Clear, but no chlorine???

[BigDave]

As long as it has pool water flowing through it, I wouldn't worry about it.

[mary jo]

So continue to keep the pool at shock level- 30- and see what happens to the CC.

btw: the skimmers again have a very thin line of sticky, greasy, black stuff around the waterline. I was going to wet a cloth with chlorine and wipe. Never had this before last Sunday.

[BigDave]

The shock seems to be working, I wouldn't stop now. Like PoolDoc said - clean that goo off while you can.

[Watermom]

Might try using a paste of baking soda and water to scrub it with.

[JimK]

So continue to keep the pool at shock level- 30- and see what happens to the CC.

btw: the skimmers again have a very thin line of sticky, greasy, black stuff around the waterline. I was going to wet a cloth with chlorine and wipe. Never had this before last Sunday.

I occasionally get the same black goo in the skimmers. I just clean it off when I notice it. It's been happening for years, but I've never notice a negative impact on the pool from it.

[mary jo]

A big thank you to FormerBromineUser- yesterday I got a "house call" from her to look at my pool - an extra pair of eyes might help. Everything that could be cleaned was cleaned EXCEPT----when I turned the in-line chlorinator OFF several weeks ago, I forgot to take the pucks out! Luckily FBU caught this and the petrified pucks (about 6 of them) were removed and the empty tower cleaned (with hose water). There was a rust-colored looking stain on the tower walls, a bit of sediment on the bottom, so I soaked it w/ hose water and sprayed it out w/ the hose on jet spray setting. It does look much cleaner and water in it is clear, so I turned it on just a bit to let water trickle thru it- there's no shut off value for the chlorinator and Nature2 unit (which are located next to each other on their own line).
Not sure if that was a contributing factor, but it's now empty and clean.

Numbers:
Yesterday FC went from 30 to 27 (dawn to late afternoon) so I added about 1/2 jug of bleach.

Last night tested @ 8:30pm FC=30 CC=2.0
This morning tested @ 7:15am FC=29 CC=2.5

I didn't get to the brushing yesterday- will do it today.

[BigDave]

Sounds good, 0.5ppm is the error in the test so those readings are pretty much the same. Have you had any sun?
I'd like to try a little experiment If you'll indulge me. For the next FC/CC test, use two dippers of DPD powder. Post any observation you have about the test.

[mary jo]

Yes, we had lots of sun yesterday, and today as well (so far). Should I do the 2 scoops when I test this afternoon or wait until this evening?

Also, a question: my husband is coming back in town and has already asked me if he can swim tonight. I now know (and now he knows) it's safe to swim @ FC30, but will it mess up the FC/CC levels if he does? I'd rather wait until we're in the clear- POP, right- but wanted your opinion on whether this would set us back any.

[BigDave]

Go ahead and swim - in an old suit. Next time you test, I'm curious if you'll see a difference at 30ppm FC.

[FormerBromineUser]

Just sterilize the hubby before he jumps in! ;)

[mary jo]

It rained last night, so hubby is going in the pool this morning (after playing tennis). I'll suggest he rinse off beforehand.

OK- BigDave- I must admit when you mentioned experimenting with 2 scoops of DPD my first thought was: hmm, you are testing for possible user error, which, given my # of rookie mistakes I'd say makes sense… but it turns out i DID get different results.

Yesterday's testing (8-28) The pool's numbers @ opening: FC=29 CC=2.5 Brushed the pool.

I ran FC/CC tests @ 4:00pm, 10ml sample, added my standard "1 heaping scoop" (because heaping is my standard), and got: FC= 25. CC=3.0

Same test w/ 2 scoops: FC=27. CC= 2.5
Then I tried 3 scoops: FC=31. CC=2
THEN I tried 1/2 scoop: sample "flashed" pink and then went clear again.

Hmmm- added a jug of bleach to the pool and waited several hours.....

Yesterday evening @ 8:30pm I tested using 1 and 2 scoops to see what would happen:
1 scoop: FC =30. CC=3.0
2 scoops: FC=32. CC=2.5
Did 2 scoops again: FC=32. CC= 2.5

This morning- tested @ 7am:
1 scoop FC=30 CC=2.5
2 scoops FC=32 CC=2

what's going on- or am I just an erratic tester?

also: just tested TA and pH: pH off the chart (but you mentioned this would happen w/ high FC), but
TA went from green to blue to pale yellow (after 14 drops). ???

