Clear, but no chlorine???

[BigDave]

It may take more than 24 hours to meet the endpoint criteria - just to be clear.

[FormerBromineUser]

What BigDave said!!!! And do some research on the light issue. With no visible algae and high chlorine demand, it is worth considering. The demand is coming from somewhere... I was scared to death my first time. Afterwards I just laughed at myself because it was so easy. You can shut off the breaker if you're concerned about the electricity. Glad your Mom is better.

[FormerBromineUser]

Just an aside here and sorry for hijacking you, MaryJo. BUT you are the man, BigDave for working so hard during Ben's hiatus. He is so incredible and we all owe him SO much. Thanks from me. Again, my apologies, MaryJo!

[mary jo]

Just checking in. Last night (Sunday) at 9pm I added the jugs of chlorine to get FC to 30. This morning at 7:30 I tested (using diluted sample as you described- 5:1, results x6 and DPD reagent) and got FC=18. My FAS reagent comes in today so I can get more accurate results.
I just added 3 jugs to get the FC back up to 30. My question is: how often do I check during the day?

[BigDave]

Check as soon as the FAS-DPD reagent comes in.

[FormerBromineUser]

Then, as often as you can to keep it at shock level. (Ignore purple highlighting).

[mary jo]

My reagent came in yesterday, and I tested throughout the day- tried to estimate testing times so that FC level never got below 25. Last night @ 11:00 the FC=33. this morning at 7:30 it was 22. Should I add more in the evening so that there is at least a 30FC level in the morning?

[CarlD]

You don't need to test and adjust your FC more than 3x day--Morning, mid-day, and after the sun passes in the evening. Morning and evening are the two most important tests.

Do we know your CYA/stabilizer level? If it's 100ppm or more, you need to maintain an FC level of 25 or more until the algae is completely dead.

Remember to run your filter 24/7, vacuum to waste, and brush the pool daily until you've won the battle.

[BigDave]

@CarlD: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.

@mary jo:CarlD is right, three times during the day should be OK but I don't think you need to vac to waste since you can't see any algae.
Do you have CC readings for the FC tests last night and today?
I'd like to see the FC stay above 30 but we run the risk of bleaching the liner.
Please continue to measure FC and CC after the last dose in the eveing has had a chance to mix in and after the sun is down and again before the sun is on the pool and before adding more bleach.

[mary jo]

yes, last night (11:00pm) FC=33
this morning (7:30am) FC=22
I added 2 1/2 jugs of bleach.
will test again @ 12:30pm

[FormerBromineUser]

Any CC?

Great minds.....

[BigDave]

How about Combined Chlorine?

Thanks FormerBromineUser!

[mary jo]

The test sample was barely pink (after adding the 5 reagent drops), then one drop of R-0781 turned it water clear, so <= 0.5

[mary jo]

Just had another thought : it looks like rain here. Should I cover the pool if we do get rain? I've never had rain water in my pool before ( another big rule from the pool installers which I've always adhered to- always cover the pool when it rains.... Rainwater is bad).

[FormerBromineUser]

Please continue to measure FC and CC after the last dose in the evening has had a chance to mix in
Are you giving it an hour or so to circulate and then checking to make sure you hit 30FC?

[FormerBromineUser]

.
Huh???? I OPENED mine at 5-ish this morning so I could get the rain in my pool.

[mary jo]

Oh- I see. At night, dose the pool with bleach to get a FC of 30, wait an hour and THEN take another reading for the night. Sorry, my brain is slow.

[FormerBromineUser]

Yes! You need to make sure you've reached the target FC. Under shock conditions you don't want to make assumptions. (Once your demand is gone, you won't have to do this).

Have you checked your CYA lately? BigDave mentioned the possibility of some conversion of CYA and I don't have time to back track to see when you last checked it.

[mary jo]

Last week (august 11) my CYA tested at 150. I typically do the test 3 times and average. (since it's a more subjective test than most- i think). I have not added any hose water since last week, but I will test it again today.

[Watermom]

If you tested CYA on August 11, no need to do it again. Just wastes reagents.

[mary jo]

already tested everything at 12:30. CYA=150. FC=32, CC=0
however- pH is up to 7.8 today. it's been hovering around 7.6 for the past week.

[BigDave]

... Have you checked your CYA lately? BigDave mentioned the possibility of some conversion of CYA ... I think this may have happened before mary jo started this thread when the FC was 0 for alot of the time. I don't think it's an ongoing issue.

@mary jo: pH test is probably inaccurate with FC at this level, I wouldn't bother with it for now.

