Is shocking necessary.........

94ukgrad

Member
Jun 19, 2010
14
Is shocking necessary if I maintain the clorine in the recommended range? Pool store man told me I need to shock at least once a week to actually kill the bacteria. My pool is crystal clear but now I wondering if it is full of bacteria?

Thanks for your comments.

Mark.
 

benavidescj

LifeTime Supporter
Apr 27, 2010
431
Fleming Island, FL
Nope, not necessary. I have never shocked mine. The only reason you need to shock is if you actually have organics in the water. The water will indicate this by not being clear, but most importantly the water testing you do will be your best indicator. If your CC test comes out greater than 0.5 it is an indicator that you have organics. Maintaining your chlorine level as recommended by this site will keep organics at bay and keep you safe. The pool store is just trying to sell you products.
 

kenmar

LifeTime Supporter
Apr 13, 2009
288
Schnecksville, PA
The site you reference appears to have a close relationship with the intheswim pool supply website.
As such, I believe the information presented (specifically as it relates to "Shocking") is biased.
Regular, accurate testing, along with following the basic principals detailed on this website truely can create a situation where shocking your pool is an infrequent (at best) activity.
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
Despite precab's opinion, the TFP philosophy is that if the level of FC is consistently maintained above the minimum for a given CYA level then shocking is rarely, if ever, necessary.

The only time shocking is necessary is if:
  • You have algae[/*:m:2hyw1d8q]
  • CC > 0.5[/*:m:2hyw1d8q]
  • Overnight FC loss > 1.0[/*:m:2hyw1d8q]
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,969
SouthWest Alabama
precab said:
In High temps and high humidity I shock weekly as it keeps chlorine from working as hard ...
There is no hard or not hard in how chlorine works. It works when there is something there for it to work on. It doesn't work less hard just because you add more once a week. I completely disagree with your statement.
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
precab said:
Disagree on this, and here is a decent link. In High temps and high humidity I shock weekly as it keeps chlorine from working as hard and I have zero issues or very low maint on chems in the Texas.

http://www.learnaboutpools.com/poolshocks.html
How does it "keep chlorine from working as hard"? What does that mean?

Does the chlorine from the trichlor stand aside and let the chlorine from the cal-hypo jump in and do the work?
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
94ukgrad said:
Is shocking necessary if I maintain the clorine in the recommended range? Pool store man told me I need to shock at least once a week to actually kill the bacteria. My pool is crystal clear but now I wondering if it is full of bacteria?

Thanks for your comments.

Mark.
If you read here long enough you will find some very technical stuff about sanitizing pools. Mostly (as far as I can understand, not being a chemist) the bacteria is handled easily at low FC levels. However, when using pucks it is pretty easy to have FC go to zero since it is never very high. One big rainstorm with branches and dirt in the pool, one dusty dog swimming, one toddler, a few snotty kids, any of those can use up more than 3 ppm and so the typical pool running at 2 or 3 ppm is at ZERO pretty quick. So, with a weekly shock, for at least one day, you will know that FC was high enough to kill bacteria.

I suspect that the reason they tell us that (I followed that advice also) is that if you use pucks exclusively for chlorination, the CYA level will get massively high really fast. If you use slightly less of the pucks, and add some cal-hypo type shock, then CYA rises but not as fast, and CH rises. Either of these can get too high and create big problems with algae explosions or calcium scaling. But the pool store is ready and willing to sell you additional products to solve those problems.

It is rare to find a good test kit in a pool store it seems. Perhaps if you knew what the chemicals actually are, what they are for, and how they change, you could put into your pool what it needs when it needs it, no more and no less.
 

Miranda

Well-known member
Jan 20, 2008
161
Northeast Florida
The same article linked above includes the following paragraphs (below). I would agree that it is factually incorrect and extremely biased. The author even misuses child safety as a theme to convince the reader. Little Plastic baggies of granular pool shock are more hazardous to small children (and pets) than heavy, child proof capped jugs of liquid chlorine!

http://www.learnaboutpools.com/poolshocks.html said:
Don’t use Liquid Shock!

Another type of shock that is widely available at any local pool store, hardware store and many grocery stores is liquid chlorine. This liquid chlorine is commonly used as shock, and used in place of chlorine tablets. Many pool owners believe this liquid chlorine is all they need to properly maintain a swimming pool, and unfortunately this is incorrect. Liquid chlorine is very inefficient and costly compared to properly maintaining a swimming pool using chlorine tablets and a weekly shock treatment. Liquid shock may seem easier to use than the granular shock for some pool owners because you simply walk up to the pool and dump the liquid in. The problem is that after you dump the hazardous liquid in your pool, you have to dispose of all the empty plastic bottles with the dangerous chemical residue inside. Granular pool shock is packaged in small, easy to use 1 lb. bags. If any children have access to the area where pool chemicals are stored it will be far easier to have an accident involving full or empty bottles of liquid chlorine, than an accident with bags of granular pool shock.

Granular Pool Shock is rated at a minimum of 47% available chlorine and available in concentrations up to 75%. If you look at the label on a bottle of liquid chlorine it will say that it is ONLY 10% SODIUM Hypochlorite (chlorine)!! This means you are paying for 90% salt water with every bottle you buy. The dosage for a standard granular pool shock is 1 lb. per 10,000 gallons of pool water. If you are currently using a liquid shock, you should compare the cost of a dose of liquid shock to the cost of a dose of granular pool shock. You will find that granular pool shock can offer you a considerable savings.
 

rastoma

Well-known member
May 17, 2009
249
Jasper, TN
precab said:
Disagree on this, and here is a decent link. In High temps and high humidity I shock weekly as it keeps chlorine from working as hard
Do you even know what you're doing when you 'shock' your pool?