[PoolDoc]

THIS is normal random variation in test results.

Same test w/ 2 scoops: FC=27. CC= 2.5
Then I tried 3 scoops: FC=31. CC=2



HIGH chlorine bleaches out low levels of DPD; this is ALSO a typical result.

THEN I tried 1/2 scoop: sample "flashed" pink and then went clear again.


THESE are also normal random variation in test results; statistically speaking, they are identical results.


Yesterday evening @ 8:30pm
1 scoop: FC =30. CC=3.0
2 scoops: FC=32. CC=2.5
Did 2 scoops again: FC=32. CC= 2.5

This morning- tested @ 7am:
1 scoop FC=30 CC=2.5
2 scoops FC=32 CC=2

[mary jo]

OK - good to know. I will continue on using 1 heaping scoop.
what about the yellow TA reading?

btw: hubby swam in the pool this morning- no skin or eye issues. sides and bottom squeaky clean. he said when you are actually in the water it does smell like a hotel pool.

[BigDave]

Erratic tester, nope, your results are consistent. The second scoop can make the endpoint more clearly defined and at the comparatively high chlorine level you have, I wanted to see if insufficient DPD might be influencing the test. Apparently it is. I think it's best to maintain the shock level a bit longer as yesterday's chlorine loss was about 5ppm and (by any measure) the pool still has significant CC. Can you supply of DPD powder survive 2-scoop testing? Morning and evening is plenty often enough testing now.

[Watermom]

Dave, did you see Ben's post above?

[BigDave]

@Watermom: No I hadn't, thanks for pointing it out - more simul-post.

I stand by my assertion that this is a case where our regular advice of one scoop is enough may be breaking down.

While the sample is too small for statistical scrutiny, mary jo's results are consistent and exceed the error of the test. 2ppm (4 drops) more FC was measured in each session. It's also worth mention that the measured CC was consistently 0.5ppm lower although this is in the error of the test. I am hesitant to ascribe this variance to testing error or bias (despite mary jo's assertion of rookie status) as she has performed these tests more often in the last month than most of us will in a season and that, while not blinded to the test, she wasn't aware of the expected outcome.

I think this is important as we start to guide people to HiC2 operation. 30ppm FC is beyond the limit of the test and Taylor suggests adding more DPD powder to accomodate.

[BigDave]

... he said when you are actually in the water it does smell like a hotel pool.When swimmers are in a high chlorine pool, the chlorine will get to work on skin oils, lotions, swim suits, etc. and will produce that too-familiar smell directly on the swimmer.

[mary jo]

OK- one thing I have learned is to order extra testing supplies, so while I am going through my DPD at a rapid pace, I have already ordered another one (i love amazon prime) so 2 scoops is fine.

on a related note: i wanted to ask about the plastic testing vial (Taylor gives it a strange name…I was reviewing their testing vid's last night). Just noticed a film inside the vial (i typically rinse,shake, air dry). I used dish soap today to clean it. Is this OK? (no info on vial cleaning anywhere)...

[CarlD]

OK- one thing I have learned is to order extra testing supplies, so while I am going through my DPD at a rapid pace, I have already ordered another one (i love amazon prime) so 2 scoops is fine.

on a related note: i wanted to ask about the plastic testing vial (Taylor gives it a strange name…I was reviewing their testing vid's last night). Just noticed a film inside the vial (i typically rinse,shake, air dry). I used dish soap today to clean it. Is this OK? (no info on vial cleaning anywhere)...

Yeah, keeping extra reagent is wise.

That black stuff doesn't seem to affect anything.

[BigDave]

Rinse it until all the soap is gone.

[FormerBromineUser]

also: just tested TA and pH: pH off the chart (but you mentioned this would happen w/ high FC), but
TA went from green to blue to pale yellow (after 14 drops). ???


Did you dilute the pH sample? If so, what IS your pH?


I asked Mary Jo also to test her TA because her jets have been set to bubble on the surface since opening. (She has very strong flow from her jets and I had her reposition them). As far as I understand, yellow would be your endpoint for TA with high FC.

[mary jo]

OK- tested pH with diluted sample (5:1) and got 7.6 but how do you calculate correct pH from there?
Took TA reading again and went from green to blue to yellow w/ 14 drops=140.