[JimK]

Just had another thought : it looks like rain here. Should I cover the pool if we do get rain? I've never had rain water in my pool before ( another big rule from the pool installers which I've always adhered to- always cover the pool when it rains.... Rainwater is bad).

I don't know there's anything inherently bad about rainwater. I've never noticed any negative effect. The only time it's an issue is if we get too much and I have to pump water out of the pool (may have to rebalance after that). Of course if we get a lot of wind as well then there the mess to clean up from all the crap from the trees (we have a lot of trees around).

[FormerBromineUser]

.
Was the 32 FC result at 12:30 BEFORE adding anything?

In other words, is this scenario correct:
7:30 you were at FC 22; you added 2-1/2 jugs
12:30 retested FC and got 32. No additions from 7:30 to 12:30

I just want to make sure about this because if this scenario IS correct..... your results are promising.

You only have to do the “wait an hour and retest” at night when you’re trying to determine overnight chlorine loss. I wanted to make sure you understood the AT NIGHT part.
At night, dose the pool with bleach to get a FC of 30, wait an hour and THEN take another reading for the night. Sorry, my brain is slow.

[FormerBromineUser]

Please don't bypass my above post but I am going to bring up a side issue which has been bugging me all day. I had questions about your pool installer before but now.... Rainwater is bad? He said that? The overwhelming majority of outdoor pools are not covered in the rain. If rain was that "bad" for a pool, many pool owners would be in big trouble. I LOVE rainwater as it keeps me from having to fill from my iron-laded well water. Was the "rainwater is bad" part of a sales pitch to get you to purchase an expensive auto-cover? You have the best reason in the world to have an auto-cover: your son. Don't get me wrong. I have an auto-cover and love it! However, in my book, rainwater is a blessing!
p.s. Did this same installer say anything that made you hesitant about cleaning behind your lights?

[mary jo]

Hi- I did look online yesterday and found some specific info on the possible negative effects of rainwater ( namely acid rain messing with the pH) . A chem geek guy gave a very detailed analysis about plausible scenarios - ie. what 1" of rain does to pH level.... required logarithm calls but results were negligible. I think the pool guy wanted to offer me the most maintenance free options and no rain water means less chance of algae and less vacuuming? ( and yes he did mention acid rain messing with the pool chemistry). Good to know I don't have to run out and close it all the time.

[BigDave]

Rain does usually drop my pH a bit, not usually enough to adjust. Big storms drop alot of leaves and sticks in my pool.

Did you get an overnight chlorine loss reading? What are the FC and CC measurments?

[mary jo]

Ok- this mornings stats:
Last evening tested at 7:45. FC =30 CC=0.5 added 1 jug
re-tested at 9:00. FC=36
Tested again at 12:45. FC= 36. CC=0.5

This morning tested at 8:00 CL=28. CC=1. Added 1 jug
re-tested at 9:00 CL=33. CC=1

[BigDave]

Sounds like it's going well. Lost 11ppm FC night before last and 8 last night. Good.

Is the pool still clear with no smell?

[mary jo]

The pool is still very clear, with no smell.
I didn't realize it was such a slow process….

[BigDave]

I am sorry about that. Expensive too. I know it's no consolation but it didn't get this way quickly either. The one pool tool that's as important as a K-2006 is POPP (Pool Owner Patience and Persistence).
Keep it up, it sounds like you are making headway. :)

[FormerBromineUser]

Can you even imagine how much MaryJo would have spent at the pool store so far had she not found the forum????

[mary jo]

I really do appreciate a "good process", which is why I am so grateful I found the forum when I did. Ironically I do not swim (or even like water) so the process is not messing with my patience at all- it's the husband and kids who are used to swimming every single day, morning noon and night who are!

So- last night's results continue to be good… I'm almost ready to be cautiously optimistic.
tested @ 11:00pm CL=36 CC=0.5
added 1/2 jug of bleach
re-tested @ 12:30am FC=36 CC=1

this morning tested @ 7:00 FC=33 CC=1

It has been raining on and off throughout the night- left the pool open b/c I was up most of the night anyway and had planned on filling it today with the hose. After about an inch of rain (which is what I needed to add), I closed the cover.

[CarlD]

Looks good. If the pool is clear, I'd watch it for a day to see that the FC doesn't drop much (it will drop some, especially during the day). You can try adding two drops of R-0007 to your sample before testing pH (R-0007 is the chlorine neutralizer you use with T/A testing) Get a rough idea of it.

