a few shocking questions

[tltmom]

opened and started shock 5 days ago.
I test the water with last season's tfp-100(stored appropriately over winter). new kit on the way.
I followed tfp directions.
The pool has cleared from murky turquoise to sparkling clear. Never saw any visible algae

I tested the CYA 5 days ago, when the weather was pretty cloudy. I got 35-40. Today was super sunny, so I retested. I let the water sample warm up too. I got 25 several times.
So it turns out I have been putting too much LQ Cl in my pool.

I've done an overnight test a few times since the water looks so good. I lost 4, then 3 then 2 ppm over the last 3 nights. So I guess I'm getting close.

My questions:
-should I back off a little on the Cl now that I know my cya is lower?
-should i add some cya now or wait until I'm done shocking?
-is it at all surprising that I have something growing in the pool even though I basically did a mustard algae treatment? Seems like I should have killed it already but maybe I need P.O.P.

Thank you

 

[JasonLion]

You might as well lower the shock levels based on a CYA reading of 30. That gives you a little margin and is still lower than where you were before.

CYA around 25 is fine for shocking. Leave it alone until you are done shocking.

Shocking can go different ways. Have some smallish chlorine loss towards the end of the process isn't the most likely outcome but it is common enough. You almost have it, annother day or three will do it, so get out a six pack of POP and relax.

 

[tltmom]

Hi
a few follow up questions...
I think I'm done shocking. pool lost 1ppm last night, cc=.5, water looks fantastic.
I actually kept shock level up today just to be absolutely sure, because I didn't shock quite long enough last spring and had some trouble after that.
here are my current numbers:
fc 9.0
cc .5
CYA 25
pH 7.2
TA 90
salt (swg readout) 2950
didn't test CH, I'll fix that next week.
water temp 69

It's really sunny, so my Cl is getting eaten up really quickly due to low CYA
I was planning on adding 4#, then another 2-3 to bring it up.

My concern is this: according to the pool calculator, adding CYA will bring the pH down by .3
Is this a concern? the ph would get pretty low. I was thinking of starting my swg now to bring the pH up, then add the cya. does that sound like a good idea? or am I overthinking? wouldn't be the first time!

 

[jblizzle]

The CYA takes a few days to dissolve, likely the reduction in pH may not even be noticeable, but the SWG could be used as you describe.

I would imagine that you will be firing up the SWG in the next few days anyway right?

 

[tltmom]

I was planning on starting up the swg soon now that the water has warmed up.
I just put in a new ic60 so I'm pretty interested in starting it and seeing how it does.

Thanks for your input!

 

[tltmom]

well, I'm stumped so I thought I'd check in

after completing the shock process (all 3 requirements) I let the Cl come back down below 10. Quite a bit of tree debris and pollen is out here, so I kept the Cl between 6-10 to make sure I don't dip below minimum.

It's been cloudy, cool (60's) and rainy here, so I wouldn't expect to have a lot of Cl loss to the sun

My problem is this:
I think the pool is losing an excessive amount of Cl. I'm concerned that I didn't quite finish shocking the pool. I have some trouble with getting really consistent results on fas dpd so maybe I did not really pass oclt(?) the other day. i read the extended directions yesterday and my results have gotten more consistent.

test results:
5/5 am pm
FC 10.0. 6.0
cc .5. .5
CYA. 30ish
pH. 7.6
rest not tested

there was a loss of 4 ppm which seems kinda excessive for a clean pool with cool water, cloudy weather.
as best I can tell, OCLT .5-1 over the past few nights.

Probably not the best idea, but I thought I'd try MA shock, so I kept the pool at that level yesterday, lost 1ppm overnight last night. I vaccuumed the pool yesterday, but I can't get the light niches out to check behind them.

I can't tell if there's an issue or not. last spring I thought I was done shocking and then had another algae outbreak as soon as the weather warmed up, so I'm trying to avoid that.
aso, I'd really like to finish tuning up this pool (Ch, Cya etc)

how long can I use MA levels, and do you even think it's neccessary? I don't want to harm the equipment

I have done so much reading on this great website, but apparently my pool has not! It does not seem to "behave" like the other pools I read about here.