[PoolDoc]

Don't even worry about the TA, till everything else is OK.

[FormerBromineUser]

I was just concerned because of the potential for aeration raising her pH with those jets hitting the surface. Seems like it's okay.

[PoolDoc]

Manage the pH; don't worry about the TA.

[Watermom]

When you use dilution to test pH, you test it as normal. In other words, you don't have to multiply the result by anything. Just read the test.

[FormerBromineUser]

Just to explain why I asked you to test TA and pH:

I hadn’t seen a pH test result on your thread for a while. After seeing your pool the other day, I got to thinking that MAYBE your pH had risen. There was a potential for the “raging waves” (as your kids call the jet action on the pool surface) to have aerated the water. Lots of splashing does it too :)

Aeration raises your pH. Chlorine loses effectiveness at high or low pH levels. IF your pH had risen due to aeration (and chlorine additions), then getting pH back in range would be VERY important. Does that make sense?

[mary jo]

Yes, that makes total sense to me. What's strange is that this entire year the pool's pH was constantly low- even with the "raging waves" going constantly 24/7 and lots of splashing kids in constantly. What doesn't make sense (and I'm not sure I need to know- but I guess I want to know now) is testing pH using diluted water and not having to compensate for dilution.

[FormerBromineUser]

Did you use distilled water? Next time you test pH, try it with 1:1 dilution instead of 5:1. The less dilution, the more accurate. If that doesn't work, go to 2:1.

I'm not sure many people (except chemists) understand how to compensate for dilution in a pH test.

[BigDave]

pH doesn't test how much of something is in the water but rather the relative acidity / alkalinity of the water. Distilled water has no acids or bases in the water so it has little effect on pH.
We use dilution for testing pH because high chlorine causes the pH test to read falsely high.
The limit for the Taylor pH test is 10ppm chlorine. In your water, I'd dilute 2 parts distilled to 1 part pool water, test that mix and call it a fair approximation of your pool's pH.

[mary jo]

Thanks for the pH explanation. I used 3:1 ratio because 2:1's results were difficult for me to read. At 3:1 dilution, pH =7.6

Yesterday: FC went from 32 (morning) to 29 (early evening), and CC stayed @ 2.0. So I added approx. 24 oz of bleach (I figured about 1/5 of a jug) to bring the FC back up. At 10:30pm FC=31 CC=2.0

This morning @ 6:30am FC=30 CC=2.0

I decided to use the 2 scoops of DPD. Glad FC is holding, but darned frustrated about CC not lowering. Rainy day here, but sun just came out. Can't think of anything else to clean!

[FormerBromineUser]

Filters cartridges? You didn't clean them because they were new but maybe now?

[CarlD]

Since your FC went, during the day, only from 32 to 29, I'm not seeing the point in adding still more bleach to get the CC down, which has dropped. You just need a sunny day or 2, I think.

[mary jo]

CarlD- I envy your optimism!
I actually had a question about the cartridges. So far I have been adding bleach to my pool by pouring it around the perimeter (slowly). I've never added any chemicals to the skimmers -was told not to by pool installers- I think because of the inline chlorinator being full of tricolor pucks. But the chlorinator has been emptied and cleaned out- as has the Nature2 vessel. (I just wiped both down again and they are clean. Water also flows through the empty vessel but I turned the chlorinator off so it gets just a trickle).

Does adding chemicals directly to the skimmer offer any benefits (i.e. getting full strength CL to the filters)? btw: filter pressure started at 10 and is only 11 1/2 now and very strong pressure.

[CarlD]

Personally, my favorite way to add it is to the return stream. The ONLY reason I don't like adding it through the skimmer is that sometimes the chlorine splashes onto the deck material and discolors it.

[FormerBromineUser]

...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/

Still want you to do this..... Can't hurt and can only help.

[mary jo]

I did read the post by Pool Doc about cleaning cartridges- saw a couple videos as well. I already have a set of hosed-off filters awaiting a TSP soak.
I am reluctant to clean the recently added cartridges because they were added right before I started shocking, and were new and clean and the pressure has risen very little since then. Plus, honestly, I am still leary of doing this by myself- so I'll want my husband to "help" (maybe he'll get really good at this and it becomes his job-ha), but his availability is limited. BUT i hear you- it's the only thing left to re-check, right?
That's why I mentioned that perhaps pouring bleach directly into the skimmer could maybe help. I read that it helps clean the sand in sand-based systems, but have never read anything about cartridges.

