Weekly shocking problems

[mkotubs]

I've had my tub now for 5 weeks and every Saturday i've been cleaning (rinsing filters, and shocking), but i still seem to always have really high levels of FC and CC.   My dealer recommended the following, which I lowered this weekend but still seem to have high readings.  I'm using a Taylor test kit.



Dealer recommended:
5 oz of MPS  (Product is GLB Activate)
2 oz of Chlorine

This week before the shocking:
PH was 7.4
FC .5 PPM
CC .5 PPM
Alk  110 ppm

5 hours after shocking adding 4 oz MPS, and only 1 oz Chlorine

PH was 7.2     -->  I add PH up to bring back up to 7.4
FC 12 PPM
CC  3 PPM
Alk  110 ppm

24 hours after shocking
PH was 7.4
FC 3 PPM
CC  1.5 PPM
Alk  110 ppm

Something doesn't seem right, after reading a post here.  First it appears i'm double shocking my tub (MPS and Chlorine), is true?
I've realized that my MPS drops my PH as well, is this normal ?
I'm not sure why my CC is always high as well,  can MPS cause a false reading?   I don't think anything should be living in Chlorine level of 12 PPM.

Plus I don't like the fact that I can't use my tub on Saturday do to the high Chlorine level.  

Looking for help!!!

Thanks
    Mike

[In Canada eh]

mkotubs,


        Use the Mps as your shock (not dichlor) and use the dichlor as your daily sanitizer.  This should allow you to use the tub about 15 minutes after shocking.  You can shock on a weekly schedule or when the CC reaches about .5.

     It is normal for the MPS to lower the pH a little

The idea behind the chlorine method most around here use is that the chlorine residual is almost zero when you use your tub. Don't be nervous to allow it to fall to zero as long as you add some every other day or after each use

                                         Good luck

[mkotubs]

I use chlorine after each use.

What is causing my CC to increase with MPS shocking, is this a false reading caused by MPS?

[tileman]

Mkotubs, it's funny I am going through the same thing right know.
I shocked my tub for the first time this weekend with mps. My ph and alk were both a little high preshock. 7.8 and 110. Eight hours post shock and again today, I tested my water and ph was steady at 7.4 while alk was steady at 90-100. I was expecting a drop but not that signicant of one. I got lucky.
I also have had a CC reading around 4ppm. I had never had it that high before using mps. So to try and counteract it I am going to shock tonight with 2 tlbsp of dichlor.
Btw, mps has a ph of about 3-4 (I think) so naturally it will lower your tubs ph. This is normal and is why I shocked w/ it instead of dichlor which is almost nuetral at 7.0.
My Taylor kit advises one to shock with dichlor when you want to get rid of CC. I'm going to try this tonght and see what happens. I'll let you know how it goes.

CHAD

[Vinny]

You are using way too much stuff!

The dose for MPS is 1 oz for 250 gallons, I use about 2 oz per dose to shock (400 galon tub). I don't know specifically about GLB Activate but Sea Klear and other straight MPS is the 1 oz per 250 gallons.

Chlorine regular dose is 3 PPM 20 minutes after adding - the actual amount depends on the gallons of water and the active % of chlorine you use (52% will need more than 62% to get the same reading). Shocking dose is 10x the combined chlorine (CC) amount, so if the CC is 0.5 PPM you need to add at least 5 PPM of free chlorine. That's it.

I sometimes do use MPS and chlorine together. I add the MPS , let the tub run for 20 minutes and it is now "shocked". Then I add some chlorine to sanitize but only 2 teaspoons to get it up to 3 PPM.

And your CC reading will be wrong due to the MPS.

[tileman]

Vinny, so if my CC is at 3-4 how much dichlor should I shock my water with? If my math is right I would think about 2 tblsp.

[mkotubs]

If MPS causes CC readings to be false, do you know how long the false reading will last?

I checked the GLB Activate directions and they say 4 oz to superchlorinate 500 gallon  tub.  Isn't shocking and superchlorination one and the same?

