Shocking / Algae Removal Process - SHOCK DONE....NOW WHAT?

[Terrjam]

I discovered algae on pool floor yesterday and began the shock process last night. Per the Pool Calculator, my FC shock target for mustard algae was 22. I added the required bleach of 288 oz last night. This morning my FC is at 15.

I plugged the current FC of 15 into the pool calculator and put the target in of 22. Therefore, I still need to add 94 oz of bleach to get my target. Is this correct?

Once I reach my FC target of 22, then this needs to remain for 24 hours?

 

[JohnT]

Re: Shocking / Algae Removal Process

The important think about treating algae is to maintain the chlorine at shock level continuously until you get very little drop overnight and the algae is all dead. Mustard algae tends to grow on the shaded wall of the pool, so wouldn't likely be found on the bottom.

 

[Richard320]

Re: Shocking / Algae Removal Process

Yes, keep adding bleach to get it to 22. Every couple hours if need be.

 

[Terrjam]

Re: Shocking / Algae Removal Process

The important think about treating algae is to maintain the chlorine at shock level continuously until you get very little drop overnight and the algae is all dead. Mustard algae tends to grow on the shaded wall of the pool, so wouldn't likely be found on the bottom.

So if its not mustard algae, is it just regular algae? And do I still need to treat to FC of 22

 

[JohnT]

Re: Shocking / Algae Removal Process

The important think about treating algae is to maintain the chlorine at shock level continuously until you get very little drop overnight and the algae is all dead. Mustard algae tends to grow on the shaded wall of the pool, so wouldn't likely be found on the bottom.

So if its not mustard algae, is it just regular algae? And do I still need to treat to FC of 22

What is your CYA level?

 

[Terrjam]

Re: Shocking / Algae Removal Process

The important think about treating algae is to maintain the chlorine at shock level continuously until you get very little drop overnight and the algae is all dead. Mustard algae tends to grow on the shaded wall of the pool, so wouldn't likely be found on the bottom.

So if its not mustard algae, is it just regular algae? And do I still need to treat to FC of 22

What is your CYA level?

Yesterday my levels were as follows:
FC = 2.5
pH = 7.5
TA = 110
CYA = 35-40

That is when I noticed the orangish yellowish film on the bottom around edges and the "asterik shaped" matter in pool. I assumed it was algae and began the shock treatment. I have not tested the CYA today and think I only have enough left for one more test.

 

[frogabog]

Re: Shocking / Algae Removal Process

To answer one of your specific questions, holding at shock level for 24 hours is not what is recommended, but rather hold at shock level till you pass the three criteria:

1 - .5ppm or less CC
2 - <1ppm FC loss overnight (OCLT)
3 - water is clear

24 hours is rarely enough time for maintaining shock level. Disregard 24 hours. Some pools need to be at shock level for a week or two to get through this with sparkling clean algae free water. We just don't know how long it will take. Having a FAS-DPD test kit on hand and using it to maintain shock level sure will speed it up though.

 

[Terrjam]

Re: Shocking / Algae Removal Process

To answer one of your specific questions, holding at shock level for 24 hours is not what is recommended, but rather hold at shock level till you pass the three criteria:

1 - .5ppm or less CC
2 - <1ppm FC loss overnight (OCLT)
3 - water is clear

24 hours is rarely enough time for maintaining shock level. Disregard 24 hours. Some pools need to be at shock level for a week or two to get through this with sparkling clean algae free water. We just don't know how long it will take. Having a FAS-DPD test kit on hand and using it to maintain shock level sure will speed it up though.

First of all, frogabog, I love the little saying in your signature block!! Very cute!! :lol:

Please forgive me for my ignorance as I try to get this all. Before shock treatment last night, FC was 2.5. When I noticed orangish film on bottom, I shocked for target FC of 22 for mustard algae. This a.m. my FC was 15 so added as required by pool calc to raise tad more.

Criteria to meet before stopping shock:
1. .5 currently CC
2. I don't understand the <1ppm FC loss overnight . My FC obviously went up so this meets the #2 criteria, correct?
3. Water clearer than it was.

My FC is currently 12

 

[frogabog]

Re: Shocking / Algae Removal Process

You lost 7ppm overnight. So no, FC did not go up. Keep shocking.

In pool school, read about the OCLT. You'll test FC after dark and after adding enough to reach shock level. Then, before any sun hits the pool the next morning you test again. If you lose more than 1ppm overnight, continue shocking.

For CYA level of 40, shock level is 13ppm. Go add bleach now! (it's ok to add a little extra, so that you don't fall below shock level between testings)

 

[Terrjam]

Re: Shocking / Algae Removal Process

You lost 7ppm overnight. So no, FC did not go up. Keep shocking.

In pool school, read about the OCLT. You'll test FC after dark and after adding enough to reach shock level. Then, before any sun hits the pool the next morning you test again. If you lose more than 1ppm overnight, continue shocking.

