Clear, but no chlorine???

[CarlD]

Dropping from 33 to 30 overnight? Perfectly normal! when you are super-shocking it's harder to maintain the FC...and you only dropped 9%. I wouldn't worry about that at all.
What I'm wondering is why your CC is so high and not dropping with FC > 30.

PS: I'd run the FAS-DPD test using the 5ml line instead of the ten. If you don't have that line you can either guess where it is or use a kid's med cup that comes with cough medicine with a 5 ml line. Each drop then is 1 full ppm rather than .5. It will take less time to do the test, use half the R-0871, and certainly be accurate enough at those high FC levels.

[BigDave]

I pretty much agree with CarlD, the FC loss is not such a big deal but the CC consistent at 3ppm.
Two questions:
How much bleach did you use yesterday?
Is there any chance that a bromine product has been put in the pool.

[mary jo]

OK- it was actually a 5ppm drop (35 down to 30). Did I wait too long to take the morning test? (should I test before sunrise ~ 6:00?) Yesterday is was overcast and rainy all day. This morning it's sunny.

I added 1 1/2 jugs yesterday. Yesterday morning's initial reading was 35 so I didn't need to add much to keep it at 30. I added the last jug @ 9:00 and tested at 11:00 and got 35.

Not sure what bromine is, but the only chemicals ever put into my pool this season: pH up (about 15 lbs), phos-free (1.4L) and 3" chlorine tablets for the inline chlorinator.

[CarlD]

It's still not a big change--if it dropped from 35 to 20 or 15 we'd be concerned, but from 35 to 30? That's OK.

Bromine is an alternate sanitizer to chlorine. It's more expensive, has a number of drawbacks, but is much more resistant to heat in hot tubs. It also doesn't "play well" with chlorine.

pH Up! is nothing more than Sodium Carbonate, aka Washing Soda, just overpriced.
3" chlorine tablets are Tri-chlor tablets--if they are 99% they are good. But for every 10ppm of chlorine they add, they add 6ppm of CYA/Stabilizer, plus push pH down.
Not sure what's in the Phos-Free, but I doubt there's any bromine in it.

Combined Chloramines can be all sorts of chloramines, not just the one bromine mixed with chlorine produces (monchloramine?) All kinds of things can be metabolized to form them, but guessing which one(s) caused the CC=3 is beyond me.

[BigDave]

1-1/2 jugs of 8.25% in 15,000 gallons is a daily chlorine demand of about 8ppm which still seems high to me.
I asked about bromine because bromine can create a permanently high chlorine demand.
I will put together another summary of this thread later today and ask PoolDoc or Richard to take a look.

For now, I'd maintain shock.

[PoolDoc]

Just checking in on this thread; obviously some good progress has been made.

But I have a couple of suggestions.

1. Unless you know of some reason not to do so, remove the Nature2 cartridge, even though it's old. ANY cartridge or filter media is a potential reservoir of accumulated oxidizable 'goo'.

2. For the same reason, clean the filter cartridges. Be sure to do it correctly. Spraying them off (with the hose; NOT with a pressure washer!!) is a good intermediate cleaning, but a full cleaning, which should remove any oxidizable 'goo' that could create chlorine demand takes more. See http://pool9.net/cart-clean/

3. It wasn't clear to me whether you ever inspected light niches or other recessed or hidden areas in the pool. If there are any such recesses, and if it's at all possible, inspect them. It does happen that such locations will fill completely with live 'slime'. Physical cleaning is required; otherwise, the slime will just 'recover' when chlorine levels drop.

Good luck!

[mary jo]

WOW- just checking in to ask about the Nature2 and cleaning the light niche…
to reply to your suggestions:
1. Nature2 cartridge: to be clear- remove old cartridge and clean the empty vessel? No way to remove the whole unit huh?
2. New Pentair filters installed a few weeks ago. Initial pressure set at 10, it is now 12. Strainer basket is clean and no debris.
3. My husband is home for the day: Should he clean the niches today or wait and see for a few more days? Don't think there are any other hidden areas: built-in ladder, built-in stairs, skimmers look clean, never much in them at all.
is there a youtube vid that shows the process of cleaning a niche (besides turning off the circuit breakers)!

