Shocking with Dichlor

[In Canada eh]

Our tub has gone a little cloudy and I would like to try shocking it with dichlor.  I know to raise the chlorine to about 50 ppm and the amount needed but , I would like to know how long it takes for the level to come back down to a usable amount.  I normally shock with MPS but  have heard a few people swear by dichlor for shock and would like to try,  I know chlorine shock works wonders in the pool.


                                                                  Thanks in advance

[Cola]

I use a scoop out of a can of baby formula.  Two scoops shoud do it.  If does not clear by morning add one more.  The chlorine will be eaten up fast so you can use it tomorrow no problem.  Just test it if you want
Steve

[Vinny]

You don't need 50 PPM if it just went cloudy ... use like 10 or so PPM. Chlorine with the proper PH will kill everything and you'll be surprised how much chlorine is left over as residule.


I would make sure your PH is in the 7.2 to 7.4 range (more killing chlorine in this range) and bump it up to 10. The 50 to 100 PPM chlorine is for killing biofilms and you may not be fighting this. Remember to use a clarifier to clear up the spa, chlorine along with ozone (remember that thread ) may not do it.  If you do use a lot of chlorine you can either use a neutralizer or plain old hydrogen peroxide - I think 1 oz kills 6 PPM chlorine.

The most important thing to remember is the contact time CT needs to be at a total of 2500 for a 99% kill - CT = PPM chlorine x time in minutes...  Remember I am a geek!  

[In Canada eh]

Thanks Vinny, going to give it a try this morning.

[In Canada eh]

Thanks Vinny and Steve, I put about 3/4 oz of dichlor (remember we have a small tub) in at about 8:30am and I just took a look and its clearing up well.  I think wife still had some sunscreen on when we were in on Friday night.  

I will test for residual in another couple of hours but it should be starting to fall

[Pathfinder]

I would make sure your PH is in the 7.2 to 7.4 range (more killing chlorine in this range)  

Actually,  you should be more like 7.4 to 7.6   as it has been proven that chlorine is 100% effective at 7.5  

[Dr. Spa™ Ret.]

Proven by whom???

When chlorine is added to water, a reaction occurs splitting it into hypochlorous acid and hypochlorite ions. The hypochlorite ion does not actively contribute to the sanitizing ability of chlorine (only 1%), but is an extremely strong oxidizer The hypochlorous acid is the active, killing form of chlorine and what does the actual sanitizing.

The amount of hypochlorous acid and hypochlorite ion that is produced when chlorine is added to the water is directly related to the pH of the water. At a pH of 6.0, 96% of the chlorine will become the desired "killing" form of chlorine,  hypochlorous acid. At a pH of 7.0, 75% of the chlorine will become hypochlorous acid and at 8.0 the hypochlorous acid concentration is only 25%. At a pH of 7.5 (the average spa) the amount of hypochlorous acid produced is about 50%.

[In Canada eh]

Thanks to all,

     Tub is all clear now and chlorine level is back to 4 ppm

     Sumthin ugly must have gotten in there

[TN__HOT_TUB]

sunscreen?     clarifier??    

Clean them filters.  Any time my water gets a bit cloudy, I shock with dichlor and clean the filters.  This seems to work pretty well for me.

[Dr. Spa™ Ret.]

Clean first, then shock.

Strange no ones ever mentioned this........... Chlorine has to oxidize everything in the water before it begins sanitizing. IF, you have dirty filters, filled with organic debris, a lot of chlorine is going to be WASTED oxidizing the dead material caught in the filter(s).

I expect to be given credit for this for all time to come  

sunscreen?     clarifier??    

Clean them filters.  Any time my water gets a bit cloudy, I shock with dichlor and clean the filters.  This seems to work pretty well for me.

[Brookenstein]

I clean, shock, then clean again (like 24-48 hrs later). {if the water was unusually cloudy}

[nicker]

just curious as why the though of Dichlor instead of MPS.  I find Dichlor never worked well for me and MPS is much nicer.   I switched almost 2 years ago to shocking each week with MPS and have not looked back.  I do use Dichlor for sanitizer and it works well for that.

But I guess its what ever works for each user.

[Dr. Spa™ Ret.]

Dichlor has 9 times the oxidizing ability of  MPS. e.g. 1 tsp dichlor = 9 TBS MPS in oxidizing ability. MPS tend to cost twice what dichlor costs, pound for pound. MPS adds to TDS levels significantly more that dichlor.. On the other side of the coin. dichlor add to cyanic acid (a work I can never remember nor spell.. as I'm sure someone will correct) As this acid increases, dichlors effectiveness decreases. You also have to wait much longer after shocking with dichlor before using the spa.

[sledjunkie]

I use MPS.
I find it lowers my PH, so I'm consistently balancing with baking soda.

[svspa]

Or you can toss a coin when you go out to the tub..

hmmm, dichlor shock or MPS shock today?

Taking the conflicted approach you can leverage the benefits of both. MPS when you want to use the tub that day, dichlor routinely for the superchlorination effect.

 

Steve