Shock and hold for 24 hours?

[DonW]

Another noob question. I just want to get this straight. This will help me in closing and any other time that I'll have issues. You shock for the last time of the year and hold it there for 24 hours. How often do you check throughout the rest of the day? Every hour or so and adjust? Let's say you shock at 7pm. When would you check for the first time and when would the last time be before going to bed. Check again in the morning before the sun hits it and then at what frequency throughout the day? Till 7pm again the next night?
One last question. I'm getting ready to throw the winter cover on. Let's say my shock level is 31 ppm. How far do I let it fall before putting the cover on? At what point (ppm) do I actually put the cover on? Sorry if this is pointless to some, but I'm a little in the dark.

 

[duraleigh]

Hi, Don,

I don't winterize my pool so take my opinion with a very large grain of salt.

Assuming you have a clear pool and no reason to suspect algae, I would simply bring the FC to shock level and cover it up.

You certainly don't need to do an overnight FC loss test and I see no reason to hold your FC at shock for 24 hours. This is all assuming you don't have algae to begin with.

Others more experienced in closing may be more helpful but this will get the discussion rolling, at least.

 

[DonW]

Sorry duraleigh, you caught me. I do have an ongoing algae issue. Trying to clear things up if you will. I Still need instruction on Shock & Hold for 24 hours. I was thinking about winter closing and the algae problem and kinda got sidetracked. I suppose I should have put this question in the algae section

 

[duraleigh]

It's fine here for now. One of the mods may choose to move it for housekeeping but they'll let you know if they do.

Okay, so consider them as two seperate issues. 1) Clearing the pool of algae and then 2) closing the pool.

To clear it of algae, you need to bring the FC to shock level for however long it takes for these things to be met......
1. Your pool water is sparkling
2. Your CC's are .5ppm or less
3. You can hold your FC overnight without losing more than 1ppm.

Once that's done, the shock process is complete and then you can close. It is important the you continually test and add enough FC into your pool to keep it at shock value.....three times daily is not too much.

There's a good article up in Pool Scholl called "defeating algae". Read thru that and then ask more questions....lot's of people will help.

 

[DonW]

Dave, sorry to be a pest but----water is sparkling clear, FC loss is .5, and I've read the article on defeating algae already. I'm having problems with a persistant mustard algae and I want to shock at mustard levels. Just need the hourly sampling rate. I can just say that working second shift is not conducive to pool ownership.

 

[polyvue]

I'm having problems with a persistant mustard algae and I want to shock at mustard levels.

What is your CYA ppm? If zero, you might be able to continue shocking at 12-14 ppm, but if CYA = 50 ppm then you should be shocking at 30 ppm. More CYA, then higher still.

Suggest keying your pool specs and latest test results into The Pool Calculator, then press Calculate and refer to the bottom of the page for proper level of chlorine for (mustard) shocking.

 

[duraleigh]

Hi, Don,

Just reinforcing what polyvue has already said....

post a complete set of current test results

tell us what you are testing with...particularly the FC test.

 

[DonW]

TF test kit:
FC 9
CC .5
TC 9.5
CYA 80
ALK 220
PH 7.6

I've switched over to the BBB method about a month ago. I'm getting ready to shock at Mustard Algae levels according to Chem Geek & Jason's Pool Calc. My suggested FC levels at a CYA of 80 are 6 -9. Been keeping it at about 9 hoping the the algae would go away and not shock & hold for 24 hours. Frankly, I don't have 24 hours to sit pool-side taking samples and testing. It looks like now I will have to before I close. Hence my 2 part question earlier. A.) At what intervals do you test, & B.) At what level of chlorine do you put the winter cover on? duraleigh kindly already answered both parts. I hope that I didn't confuse anyone. I guess that I'm reading too much into the "shock & hold for 24 hours" thing. I always perceive a procedure to be more involved than it really is.

 

[polyvue]

Been keeping it at about 9 hoping the the algae would go away and not shock & hold for 24 hours

Based on CYA of 80 ppm, the recommended level of chlorine to perform a mustard shock is 44 ppm. If you're using 6% bleach, you would start with 9 gallons. Have plenty in reserve. Others may want to comment on a suggested schedule that would not be too inconvenient. Good luck.

 

[frustratedpoolmom]

You can test up to hourly and add more bleach if needed, the interval is up to you as to how long you want the shocking procedure to take. The more frequent in theory the shorter time overall. If one can only test/add bleach because of a work schedule say morning and night, the procedure will take longer than someone who can babysit the pool for 24 hours.

You can put the cover on at shock level.

 

[DonW]

Thanks frustratedpoolmom, I was kinda hoping for an answer from you. As in other posts and other advice that you had given in the past to other folks, you seemed to have the most practical approach. This is not to say however that I didn't appreciate advice from everyone else, I do! Thank you all for steering me in the right direction.