I also took a look in the auto pool cover "pit". Removed the incredibly heavy concrete cover pads to find just a little wet/dry debris (mostly leaf pods). No funky smell or dead animals... The pit only goes down about 8" before you hit gravel backfill. Poured and wiped the cover with diluted bleach water as is was rolling up and unrolling.

the lawn guys were here and i closes the cover to see if any grass/debris was getting onto the cover. I don't think it is: the pool's elevation is much higher than the grass area: 5' drop on one end (foundation wall) and 45 degree slope to grass on the other.


btw: How do you remove and clean the lights when the FC is 35? You can't safely go into the pool at that level, right?

[PoolDoc]

35 ppm is not dangerous to people at all. With a CYA level = 150 ppm, 35 ppm FC is LESS aggressive than pool water that has 1 ppm FC and no CYA! (There is a difference -- 1 ppm FC will be used up rapidly by swimmers in the water; 35 pp will not. The 'extra' held by the CYA will continuously replace the 'active' chlorine as it gets used up).

But, it *may* be 'dangerous' to some swim suits, so wear an old one. It will also be somewhat irritating to your eyes, but, when trying to open the light niche, it would be best to use goggles or a mask regardless of chlorine level. In most cases, there's a single screw that needs to be removed to allow the light niche to 'flop' out.

This video, from Inyo pools, comes closest to showing what's involved. Obviously, you don't need to focus on the bits about actually replacing the bulb or lamp.

[mary jo]

OK- watched the video. Seems like it's something I need to do. I'm assuming that any slime or goo I find will have a color? Meaning that if the niche is not covered with visible goo, than I just need to wipe it down and re-assemble?
Good to know that high FC levels won't melt your skin off or anything. I've got an active imagination where chemicals are involved….

[mary jo]

Yesterday @ 5:00 pm my husband cleaned the light niches: One niche and light fixture perfectly clean. The other had a very small amount of brown stuff in niche and on fixture- wiped w/ a white cloth, let everything soak for 20 minutes before my husband had to leave town. I then scrubbed the skimmers again. Don't know if it's important but for first time ever I noticed a thin ring of solid black at the very top of the water line in both skimmers. It looks and feels like black grease, but wiped off w/ chlorine and cloth. hope this does something…anything else to clean or check?

overnight numbers:
last night - tested @10:00pm FC=33 CC=3
this morning - tested @7:00 FC=33 CC=3

[BigDave]

How much bleach did you use yesterday?

[mary jo]

one jug in the morning, and about 1/3 jug that i poured into the skimmers when wiping them down again.

[PoolDoc]

Commonly, a black line around the pool water line (and the inside of the skimmer) is a combo of people goo and lotion. At pools where many of the users are what my employees used to call "slip & dippers" (slop on the oil till they were slippery, then rinse it off in the pool, then repeat) the accumulation could be heavy.

I've also seen it occur when trichlor tabs with unusually high amounts of silicone mold release (from the process that presses trichlor powder into tabs) compound were used.

Regardless, you DEFINITELY want to clean it off if you can; time + sunlight + chlorine tend to make the black mark permanent.

[mary jo]

That certainly makes sense. What I find odd (and why I mentioned it) is the timing…I've been shocking my pool for a solid week now (to 30-35 FC), with nothing/no one in the pool during this time (other than my arm to retrieve water samples) so why would a black ring of goo suddenly show up on Sunday morning? I check and empty my skimmer/baskets daily and Saturday there was no line at all.

I've had dozens of (mostly) girls in the pool with very health-conscious mom's who indeed slather and spray them right before they swim…even tho I tell them repeatedly it's just going to come off in the water. I've never had anything black before. Is it the high FC levels "leeching" stuff out?