For CYA level of 40, shock level is 13ppm. Go add bleach now! (it's ok to add a little extra, so that you don't fall below shock level between testings)

I'm confused. If my FC was 2.5 last night before shock. Then shocked to try and reach FC target of 22. This a.m. FC was 15 (at 3:30 p.m. was 12). Therefore, didn't my FC go UP by 12.5 overnight?

 

[Terrjam]

Re: Shocking / Algae Removal Process

Do I need to be testing any of my other levels (pH, CYA, TA) during this whole process or only the FC? Am I still aiming for the mustard algae shock level the pool calc gave me last night of 22? So I need to retest FC tonight and add needed bleach to reach 22, correct? Does my pump still need to run all night?

 

[Deb04]

Re: Shocking / Algae Removal Process

When they refer to FC going down, they mean without any intervention. So, you measure the overnight loss starting after dark and after you have added any chlorine.

During shocking, you only need to test FC and CC.

 

[Deb04]

Re: Shocking / Algae Removal Process

You want the FC to be, at a minimum, 13. So shoot for something higher than that (maybe 15) so that as it drifts down, it doesn't go below 13.

 

[Terrjam]

Re: Shocking / Algae Removal Process......AT WITS END

I just did my FC test for the OCLT tonight. My FC is 26.5 and the CC is 1. I am in tears and ready to give up. When I vacuumed tonight there was still some orangish yellow film on the outer edge of the floor (shady areas only). I have had the filter running since last night. It was almost 100 degrees here today and my kids couldn't go in the pool because I was shocking and now I don't know if they will be able to go in tomorrow.

Now what do I do? I obviously am not adding any more bleach, but can I shut my pump off for tonight and tomorrow I will be gone. I am so frustrated and don't know what to do.

 

[frogabog]

Re: Shocking / Algae Removal Process

Shutting the pump off will not help, keep it on, and make sure to clean the cartridge regularly while this is going on.

No OCLT tonight, sorry. I know it's frustrating, but this is the hard part that many have had to get past, and succeeded.

If you haven't been running the filter full time, that very well could be part of the longevity of your shocking. Don't turn it off until you're at normal levels, having passed all three criteria.

Tomorrow when you're gone, dose the pool up to mustard shock level for the day. It won't hurt the pool, and will allow you some room to not be there to maintain shock level. Check and re-dose when you get home. It's the best you can do, unless you have someone who will come and test/dose for you.

Most often once a pool owner's POP is about gone when they're doing everything we say... the corner turns. Just hang in there.

Got a picture you can show us of the water?

 

[Terrjam]

Re: Shocking / Algae Removal Process

It is storming really bad here w/ thunder and lightning so I haven't been able to go out and check my levels at all this morning. Makes me a little nervous to have pump running with storm.

Water actually isn't bad looking, it's clear but just not "sparkly". I can get picture when storm subsides and post.

Will water be cloudy with mustard algae? Yesterday I pulled filter out to clean and it was really orangish, is that a result of the algae?

 

[Terrjam]

Re: Shocking / Algae Removal Process....DAY 3 & OCLT RESULTS

Just checked my levels after OCLT.

Last Night @ Dark:
FC = 26.5
CC = 1

This a.m.:
FC = 20.5
CC = .5

 

[rjproulx]

Re: Shocking / Algae Removal Process....DAY 3 & OCLT RESULTS

Just checked my levels after OCLT.

Last Night @ Dark:
FC = 26.5
CC = 1

This a.m.:
FC = 20.5
CC = .5

Your FC is still eating some organic matter (the algae) overnight (6ppm worth), so keep shocking. I'm in your boat...and my kids haven't swam yet this year. But the methodologies they preach here work, so stick with it. It's frustrating for sure, but worth it when they can finally get in.

 

[Terrjam]

Re: Shocking / Algae Removal Process....DAY 3 & OCLT RESULTS

Just checked my levels after OCLT.

Last Night @ Dark:
FC = 26.5
CC = 1

This a.m.:
FC = 20.5
CC = .5

Your FC is still eating some organic matter (the algae) overnight (6ppm worth), so keep shocking. I'm in your boat...and my kids haven't swam yet this year. But the methodologies they preach here work, so stick with it. It's frustrating for sure, but worth it when they can finally get in.

Thanks for the encouragement. So what FC shock level am I aiming for and plugging into the pool calc? Not sure how much bleach I need to add now?

 

[rjproulx]

Re: Shocking / Algae Removal Process....DAY 3 & OCLT RESULTS

Thanks for the encouragement. So what FC shock level am I aiming for and plugging into the pool calc? Not sure how much bleach I need to add now?

Assuming your CYA isn't changing (and it won't unless you add more or remove water), your target shock level is still 13 (from reading up above). If your FC right now is 20.5, then you don't need to add anything. Just keep the pump running day and night.

If there is still algae being killed in your water, that'll likely drop down throughout the day, so test again right now or later this afternoon and if it's south of 13, bring it back up to 13 or more.