 

[duraleigh]

You will not harm anything shocking at the suggested MA rate. It is suggested because it is safe.

I agree that your FC consumption seems just a bit excessive. I would up the CYA to a solid 40 ppm and, as long as your water is crystal clear, keep the chlorine at about 8-10 ppm for a few days and then redo the OCLT. That should get rid of any remaining organics in your pool.

I see no real reason to elevate the FC to MA shock but it is harmless enough if you choose to do it.

 

[tltmom]

Thanks, duraleigh.
Just in case folks are following this thread, I thought I'd update. I always appreciate when people add a lot of details and followup to their threads
I went ahead and held the pool at MA level plus a little extra for 24 hours (starting yesterday)
Today, results:
9:30 am. FC 27.5 cc <.5 CYA 38-40. pool temp 65. bright sunny day
9:30 pm. FC 11.5. cc <.5
trying a oclt tonight

one quick question:
pool company added an algaecide to my pool. I made sure it was not copper based, but otherwise didn't get the name of what was put in.

do algaecides consume extra chlorine?

I'm really wanting to be done shocking this pool. Officially out of P.O.P., but appreciate input from the mods.

 

[Richard320]

...do algaecides consume extra chlorine?

I'm really wanting to be done shocking this pool. Officially out of P.O.P., but appreciate input from the mods.

I've read that some can. However, I've never used algaecide, so I have no first hand experience. (I never put anything in my pool unless I know what it is and what it will affect.)

 

[tltmom]

ok, continued problems, I think(?). please bear with me, moderators, you have been so helpful and polite about my pool ocd!

passed oclt on 5/7 fc was 11.5 at 10pm and at 5:30 on 5/8
water looks great, cc's <=.5

so all seems good but I still think I'm going through too much Cl.

For example, I have my swg on all day today @50%. according to my calculations, it should have produced about 2ppm Cl during that time. The fc went from 12.0 to 10.0 today, so that's 2ppm, for a total of 4ppm used up today, give or take a little. The weather was heavily rainy/cloudy, 65* water is about 63*. So it seems to me this is still excessive Cl use. I keep thinking if I'm going through this much Cl now, I will use a ton this summer.

I plan on following duraleigh's advice above, and will maintain 8.0<fc<10 for a week or two.

questions:
*does it seem like there's still something growing in my pool? (please say no, I'm so sick of shocking! ). There is nothing visible.
* the only thing I haven't done during this process is take off my light covers and checked the
niches. It's still to cold to try it. Also some plaster got slopped over the edges of the covers and I'm not sure I could get them off. Should I give this a try when I can stand getting in the water?
* would raising the cya help? It's only 40 now. I just didn't want to raise it untilI was sure I had the pool clean.

Thanks as always for your patience and advice.

 

[tltmom]

Just going out on a limb here, but I got to thinking...
If I went through 4ppm from a starting point of 12ppm, thats really only a 33% loss, which would be very normal I think given the cya, water temp, cloudiness etc.

Does that make sense?

 

[jblizzle]

Your last post makes sense. If you are switching to the SWG, then you should raise the CYA up to at least 70ppm so it does not have to work so hard.

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[tltmom]

I'll try to attach a picture, because we all like them!
Just wanted to say thank you to the moderators! Everything looks great, just fine-tuning water balance for swg.

FC 10.0 cc 0
pH 7.6
TA 80
CYA 50
CH 280
salt 3100
temp 65


I really appreciate everyone's assistance.

 

[Speedo]

I would invite myself over, but your 65 degree water is probably the same as mine.

I'm anxious to get home and see how much the sun helped today, going outside it feels so warm that the pool must be > 80. But I'm entirely sure it's somewhere around 75 at best.

However with yours being IG you could always get in and run out quickly. That would feel good today.