Do you even know what SHOCK is?

Shock is not a product, it's a process. The process is nothing more than raising the CHLORINE LEVEL HIGHER for a limited time.

When you buy that product that says shock it's nothing but chlorine just concentrated.

If you keep your chlorine levels where they are supposed to be to begin with, there is no need to shock...err.... add a HIGH dosage of chlorine.


precab said:
and I have zero issues or very low maint on chems in the Texas.
So do the HUNDREDS of people on this forum who DON'T shock. Buy a good test kit and learn to use it and you'll rarely need to shock, if ever, your pool.
 

DWSPool

LifeTime Supporter
May 21, 2010
84
Southern Indiana
Precab: how do you know you actually need that weekly shock? You may simply have a very high (but perhaps unnecessary) factor of safety. I understand your reluctance to not shock - if, for some reason, your pool is on the edge of algae outbreak, but you can't see it (or you don't have the test results for CC), you may not want to experiment, get an algae outbreak, then have to work harder to get ahead of it. On the other hand, you may be spending money on chemicals unnecessarily.

If one doesn't have accurate test results, the CYA level is unknown, or if the pool liner and/or filter is harboring lingering algae and other organics, I can see why the overly conservative weekly shock approach is recommended. And, as pointed out throughout this web site, if they CYA level is very high (> 100, for example), then a whopping dose of chlorine may be necessary on a regular basis.

I have been running our pool for over a month with only one elevated chlorine treatment - during the second week after opening , the chlorine level got to the low side for a couple of days, the water was becoming cloudy, and the CC was right at 0.5. I raised the chlorine level up to 12, and it gradually came down to 6 or 7 in a couple of days, water cleared up, CC is non-detectable, and chlorine is maintained between 3 and 5 (CYA about 40). I have operated the pool at the recommended FC range for the CYA level for more than 3 weeks, and through heavy bather load of 4th of July, 3 weeks of high humidity, +90 degree heat, and the water is crystal clear - no shock during this time.

Anyway, that's my 2 cents-worth.
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
That "learnaboutpools" website is the anti-TFP. It looks like a company whose bread and butter is tabs & granular shock striking out against knowledge and common sense.

I love how in their "don't use liquid shock" rant they refer to liquid shock as "hazardous liquid" but never mention that their products are also hazardous, and at the same time touting how much more concentrated their product is. Wouldn't that make their product more hazardous? :hammer:
 

poolgirl22

Platinum Supporter
LifeTime Supporter
Apr 14, 2010
595
Stephens City, VA
Ditto svenpup...

I will add that liquid chlorine has been far less hazardous to work with for me. That automatic chlorinator is the most hazardous piece of equipment I've ever had the misfortune of using. You open up the lid to that thing and noxious permeating chlorine fumes overtook the area around you. My eyes stung, my lungs hurt, and no matter how long I tried to hold my breath, I still ended up choking on the fumes. I often ended up with swollen itchy eyes as well. Add to this the mixing in a bucket of powdered shock and it's no wonder I was fed up with my pool. So, no thank you. I will stick to LC. Even my liquidator doesn't smell like that chlorinator when I open it up.
 

DWSPool

LifeTime Supporter
May 21, 2010
84
Southern Indiana
Definitely in agreement with you svenpup and poolgirl22 - we still use the tablet chlorinator every so often to allow a few days of asbenteeism (would like to buy a Liquidator; perhaps next season), but we have to hold our breath to keep from choking on chlorine gas - same is true when opening the tab bucket.

There's no "free lunch" with any method of sanitizing a pool - we had a SWCG for a few years and having to clean every couple of weeks with muriatic acid and adding acid to keep the pH down was no picnic. Just opening a bottle of muriatic acid on a warm, humid day can clear your sinuses for a week.
 

mitch08

Well-known member
Jun 30, 2008
391
Suffolk County, NY
poolgirl22 said:
Ditto svenpup...

I will add that liquid chlorine has been far less hazardous to work with for me. That automatic chlorinator is the most hazardous piece of equipment I've ever had the misfortune of using. You open up the lid to that thing and noxious permeating chlorine fumes overtook the area around you. My eyes stung, my lungs hurt, and no matter how long I tried to hold my breath, I still ended up choking on the fumes. I often ended up with swollen itchy eyes as well. Add to this the mixing in a bucket of powdered shock and it's no wonder I was fed up with my pool. So, no thank you. I will stick to LC. Even my liquidator doesn't smell like that chlorinator when I open it up.
This is so true. I can't really complain about tablets because I used them successfully for many years but MAN-O-MAN, opening that thing up is dangerous!!! :hammer:

A couple of times I forgot to hold my breath and got my face too close to it and I thought my head was gonna explode. That can NOT be healthy. :shock:

When I use 12.5% bleach (Liquid Chlorine) I can't smell a thing. And when the plastic jug is empty, I fill it with pool water a bunch of times and empty it into the pool...
So when I throw it out, theres pretty much nothing in there at all.

I started using bleach less than a week ago and am happy so far. But its a serious job right now constantly doing it. I might get a liquidator, or I might do a combination of bleach / tabs.
Not sure yet.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
The learnaboutpools.com website has a WHOIS registration using Domains by Proxy, Inc. so they are hiding their identity/ownership. The about page makes it sound like some pool owner put together the site, but virtually every link on the website that leaves the site goes to intheswim.com (as Jason noted [EDIT] CORRECTION: It was kenmar in this post [END-EDIT]). So this appears to be a lame attempt at deceptive marketing trying to pretend to just be a pool owner putting together info on swimming pools, but really it's an advertising site for a corporation.
 

Other Threads of Interest