[BigDave]

@PoolDoc, I don't know if you've read through this whole thread, so here's my quick summary from post #59:
mary jo's pool has CYA of about 150ppm, CH of 750, a history of trichlor use, periods of zero measurable chlorine, and low pH. There's no visible algae, and high chlorine demand. The Nature 2 cartridge is in place but hasn't been replaced in the last two years. There is a possibility that some amount of fertilizer made it into the pool. My guesses are that some CYA may have been converted to ammonia causing chlorine demand (no bad smell so probably not); the fertilizer may be causing chlorine demand directly; or that a nascent algae bloom (possibly aided by fertilizer) is causing chlorine demand.

Since I wrote the summary, the pool has been brought and kept at 30ppm FC and has been there for some time. During the shock, the chlorine demand seems to be subsiding but still about 7-8ppm /day with a consistent 3ppm CC.

Thanks for looking in.

[mary jo]

btw: just tested again @ 12:30 FC=30 CC=2.0
should I add a jug of bleach or wait and test later this afternoon?

[CarlD]

With an FC of 30 I'd hold off on adding more chlorine.

[PoolDoc]

I've had dozens of (mostly) girls in the pool with very health-conscious mom's who indeed slather and spray them right before they swim…even tho I tell them repeatedly it's just going to come off in the water. I've never had anything black before. Is it the high FC levels "leeching" stuff out?

Dozens of girls, heavily coated with suntan goo, would DEFINITELY create a higher than expected chlorine load on a small home pool.

@BigDave: Any remaining ammonia would show up as CC's. Ammonia reacts VERY quickly with chlorine, so it's not likely that that is still an issue, though it may have been one before.

On the other hand, most IN-GROUND pools are very lightly used. An IG pool with lots of coated girls will have a chlorine demand that is a MULTIPLE of the typical of the 1 - 2 ppm per day.

@mary jo: If you have more than 1 - 2 girls at the pool at one time, and they stay longer than 1 hour at a time at the pool, there's a high chance they are peeing in the pool, too. If any of them are competiive swimmers, that chance approaches 100%: virtually all USS (year round) swimmers, middle school and up, routinely pee in the pool.

This is not a health risk -- urine is normally sterile -- and on well chlorinated outdoor pools exposed to full sun, it's not even a chemical problem, because chlorine + UV quickly break down the chemicals in urine. But it WILL produce a major increase in chlorine usage.

[BigDave]

@PoolDoc: mary jo hosted a pool party before starting the shock and has had no swimmers since - sorry, I should have included that in the summary. I agree that any ammonia would show as much higher CC and smell. After over a week at 20% shock level with clear water I doubt it's algae. So... maybe the fertilizer? Maybe space aliens? Any other ideas or more importantly, course of action? Thanks again.

[mary jo]

OK- off track here but have to comment: the pee in the pool thing really grosses me out. I may have to initiate a mandatory "pee before you get in" rule (right after the "don't splash mom" rule). I already have strict rule about always, ALWAYS having a dedicated adult watching any junior swimmers in my pool. If I'm spoiling their social scene then too bad, kiddo. I heard about the public pool stats but seriously- in a private pool people do this???

[CarlD]

Grosses me out, too!

My dad (RIP) used to have two signs on his pool:

"We don't swim in your toilet. Please don't pee in our pool!"

and

"This is our OOL. Notice there is no 'P' in it!"

[FormerBromineUser]

Always with the folksy asides, Carl, love it!

While awaiting your morning numbers, I have a silly question. You have mentioned vacuuming but I don't think you've ever mentioned brushing the sides. May I assume you are doing that? I am just trying to think of anything and everything!

[CarlD]

Always with the folksy asides, Carl, love it!

Uh-oh! Am I in trouble again?

[mary jo]

So CarlD- think they still make those signs? (altho my very understated husband would freak if I put a sign up).

What trumps pee in the pool? Finding a dead critter, maybe. This morning I found a dead vole (I'm guessing) in the skimmer, gave a shriek, all the kids came running out and took pictures for instagram. "cool mom!"

Well, yesterday's FC numbers stayed constant all day w/ FC=30. CC went up and down (3 to 2 to 2.5 yo 3).

