My readings

[josephny]

Not having a proper (accurate, reliable) test kit yet (it's on order), I filled a clean Mason jar and went to the nearest pool supply place.

The nice gentleman there ran his tests (using a computer attached to a device in which vials of my water and his testing chemicals were placed) and we got the following results:

Chlorine: 5.33
Free Chlorine: 5.33
PH: 7.8
Hardness: 40
Alkalinity: 90
CYA: 20

So my multiple brands of strips as well as the tube-chemical-mixing tester weren't too off in leading me to think my chlorine was too high.

So here's my questions:

1) Is it dangerous to swim in this water (I have 3 little kids)?
2) The pool store guy said the CYA test will be off because of the high chlorine level. Is this correct? Can I nevertheless be comforted that my CYA is not high enough so as to require a water replacement?
3) The pool store guy said I should remove my floating chlorinator with trichlor as well as the pool cover and monitor the chlorine level -- it should go down.

But, I'm only at this location every 5-7 days (otherwise, I'm 100 miles away).

Pending testing with the TF100 (which I won't be able to use until the next time I'm here, which will be a week from today), what's my best course of action?

Thanks very much,

Joseph

 

[PaulR]

1) It's safe. The Pool Calculator shows a range of FC 2-5 for CYA 20, you're fine.
2) His CYA test, maybe. The TF100 CYA test is unaffected by FC level. If anything CYA 20 is too low.
3) I'd keep the pucks and floater. How many tabs did you put in? In my pool, two tabs and a solar cover is enough to maintain a level, and yours is smaller, so I'd think you wouldn't want more than two tabs. (If I'm wrong and your FC is 1 next week, you get to flame me!)
--paulr

 

[josephny]

Thanks, Paul!

Very (very) happy to hear it's safe to swim. I checked the Chlorine/CYA chart which says that a CYA of 20 has a minimum of 2 and a target of 3. I'm having a hard time figuring out to use the calculator to show a safe FC level for a given CYA.

Funny (sort of), I just walked back in to the house from dragging the cover off and the floater out -- and it's pouring rain.

Okay, back out to put the floater in. I've always put 3 tablets in. I'll put 2 now.

What would be very annoying is to come back next week and find a nice green slimy pond because of no chlorine. (That is to say, I'd rather come back and tell you you were absolutely right!)

Thanks!

 

[PaulR]

let's hope I'm right, then!

re the calculator, put in your gallons; your CYA level in the "now" column; then down near the bottom of the colored section you tell it you have vinyl. Then scroll back up to the FC row and it will show you the target range.
--paulr

 

[dmanb2b]

yes...I would keep the trichlor given your low cya level...watch that PH...you really do not want it going above 7.8.

Welcome to TFP...we are basically neighbors

 

[frustratedpoolmom]

Hi and Welcome.

The pucks should keep the PH in check - they are acidic and lower ph. Actually, to keep the PH from getting too low over time, next time you're out I would add enough Baking Soda to raise your TA to 120. This will help keep the PH from dropping too low. But retest next week, if the ph is dropping, then add the baking soda. If your numbers are otherwise stable, no need to adjust it. Hope that makes sense.

 

[josephny]

I got my new TF100 test and it is indeed very fine -- a large single layer multisection parts box with everything clearly labeled and available.

Of course, in my excitement I didn't see the CYA-water mixing bottle nor did I notice the measuring bottle marked "Chlorine only"

I used the other mixing bottle -- I hope that doesn't mess anything up.

Here's my numbers as of 5 minutes ago:

FC 4.5
CC 0
PH 7.2
TA 140
CYA 80

Now I'm pretty confident in all my readings except the CYA. I did it twice (looks like I'll run out of the CYA reagent before summer ends), but I'm just not sure of exactly how disappeared is disappeared (with respect to the black dot, of course).

So how bad is my CYA and why would the pool store (with it's fancy machinery) say my CYA is 20?

I see the pool calculators says my FC should be 6 to 11. I'm so reluctant to raise it because of the years of reading and being warned that anything above 3 is dangerous to humans.

It's interesting to see how the numbers changed in 6 days of not touching the pool (with a floater with 2 trichlor tabs in it).

