Superchlorination Method

[baudilus]

I was researching shock methods (since I usually just pour liquid or powder at the returns and add the step of brushing when I use the powder), and happened upon mention of the "recirculation" method.

I was instructed to never add shock directly to the skimmer as the heater core and other components can be damaged, so i never thought about it, but it seems sound. Basically, you turn your multiport valve (necessary for this method) to recirculate, and then slowly add the powdered shock to the skimmer closest to the pump (i.e. with the most suction pressure). Wait until the "white cloud" stops coming from the returns, and then turn the valve back to filter (not forgetting to brush the walls and bottom of the pool).

I did some searching and haven't found much mention of this method, but another site recommended leaving the valve on recirculate for 24 hours to allow the shock to really circulate and do it's thing before filtering the water again.

I am surprised by the lack of mention around the web on this, because it seems like the quickest and most effective way to distribute shock, especially if you have a lot to add. Not even my pool professional or my local pool store mentioned this. It would certainly be easier since they sell 5 lb tubs at a cheaper rate than buying five one-pound bags. I happen to need to add 5 pounds at a time.

So my question is, if you have an in-ground pool, what method do you use? Have you tried the recirculate method? Doesn't the recirculate still push water through the heater?

 

[bk406]

All recirculate does is bypass the filter media. The water still goes thru the heater and any other peripherial equipment. If I use Di-chlor granules to shock, which i do on opening the pool, i broadcast it over the top of the water. Most of the time to shock i pour liquid chlorine, AKA bleach in front of a return in the deep end.

 

[Bama Rambler]

Unless you need to add CYA you should only use liquid chlorine to shock. By using Dichlor ot Trichlor you're adding CYA every time you shock so you'll eventually have too much CYA and your FC (free chlorine) level will have to be increased to match.

I wouldn't suggest using the recirculation method for the reasons bk406 mentioned. The shock still goes through all the equipment except the filter media.

 

[bk406]

Unless you need to add CYA you should only use liquid chlorine to shock. By using Dichlor ot Trichlor you're adding CYA every time you shock so you'll eventually have too much CYA and your FC (free chlorine) level will have to be increased to match.

.

I should have clarified. Yes, do not use di-chlor unless you need to add CYA. I typically need 30-40 ppm at opening (i have a SWG and run my CYA around 60 ppm during the season so i can kill 2 birds with one stone so to speak at opening by using di-chlor for a couple of weeks).

 

[baudilus]

I can never seem to get my CYA up anyway, plus I believe the shock I get is calcium hypochlorite or something. Although it's been about 5 months since I last looked at a label.

I know the tabs I was using were tri-chlor.


This year I plan to really stay on top of my levels and have my pool water perfectly clear for more than a week at a time, with the help of TFP, of course.

 

[duraleigh]

Hey, baudilus, welcome to the forum!! :lol:

Like the others, I see no advantage in recirc. at all

Common sense dictates the application of whatever type chlorine you use to shock your pool. In my case, the skimmer works very well. It is located approximately 75-80 feet from the equipment and gets diluted by that trip plus an intervening skimmer along the way that further dilutes it.

For others, the skimmer is usually much closer to the equipment so liquid chlorine in front of a return is likely the best.

Broadcasting powder can be troublesome if the powder settles undissolved onto the pool floor and is allowed to remain.........in that case, common sense would tell you to brush it thoroughly or perhaps pre-dissolve it somewhat or SLOWLY add it thru the skimmer.

Like most things, there's more than one way to skin a cat and the best way to shock your pool may be just slightly different than what others do. In any case, always let your good judgement prevail.

PS - We are dedicated to using "shock" as a verb and not a product that you buy. We're swimming upstream against the pool chemistry manufactureres but we keep trying :-D :-D

 

[geekgranny]

The few times I've broadcast powder into a clean pool I do it with the Polaris 280 (pressure) running using the leaf bag. It certainly does keep any undissolved powder, whether filler or chem, stirred up and the coarse bag doesn't trap the powder or granules.

In the past, before TFP and BBB, keeping the chlorine levels good using BBB, I've used the powder/granules to quickly lighten the constant staining from the "fake pears" that drop in to pool. Many times I left it over night. The "fake pears" immediately sink and stain within minutes. Brushing does nothing to them. This was not the best treatment for the plaster and possibly contributed to the scaling in that area on shallow bottom and steps (along with way wacky and disregarded numbers). After starting BBB and keeping chlorine at the high end, per Pool Calculator, the staining does not get as dark. And I learned to live with it only using the granules when company was coming, which isn't very often. With so much backwashing, with my very undersized old filter, I never had to worry about too much of anything rather spent time and money constantly upping, CA, TA, CYA, Cl, etc., (starting in mid 2009 when switched to BBB).