Yesterday evening @8:15 FC=30 CC=3 first time ever the cup of test water smelled like heavy chlorine….it was overcast all day.
This morning tested @ 7:00 FC=30 (one test read 31- not sure how that is possible), and CC=2

oh-FBU: yes I brush the sides, feel them often for slickness. also have the kids and hubby do this while they are in the pool, but I haven't vacuumed since I started the shocking process. Is this something I should do now?

[BigDave]

Only need to vacuum if there's stuff to clean up. You should, however, brush floor and walls. How much bleach did you use yesterday?

[mary jo]

I didn't add any bleach yesterday. The FC was 33 at 7am and went down to 30 in the afternoon and and stayed @ 30 all night.

[BigDave]

It's good to hear that the chlorine demand has subsided. Now to get a few sunny days to clear the CC.

[mary jo]

OK- so, as long as the pool is holding chlorine, the sunlight will lower the CC level? Sunlight lowers CC?

We are on the cusp of a severe thunderstorm with high winds, hail etc. No sun today unfortunately.

I should continue testing, right? If FC is at 30 now, at what number should I add more bleach?

[BigDave]

Chlorine and sunlight sould work together to clear CC. But remember, we still don't know what caused the chlorine demand and the CC in the first place, so we're following a general rule and not working to remove a known contaminant.
Yep, keep testing in the evening and morning - doesn't sound like there's any reason to test more often than that. Since each jug adds about 5ppm FC to your pool, add another jug when the FC gets to 28-30ppm.

[Watermom]

What trumps pee in the pool? Finding a dead critter, maybe.
How about finding a dead body in your pool! That's what trumps both pee and dead critters. A few years ago, one of the former moderators found that her neighbor had committed suicide in her pool.

Makes a little pee seem insignificant, doesn't it?

[BigDave]

Watermom wins. I never want to hear about anything worse. I don't remember that, was it posted on the forum or, hopefully, privately discussd?

[JimK]

How about finding a dead body in your pool! That's what trumps both pee and dead critters. A few years ago, one of the former moderators found that her neighbor had committed suicide in her pool.

Makes a little pee seem insignificant, doesn't it?

Yikes! :eek: ....I think I'll stop complaining about spiders in the pool.

[Watermom]

She told us privately and then much later it was mentioned on the forum as well. It happened a long time ago, Dave, before you joined the forum. Talk about an awful nightmare to have to deal with!

[CarlD]

I don't remember it. Was it even before MY time, Lisa?

[CarlD]

Yikes! :eek: ....I think I'll stop complaining about spiders in the pool.

And most of us are unhappy when our neighbor's trees dump stuff in our pool.
Dumping bodies in your pool is REALLY the sign of a bad neighbor!

[FormerBromineUser]

Didn't really want to be reminded of that.... What a nightmare. :sad:

I much prefer the plastic toy snake that appears "coiled and ready to strike" in my skimmer occasionally. Don't know how it gets there...

[CarlD]

Ha! Ask your kids or your "significant other"! (Of course, they'll all answer "Not Me!")

[PoolDoc]

About Pee in Pools:
Basically, any kids who were hydrated when the left in the house, and who remain in the pool 2 hours (where they aren't sweating) have probably pee-ed in the pool.

Dedicated US Swimming participants (year round swimmers) pick up the habit of doing so during 2 hour practices during which they aren't allowed to leave the pool. (Coaches HATE having to retrieve swimmers who are tired and taking an extended break in the rest room.)

I know it's gross -- till you get mentally adjusted to it. Urine is normally sterile, which is why doctors can test for bladder infections using a simple presence/absence test for bacteria. Consequently, it's not really a health problem. But urine DOES use up quite a bit of chlorine, and it combines rather badly with chlorine at that. On outdoor pools exposed to solar UV, the combination of chlorine + UV destroys the byproducts rapidly. The one place where pool UV systems have a REAL value is on indoor pools where these combination products accumulate in the absence of solar UV.