Any help would be very appreciated.

Thanks,

Joseph

 

[reebok]

http://www.taylortechnologies.com/Chemi ... ntentID=36
trust your numbers. cya is a monthly test. you shouldn't run out too quickly. unless virtually every member of this board is a zombie, the chlorine/cya chart is perfectly safe I had the same misgivings, esp with a 10 month old, but I keep my fc at 8 with cya of 70 and all of us have been fine.
pool-school/chlorine_cya_chart_shock

 

[PaulR]

reebok gave you the link to Taylor's pictures of the CYA test. You want to be unable to tell where the black dot leaves off and the white circle begins. When I'm getting close to that point I wiggle the tube a little because eyes are better at catching motion/changes, often I'll think ha! that's where the dot is, and keep going. Also the optimal light for CYA is outdoors with your back to the sun, i.e. good light but not direct sun.
--paulr

 

[josephny]

Those are great pics -- Thanks!

As for wiggling the tube, that's a good idea. Do I understand correctly, then, that the reading should be taken when I absolutely (100%) cannot see the dot?

As to going forward, does it make sense to add liquid chlorine (Chlorox Bleach from a supermarket, right?) when I'm around and use the trichlor tabs when I'm not so as to not raise the CYA as much?

I'm really hoping my cya isn't 80 at the start of the season -- ugh!

 

[PaulR]

Yes, the black dot should be completely obscured.

Regarding absentee chlorination, the pucks will make you slowly accumulate CYA over time. In this situation the key is "slowly." Each puck costs you about 2ppm CYA. If you were starting from 40, you'd need to use up 20 pucks before you got to 80. You probably aren't using as much as 2 per week so we're talking probably 3 months to get that far. In NY that's probably a whole season.

Here's another thought--because you have a cover, your daily FC loss would be lowered, so maybe you could shock with bleach right before you leave, then use only one puck in the floater.

Food for thought,
--paulr

 

[duraleigh]

I used the other mixing bottle -- I hope that doesn't mess anything up.

Not a problem. Over time, the chlorine testing cylinder will develop a black (dark) residue that would not be good to use for the other tests.......that's why we provide it for the exclusive use of chlorine.

BTW, if your cylinder develops that residue, a 3:1 water/muriatic acid solution will get rid of about 95% of it.

So how bad is my CYA and why would the pool store (with it's fancy machinery) say my CYA is 20?

Totally ordinary for Pool Stores to provide very, very bad test results.......trust your own testing.

 

[josephny]

Such wisdom on this board! Truly wonderful.

The idea of shocking with bleach on a Sunday evening and leaving only a tablet in the floater sounds great. Sounds like my questions as to whether I use regular Clorox Bleach and whether I can use that bleach with trichlor tabs simultaneously were both answered in the affirmative.

As for using the wrong tubes: Now that I know what tubes to use, I'll use the right one -- it was just the first time that I didn't notice the designated tubes.

I just retested CYA (see, I'll run out, but that's okay as I consider this, and the many, many other things I do as exciting learning experiences) and I'm pretty sure my cya is 60. I'll test again in the morning and hopefully get 60 again (or maybe less) and not test again until next week.

BTW, my swim season is mid-may through mid-september (sometimes end of Sept), with the help of a big-bottom heater and a wife that doesn't look at the propane bills (;-). Without the heater, my season would be early July through mid-August -- and it'd still be too chilly!

I think I read this in another post, but can't remember the answer: If I shock in the evening (8pm), will the pool be swimmable the next morning (10am)? That is, is 14 hours enough to wait after shocking a pool with Clorox when there's a substantial amount of stabilizer in it (like CYA of 60)?

Thanks,

Joseph

 

[Butterfly]

I think I read this in another post, but can't remember the answer: If I shock in the evening (8pm), will the pool be swimmable the next morning (10am)? That is, is 14 hours enough to wait after shocking a pool with Clorox when there's a substantial amount of stabilizer in it (like CYA of 60)?

At my house, our personal rule of thumb is that anything below shock level for your CYA level and at or above the minimum level is safe.

