measurements were done at Midwest, so who knows how accurate those were.)

This brings up a question I've been wondering about the "Best Guess" method: assuming a pool with 40 CYA, is <4 ppm FC pretty much equal to a pool with 0ppm CYA and 0 FC? If this isn't clear, does the CYA effectively bind up a lot of the chlorine such that it's there, but not always available until the CYA-chlorine bond separates? I guess I'm just curious why there is a minimum of 3ppm when CYA is between 30-50ppm?