But, if you want to keep pee out of your pool, you either have limit pool sessions to 1 hour or less OR provide an EASY alternative. Many homeowners exclude dripping kids from the house: if you do, you also have a pee-filled pool, unless you've worked out an alternative. This can be -- depending on your fences and family's modesty standards -- as simple as a designated pee-bush! Others set up a camping type portable outhouse. Of course a dedicated pool house with a flush toilet is the ultimate solution, but you'll need an extra $20,000 or so, plus enough yard, if you want to take that route.

About Mystery Chlorine Loss:
The most common identified causes of 'mystery' chlorine loss include:

1. Unrecognized algae or bacterial growth, like mustard algae deposits or water mold (in light fixtures, etc)

2. Prior use of a bromide product for mustard algae, or just about any product made by United Chemicals

3. Low CYA, due to an earlier algae / biofilm bloom.

4. Unrecognized heavy bather 'load', such as REALLY oily swimmers, or swimmers with full bladders.

5. Regular use of algaecides.


Fertilizer will not affect chlorine use EXCEPT by helping to fuel algae or bacterial growth, as in #1 above.

[CarlD]

My next-door neighbor has a summer "pool bathroom" that's outdoors, sort of, but built into the house. They have to winterize it, of course, shutting off the water and filling it with pool anti-freeze every fall. No idea what it cost.
We don't but in an emergency it's just steps across a tile floor to bathroom off the kitchen--and it's a rough tile we put deliberately put in because it isn't deadly when wet.
Plus, after an hour, we get kids out.

[mary jo]

@watermom- Indeed a dead body is the ultimate ick factor. Sure took my mind off of pee in the pool…

so today's stats:
Yesterday pool stayed at FC30 most of the day, dipping down to FC29 that evening.
I added 1/2 jug of bleach and re-tested @10:00pm FC=31 CC=2.5

This morning tested @ 7:15 FC=30 CC=2.0

I'm not sure what else to clean! I fear we are approaching the end of the flow chart, and the dreaded "d" work (drain) is coming up….

[FormerBromineUser]

.
NO! Don't be discouraged.

FC numbers are looking good, especially with the very sunny morning today and taking the measurements at 7:15. Your CC is down to 2 so it is showing progress... albeit slow... but maybe you found the culprit in the light niches, filters, Nature2, or somewhere.

Hang in there! Besides, you have a vinyl liner so "draining" is not a realistic option.

[BigDave]

I'm not about to suggest that you drain. It looks like you are down to normal chlorine usage rates and the CC seems to be creeping down in spite of the cloudy skies.

FormerBromineUser's post reminded me: You did remove the Nature 2 cartridge, yes?

[mary jo]

It turns out the pool guys removed the cartridge- either at last year's closing or this year's opening. The vessel is empty and clean.

OK- I wanted to add one more thing: my husband- who loves water but is pool illiterate- noticed "an extra hole" in the side of the pool while he was cleaning the light fixtures. I told him it was a dedicated return jet that the pool installer added assuming that we were going to go with the Legend's automatic vacuum system (an extra $1000). So the return jet was never used. Is this something that needs to be cleaned/maintained? I didn't think so since the other returns don't, but wanted to mention it just in case. I'm going to brush everything down today.

[BigDave]

That extra return line is a place where "stuff" can grow and hide. is the other end of that line connected to anything or just capped off?

[mary jo]

It must be connected because water comes out of it constantly- however, the pressure is lower than the other returns. It doesn't have a directional attachment on it- literally a 3" threaded opening.

[FormerBromineUser]

Can you reduce the flow to your returns and increase the flow at this extra line? If so, do it for an hour or so to really force the shock level water in there. You would do the same thing for other water features: fountains, slides, etc. periodically, and especially at high CL levels.

[mary jo]

Absolutely don't know how to do that!

[FormerBromineUser]

Is there a valve for the "extra" line? If so, we can tell you how.

[mary jo]

i was never told about an extra valve- was told not to worry about the extra hole…..I have 3 "T" valves. I turn off 2 when vacuuming.
(I probably need to review pool terminology)

[FormerBromineUser]

When vacuuming, you leave on the skimmer valve. You apparently close the main drain. What changes when you close the third one?