 

[PaulR]

In a clean pool the FC is supposed to hold overnight (drop at most 1ppm), so if you shock in the evening you should hope it would still be at shock level the next morning. If not you have gunk in your pool.

Post back how the shock+tab idea works, I am equally prepared to be brilliant or a dunce.
--paulr

 

[josephny]

Getting Started W/Bleach

Topics Merged for consistency

Here's the recent history:

On Sunday evening FC was 4.5 (ph 7.5, CYA around 60, temp 85). I added about 128oz of bleach. I also put 2 trichlor tabs in a floatie under a solar blanket.

Thursday evening (4 days later), fc was 3.5. I then added 160oz of bleach).

Friday morning (12 hours later), FC is 6. I also (think) I detected a little CC -- after adding 5 drops of R-0003, there was a ever so slight pink tint. 1 drop of 8071 turned it clear again. I suppose means I have less than .25 CC, right?

There's been a tremendous amount of rain over the past couple of weeks -- so much so that the pool water is overflowing, compared the the normal height of about 4-5 inches below the top.

I'm trying to figure out the system -- rate of loss, for example.

Am I right in concluding that I'm losing FC quickly for a CYA of 60?

Thanks,

Joseph

 

[frustratedpoolmom]

Re: Getting Started W/Bleach

That was a pretty significant drop between thursday evening and Friday. But with all that rain it's too hard to determine "normal".

If you can perform an Overnight FC Loss Test, when it's not raining, that will determine if there is something else going on.

One thing to keep in mind is if your FC is dropping below 5 (twice here you documented less than 5) it can allow algae to take hold. And it can take old before you see visible evidence of it - it's called "nascent algae" and you'll see in increase in your chlorine demand before you see green. You NEVER want the FC to drop below your min for your CYA level.

Once you figure out what's happening and are back to a "normal" routine, make sure you are adding enough bleach each night to prevent the FC from going below 5. So if you are targeting 7, and going below 5, target 8 for awhile and see if that keeps you above the min. Hope that makes sense.

 

[PaulR]

Re: Getting Started W/Bleach

Once you figure out what's happening and are back to a "normal" routine, make sure you are adding enough bleach each night to prevent the FC from going below 5.

This is the guy who only visits his pool on weekends, the normal routine is going to take a while to establish. Shock cover and floatie when he leaves, see where things lie when he gets back; I think this is only the first attempt.

One thing to keep in mind is if your FC is dropping below 5 (twice here you documented less than 5) it can allow algae to take hold. And it can take old before you see visible evidence of it - it's called "nascent algae" and you'll see in increase in your chlorine demand before you see green. You NEVER want the FC to drop below your min for your CYA level.

That is the trick.

Going from 9 to 3.5 in four days is more than I would have expected with a cover and two tabs. You probably do have some nascent algae and need to shock this weekend. Maybe shoot a little higher on Sunday when you leave, too.
--paulr

 

[frustratedpoolmom]

Thanks for pointing that out Paul.

Okay I merged the topics so that there is no confusion.

In the future, I would suggest you raise your FC higher before you go away, to ensure the FC stays up above the min. That Sunday dose was only enough to raise it up 4ppm... not enough for a 4 day absensce, even with a cover and tabs. Raise it up to 10 or 12 or all the way up to shock level would be better IMHO. If you come back with it slightly elevated, so what, you can still swim and you don't have to add bleach as soon as you arrive. Gives you more of a cushion.

You need to determine if the FC is holding overnight, and get this straightened out, possibly shock.

It make take a few trial and error issues like this before you figure out what works.

 

[josephny]

Sorry about starting a new thread when I should have continued the old one: I see it's easy to lose the history on a new thread.

I just started (a week ago) using Clorox bleach, so I'm gun-shy.

Thanks very much for the clear statement on keeping FC at or above minimum for my CYA. I'm also gun-shy on that, considering all the testers, strips, pails of tablets, etc. say don't swim in FC > 3 (some say 4).

But, tonight I will test and add bleach to raise to 8 (about 64 oz, as per poolcalculator, if I'm still at 6).

I'll shock it Sunday night and test CYA again (still not 100% confident in my reading).

Thanks!