Shocking

[devilwoman]

Great information thanks!!!

[KarlXII]

I generally leave the cover off 20 minutes when using 6 PPM for shocking and 1 hour if I hit it harder with more chlorine. I'm not that stick with this rule at times but if I have the time (weekends) I try to stick with this.

Regular chlorination, 3 PPM, gets about 5 min or less.

How do you know how much chlorine gives you 6 PPM and 3 PPM?

[Tatooed_Lady]

I would think it depends on your water and how much the tub holds. If I recall correctly, 2 TBSP of dichlor in MY tub (500 gallon) gets to about 10ppm, that's with a fresh fill.....so I figured 1 TBSP is 5ppm, etc....You could test your own, see what you come up with.....

[drewstar]

How do you know how much chlorine gives you 6 PPM and 3 PPM?

By testing the water 10 minutes after adding the chlorine.

[Tatooed_Lady]

Hmmm....and then there's that.... *lol* what drewstar said.

[spahopeful]

Are the Leisure Time test strips an OK way to test these levels?

[drewstar]

Are the Leisure Time test strips an OK way to test these levels?

That's what  I use and have had no problems.

[devilwoman]

Vinny,

My normal dichlor dose is 1 teaspoon after I get out of the water.  When I shocked I use 3 tablespoons of dichlor.  Too much I know my calculations were off because...well it's a long story...but mostly because I'm stupid.   Should the free chlorine level be close to 0 the next day say 24 hrs later or will it be longer before it comes to 0.  I realize now why people use MPS to shock so you can use the tub sooner.  The water smelled ok, but the reading was definately over 5ppm 12 hours later.

[Vinny]

Vinny,

My normal dichlor dose is 1 teaspoon after I get out of the water.  When I shocked I use 3 tablespoons of dichlor.  Too much I know my calculations were off because...well it's a long story...but mostly because I'm stupid.   Should the free chlorine level be close to 0 the next day say 24 hrs later or will it be longer before it comes to 0.  I realize now why people use MPS to shock so you can use the tub sooner.  The water smelled ok, but the reading was definately over 5ppm 12 hours later.

It could be longer than 24 hours but it's OK to soak in chlorine. With everything that's said here if you read "the manual" we're supposed to put chlorine in before not after. But thinking logically IF we soak with close to 0 chlorine and put in a dose we're still killing the nasties. The only problem is if someone gets in the tub with really bad nasties there's nothing to kill it while you're in the tub.

In my tub I use about 1 - 2 teaspoons after soaking, this gives me 1.5  - 3 PPM chlorine. My tub is 400 gallons so your tub would yield a little less readings than mine.

Too much chlorine is not bad and actually is probably good since if something was to be growing, that much will definately knock it out unless it grew to a biofilm mass then it wouldn't do too much. Regular chlorination and keeping water flowing to all parts of the tub will stop anything from getting to that level.

As far as soaking in "high" levels of chlorine ... MY tub on the last water change developed chlorine lock. My chlorine would stay for days with what ever amount of chlorine I put in. I had thought that the problem went away and I shocked the tub, soaked in it, added chlorine  ....  well by the end of the week I got in and smelled chlorine and thought it was combined chlorine. I took out my test kit and found it was WAY HIGH chlorine. It was over 20 PPM, my tub still had the problem but I wasn't aware of it. If you do soak in chlorine, even at 6 PPM I don't believe it'll hurt you (may kill the suit though - no ill effects on mine).

[Gomboman]

Vinny and Tony or anyone who cares,

Do you have a Taylor Pool & Spa Water Chemistry book? If so, turn to page 31. Under the section "Disadvantages to MPS" it says "Unlike breakpoint chlorination, will not remove combined chloramines".

This seems strange to me. Is this correct? When I shock with MPS I can't seem to completely eliminate my combined chlorine like I can with dichlor. There's always a slight tint of purple when I test for combined chlorine using my Taylor Test Kit after shocking with MPS. Maybe it's just me.

[anne]

Gomboman, that you for asking that! I KNEW I saw that statement somewhere, and now I realize it was from the tayor book. I wondered about that too.

[Vinny]

I've read that myself and then read the label on a MPS bottle. It's contradictory in their terms according to the bottle.

I have an older Taylor booklet (2003) and it doesn't have that statement in it. My new one (2004) does. Maybe something was found out between the 2 publishings, maybe MPS doesn't work or maybe there is a misprint in the Taylor book.

I really don't use MPS that often to experiment in my tub with it. I tend to have very low combined chlorine and a large (6 PPM) dose takes care of breakpoint chlorination in my tub.

The problem I see with MPS is it leaves the kits with a false reading on combined chlorine, so it's impossible to really determine if you have any unless you stopped soaking, didn't add chlorine and tested your water with something every day for a week (?) to see if the combined chlorine goes away.

[tony]

Mine does not say that either.

[anne]

The problem I see with MPS is it leaves the kits with a false reading on combined chlorine, so it's impossible to really determine if you have any unless you stopped soaking, didn't add chlorine and tested your water with something every day for a week (?) to see if the combined chlorine goes away.

MPS interferes with chlorine reading? Just combined, not free? For how long after adding- a week? How is that possible, if some people shock with it weekly?

[tony]

MPS interferes with chlorine reading? Just combined, not free? For how long after adding- a week? How is that possible, if some people shock with it weekly?

It interferes with chlorine reading right after you add.  Wait an couple of hours to test after adding.  It is not an issue.