I've always attributed the longevity of all the plastics, including the plastic in grids of DE filter, to so little use of chlorine, which probably has some basis (I used Ionization for years) BUT my water was unhealthy and other bad things happened due to out of whack numbers. Before going to Ionization I used chemical feeders for chlorine pucks (that was several years old when we bought house/pool) and then switched to Bromine Feeder. The plastic in and near the feeders did brittle up. Because of so much backwashing, weekly or a little longer, when I was using chlorine or bromine the grids in the DE filter lasted about a year (too big a pump for filter too) but when I changed to Ionization the grids, with same amount of backwashing, and too little sanitizer in system, the grids lasted at least two years. So it seems that heavy concentration of chlorine/bromine sanitizer does cause some plastics to age more quickly. I certainly would keep concentrated chlorine as far away from all parts/surfaces after my past experiences and studying TFP.
gg=alice

 

[baudilus]

...perhaps pre-dissolve it somewhat or SLOWLY add it thru the skimmer...

Given that I need to 5 1-lb bags of cal-hypo to raise my FC by 10 PPM, I'd be sitting at the skimmer all day.

I have used liquid chlorine (5 gallon containers from the pool store for around $18 each) and find those giant containers unwieldy and almost always get a little splash. One of my local retailers was selling the 1-lb bags for around $3 per bag, so the cost was around $15 to raise FC 10 PPM.

Based on the pool calculator and the cheapest price I can find for 6% bleach in my area ($2.69 for 182 oz @ Target), that cost is reduced to $13.45 per 10 PPM - not a drastic reduction, but at least I can get liquid's convenience at powder's price, so going forward I'll be buying up all the bleach I can get my hands on.

 

[baudilus]

The few times I've broadcast powder into a clean pool I do it with the Polaris 280 (pressure) running using the leaf bag. It certainly does keep any undissolved powder, whether filler or chem, stirred up and the coarse bag doesn't trap the powder or granules.

I was told by my pool company that shocking the pool with the cleaner inside may damage it, so I never tried it.

 

[duraleigh]

Given that I need to 5 1-lb bags of cal-hypo to raise my FC by 10 PPM, I'd be sitting at the skimmer all day.

More importantly, Cal-Hypo add Calcium to your pool and draining is the only way to reduce it. Do you know what your Calcium Hardness (CH)
is?

 

[baudilus]

Given that I need to 5 1-lb bags of cal-hypo to raise my FC by 10 PPM, I'd be sitting at the skimmer all day.

More importantly, Cal-Hypo add Calcium to your pool and draining is the only way to reduce it. Do you know what your Calcium Hardness (CH)
is?

I don't recall what it was at last test, but I do remember that it is always quite low based on the recommended range and the recommendation is always to add some unholy number like 500 lbs of calcium to bring it to normal ranges, but i never worried about it being low because it's a vinyl liner.

I suppose eventually I'll have to make sure not to add any more calcium, but right now it's not a problem.

 

[geekgranny]

The few times I've broadcast powder into a clean pool I do it with the Polaris 280 (pressure) running using the leaf bag. It certainly does keep any undissolved powder, whether filler or chem, stirred up and the coarse bag doesn't trap the powder or granules.

I was told by my pool company that shocking the pool with the cleaner inside may damage it, so I never tried it.

I wasn't really using the granules/powder for shocking when I used the Polaris so the Cl values were not very high. That's a good point though. After finding TFP, and learning to always keep Cl levels (and others) on target, I hope to never have to shock my pool again. If I do mess up, I'll be certain to keep the cleaners out of pool for a few days if I ever have to shock. Thanks.

BTW..... I'm using Cal Hypo in a floater right now until I can get my CH levels back up (and liquid 6%) but chlorine demand has been really low with almost no sunshine past two months. With all the water I've had to let out of pool, rain and backwashing every few days, I've been struggling for months to keep CH up. I've probably purchased, at least 100 lbs of Calcium Chloride in past 6 months and it has still always been under desired levels. Same with CYA. With my new filter going in when the weather warms (hopefully this weekend) and dramatically less backwashing I should be able to maintain those much better.

gg=alice