[FormerBromineUser]

I am reluctant to clean the recently added cartridges because they were added right before I started shocking, and were new and clean and the pressure has risen very little since then... BUT i hear you- it's the only thing left to re-check, right?

Your pool has undergone a lot since you started shocking. Get the hubby on the job! Just my recommendation.

[BigDave]

The filters have been exposed to high level chlorine the entire time they've been in service, I don't think adding bleach to the skimmer would make any difference. I know it's frustrating but I think some more patience and sun will get you there.

[mary jo]

So keep up the testing and add bleach as needed to maintain FC 30?
Btw: my husband just got out of the pool- he's been in it several times now during the past few weeks, and for the first time he noticed that the water had a bitter "taste" to it- whereas in the past- even this Friday, it did not. (Not that he regularly drinks pool water). Ever heard of this before?

[CarlD]

I've experienced it, but I don't know what it means. Generally, sour means acidic and bitter mean alkaline, but it's not necessarily caused by the pH. I suspect it's stuff the chlorine metabolized but hasn't yet been filtered out.

[FormerBromineUser]

Agreed. Sounds like CC. Ever taste hotel pool water???!!!

[mary jo]

He said the smell is definitely like hotel but not as strong today- meaning worse yesterday. But the "taste" he's never encountered before. I thought it might be the rain - we've had some last night and early morning and the cover was open. I'll tell him it's CC and see if he gets grossed out.

Btw: I want to take is opportunity to thank BigDave and FBU and Watermom and CarlD and of course PoolDoc ( whom I didn't immediately realize was "the Ben" who championed the site), and everyone else here who patiently read through my not-so-succinct posts and helped me get closer to the finish line. I've learned so much already- thank you!!!

[FormerBromineUser]

Hahaha. Just wait til he takes that gross, old Tri-Chlor to the haz-mat! I can't imagine it's due to the rain.... Your CC was lower last night and this morning. Let's see where you are tonight and tomorrow.

[mary jo]

FINALLY….numbers even a pessimist can appreciate:

Yesterday morning @ 6:30am: FC=30 CC=2.0
Yesterday evening @ 9:00pm: FC=28 CC=1.0 !!!!!!!

Needless to say I tested several (OK 4) times to make sure. yea!

This morning tested @ 7:00am: FC=27 CC=1.0

So could that bitter taste in the water have been an "extinction burst"- the microbe's last hurrah before kicking it??? (I know, probably not, but I like the imagery).
OH- Add more bleach today or wait and see??? It's a sunny Sunday here.

[CarlD]

Nope. Things are looking very, very good for you. Just wait. I wouldn't keep testing all day. Just wait till the sun is setting and test then. If CC is .5 or less, you are done! Then you have to let your FC keep coming down to your maintenance level.

[BigDave]

Looking good. I agree with CarlD, don't add bleach and see if the CC is 0.5ppm or less this evening. If it's not, bring it back up to 30ppm. CC measures a lot of different chemicals most of which smell, taste, and feel bad. The time it's taken to make progress in your pool suggests that you've had some of the more complex combined chlorines that are harder to break down.

[mary jo]

Well, yesterday evening FC=25, CC=1 (lost 2ppm all day, had 3 people in the pool).
Added 1 jug of bleach @ 8:00, tested @ 10:00 pm FC=30 CC=1

This morning tested @ 7:00am FC=28 CC=1

It's a cloudy, rainy Labor Day here.

[BigDave]

Sounds like progress to me. 3 people in the pool with no increase in CC. Shame about the weather - maybe it will get better this afternoon.

[mary jo]

It turned out the weather did get a bit sunny as the day went on. Hubby went in the pool again (at night): water felt squeaky clean (opposite of silky soft?),smell of CL but no bitter taste…still getting a slight black ring around the skimmer.

Yesterday: morning FC=28 went down to FC=26 by evening. CC=1 again.
I added a jug of bleach and re-tested at 11:00pm FC=31 CC=1

This morning: tested @ 7:00am FC=29.5 CC=1.0

any day now…….