[mkotubs]

Would the active percentage of Chlorine be labeled on the contains as "Available 55%"  ?

[tileman]

Yes that is correct mkotubs.

[Vinny]

Tileman, if you had 3-4 CC, your tub would be stinking like chlorine but to answer your question 30 to 40 PPM FC would be needed. On a 400 gallon tub that would be about 3 to 4 oz (1 tablespoon = 0.5 oz). The amount that is needed to get to a certain PPM really is dictated by the size of the tub (gallons) and the % active chlorine. I use 62% and I've seen it as low as 52% in dichlor and I think lithium chlorine is about 35%.

"Isn't shocking and superchlorination one and the same? " Yes and no. Shocking is used to get rid of the CC and organics. MPS shocks a tub only and has no killing power. It will get rid of whatever organic matter is in a tub until it's used up. Chlorine if used at a high enough concentration will oxidize organics and kill organisms but it has to be at that 10x the CC reading. Superchlorination means to add extra chlorine and that will definately kill organisms that are resistant to a regular dose but if the FC is less than 10x the CC reading then you got more CC being made. Some people make it a habit to add 10 PPM FC into the tub on a weekly basis or so. I tend not to do that too often, my superchlorination tends to be about 6 PPM about once a week or so and about 8 PPM whenever I feel the need.

To me the GLB Activate sounds like a MPS & chlorine mixture since you can't superchlorinate with MPS. I have used something like that in the past but I stick with separate MPS and dichlor. I use the product that I need at the time.

[mkotubs]

The GLB Acticate is only MPS,  i was adding chlorine as well during my weekly shock treatment.

Vinny, when you do your weekly routine, do you check the CC level before you shock your tub?  I've only been checking the PH first,  this week was the first time i checked every thing first before adding chemicals.  So since my before CC was .05 and after shocking the FC = 12ppm,  mu CC really should be zero right now, but since I add both MPS and Chloring sets up the false CC reading.    

Have you ever had your CC reading equal to zero using the taylor kit?  When testing my first drop, always turns the water pink, so my reading is .05.  I'll have to track this better going forward.

[In Canada eh]

Vinny,

   Sorry to post something and then leave it up to you

mkotubs,

    You can shock your tub when your CC reaches .5 by testing with the Taylor kit.  I personally shock on a weekly schedule.  Shock on Thursday and rinse filtres on Saturday, check pH and alkalinity on Sunday or Mondays.

    Vinny was right you are adding way to much stuff to your tub, you do not need to bring your chlorine level that high after soaking 3-5ppm will sanitze the tub

   As far as ever having a CC reading of zero with the Taylor kit,  I always have a CC reading of zero after my weekend chem routine

                                         Any other questions feel free to ask

[tileman]

Mps definetly gives false CC readings. I  checked all levels before my last soak about 1.5 hrs ago and they were all the same as previously posted except for my CC. It was now at 2.5 and dropping. So I added 2.5 tsps of dichlor an hour ago and I checked my FC,TC, and CC 30 min ago. My Fc was at 5 and there was no CC anymore. So this is how I know not to beleive the CC readings after shocking w/ mps. Hope that helps with your water chemistry mkotubs.

[Vinny]

Yes, there are times that my CC=0 but by the end of the week usually it is about 0.5 PPM which is why I use the 6 PPM as my superchlorination/shock. I always test my tub for chlorine when I believe the FC=0, if FC is slightly higher than 0 then I may test it or just hit it with MPS or extra dichlor. The good thing about MPS is that you can use your tub in about 20 minutes.

When your done with the GLB, I would advise you to purchase a more effective MPS, from the Sea Klear directions:

DIRECTIONS FOR USE
In pools, use 1 Lb. per 10,000 gallons of water every two weeks for light bather loads. 1 lb. per 10,000 gallons of water every week for heavy bather loads. In spas, use 2 oz. per 500 gallons of water every two weeks for light bather loads. 2 oz. per 500 gallons of water every week for heavy bather loads.

I'm not saying to use the Sea Klear brand but 4 oz will bring up your TDS at a quicker rate and it seems wasteful IMO.