[mary jo]

yes, I will continue to test and add bleach as needed. I tested pH today, and even with adding 2 drops of R-007, the pH was very high- 7.8 - 8.0 range.

[BigDave]

Super, sounds like the chlorine demand is subsiding. Keep it up - you're doing great.
Let's wait to finish the shock before moving the pH - some by-products of the shock are easier to live with when pH is on the high side.

[FormerBromineUser]

Agreed.

Only 3ppm loss last night. Good progress!

[mary jo]

yesterday evening's test results:
tested @ 10:15pm FC=34 CC=1.0

this morning tested@ 7:00am FC=33 CC=1.0

getting better…

i had a question about testing with diluted water: I am currently testing using 5:1 ratio (distilled/pool). Is this OK or would a smaller ratio ( i.e. 3:1) give me more accurate results?

[FormerBromineUser]

Hey, hey! Only 1ppm loss! Getting better!

As for diluting, they're your reagents and history has shown you aren't afraid to use them to excess ;) If you want more accuracy and don't mind using more reagent, I would suggest just doing it for the overnight testing.

Good job! You have learned a ton!

[BigDave]

I'm sorry if this should be obvious, but, for which tests are you using the dilution method?

[mary jo]

I've been using dilution testing for FC/CC and CYA.

[BigDave]

You are diluting the sample for the FAS-DPD test? If so, please don't dilute it more than 1:1. Yes, it will take alot of R-0871 - you might want to order a 2oz bottle. You are getting close to the end and I'm concerned that a 5:1 dilution might be skewing your measurments.

[CarlD]

Why would you use dilution for the FAS-DPD test (head scratch) ?

Merely fill to the 5ml line (or halfway to the 10ml line if you don't have a 5ml line) and count 1 drop = 1ppm of FC.

[BigDave]

@CarlD: I have a cylinder I use for testing that has a 5ml line (I suspect you do too) from a different kit. The K2006 comparator starts at 10ml.
@mary jo: Perhaps you have another vessel that can measure 5ml. The dose cups from children's medicine comes to mind.

[FormerBromineUser]

Not that I'm an expert, but... You can use the patented CarlD shot glass dilution method of chlorine testing to get a start this weekend. Mix 5 shot glasses of distilled water with one shot glass of pool water then test the mix for chlorine and multiply by 6. Not accurate enough to know when your done but good enough to start the shock process. You intended those instructions for the weekend only (when she was out of 0871).

Also, I believe she bought the 16oz bottle so she should be good even with the 10ml sample.

If not, Mary Jo, I still have an extra 2oz bottle of 0871 if you need it. I am leaving for VA Saturday morning so you would need to let me know today.

[mary jo]

Oh you must think I'm daft! Yes, FBU got it right: I misunderstood the weekend instructions (diluting at 5:1) to mean continue testing this way until almost done, and since I was going through 50-60+ drops at a time, testing 4-5x a day it made sense….until last night when it occurred to me the exact ppm's lost were getting more critical. That's why I asked about it this morning….I also have been testing each sample more than once to make sure I didn't mis-measure or mis-count.
Good thing I got the 16oz bottle!
From here out I will test at 1:1. I'll post results tomorrow.
I'm sorry about the confusion!

[BigDave]

I don't think you're daft at all. It's on me that I told you to dilute 5:1 and didn't correct that when you received the titrating reagent. I apologize.
The good news is that it appears that a lot of the chlorine demand has been met.
Get a good set of readings for overnight chlorine loss and let's figure out where to go from there.

[mary jo]

BigDave, you are too kind….and most likely a very patient person.

Well, today's results are good and bad I think:
tested last night using 5ml sample. 1 drop = 1ppm

tested @ 11:45pm FC=36 CC=3
tested this morning @ 7:00 FC=35 CC=3

The chlorine loss sounds good, right?
The CC reading of 3 doesn't sound good! (altho I suspect, ahem, it was always testing at around 3 since I failed to multiply the drops added for CC by 6 when I was using a diluted sample…. This one's definitely on me).

So I'm not sure if that changes anything in our approach to getting the pool back in sync.

[BigDave]

Good, keep the shock going. With the 5ml sample test the error is 1ppm so 3ppm is still significant. I don't recall if you have a cover but if you do, leave it open during the day.

[mary jo]

OK- overnight test results are not so good for some reason.
I decided to use the 10ml sample since I now have enough product.
tested last night @ 11:00 FC=35 CC=3

tested this morning @ 7:15 FC=30 CC=3

Is a hiccup like this common? I repeated this morning's test 3 times to be sure.