Free Chlorine

[The_Pa._Lady]

I am trying to SHOCK my tub.  But I can't bring my Free Chlorine up to 10ppm.  It will come up to 3-5ppm then drop to 0ppm.  I started out with small doses of MPS and kept increasing to bring it up, ( used approx. 1/2 cup of MPS ) but it still does not come up to 10ppm.  I even added some Diclor thinking that would bring it up, it brought it up a bit higher, but then dropped down again.  What should I do?  I had the jets running between each application for 30 min.  What should I do?  

All other readings are good.  Water is clear as a bell.

Thank for any and all help.

[anne]

dichlor is chlorine, so that is what you have to add to get the free chlorine level up. MPS is a strong oxidizer, and so it will oxidize combined chlorines and eliminate them, but it wont increase your FC. I'll let the more knowlegable folks here take it from there.

[tony]

I think at 1/2 cup MPS, your spa is shocked.  MPS will not raise your free chlorine levels.  Just follow the directions on your bottle of non chlorine shock.  No need to test for chlorine levels unless you are attempting to shock by reaching breakpoint chlorination by adding dichlor to 10 ppm.

I personally like using MPS to shock.  I find it easier, more complete and you can use your spa right after.

[George]

Shocking is to Oxidize the tub.  MPS is an Oxidizer.  Clorine is a sanatizer, and can be effective as an Oxidizer at 10 ppm.  Most people shock with MPS not with clorine.  You only need to bring Clorine levels to 10 ppm if you are trying to shock (Oxidize) with Clorine.  Shocking with Clorine requires waiting for the Clorine levels to return to safe levels before using the tub, which in some cases can take days.  When shocking with MPS it is safe to use the tub within 30 minutes, many here say you can use it right away, but I would recommend waiting 30 minutes.  

Using 1/2 cup of MPS is to much, you should use the amount shown on the bottle, mine says 3 Tablespoons per 250 gals of water.  High levels of MPS might be irritating to the skin.  There are not very good tests for MPS levels because Clorine interferes with MPS tests so most people don't test for MPS levels.

[hottub.pool_boy]

way to go people. bravo.

[kervis]

way to go people. bravo.

8-)

[anne]

No need to test for chlorine levels unless you are attempting to shock by reaching breakpoint chlorination by adding dichlor to 10 ppm.

Not trying to be argumentative, but I want to make sure I understand this correctly: isn't breakpoint chlorination reached by achieving approximately 10X your CC level, as opposed to a specific level like 10ppm? So 10ppm would be fine if your CC was at 1.0, but not if it was 2.0?

Perhaps it is a moot point: I have never seen my CC at higher than just under 1.0.....does it just not generally get higher than that if you are on top of things, so 10ppm is a good rule of thumb?

[tony]

You are exactly correct, Anne.  10 ppm tends to be a level that you would feel would get the job done generally.  In reality, you may only need to get to 6 or 8 ppm or (gulp) you may need more than 10.  The problem with superchlorinating to shock is if you don't reach breakpoint chlorination, you haven't shocked.

[The_Pa._Lady]

Thank you everyone for helping with this problem.

I wanted to superchlorinate the water, and I sure did!!!

I tried MPS first but it didn't bring the reading up to 10ppm, then I added some dichlor later, and that brought it up to 10ppm.

Now my problem is, how do I get the total chlorine and the free chlorine down to an acceptable range so we can use the tub.  Is there a quick remedy or do I have to wait it out?  It hasn't moved from the 10ppm since yesterday afternoon.  I have my cover halfway open, hopefully that will help.

Help! Help!   Thanks again.

[windsurfdog]

You are halfway there!  Just open that cover and let the sun shine in...the sunlight will break down the chlorine for you.  I wouldn't hesitate to soak in 5 ppm or so...I don't think you would have to let it stay open for very long to reach that point.

[Tatooed_Lady]

I'd had this goofy idea on how to use up the extra chlorine....grab a couple sweaty socks, toss 'em in, and let the chlorine work!  
Anyhow....the level sits at 10ppm (or other high number) because it's got nothing to eat up, if I'm logick-ing my way thru this correctly.....so either sit and wait (possibly days) for the levels to drop....or 'help' them down...through off-gassing, sunlight, or whatever.
Yes?  :-/

[Vinny]

SOAK!!! You might be drinking 3 PPM chlorine. Chlorine may have no effect on you. People wash with bleach and water probably have 50 PPM solution and using their bare hands.

I've used peroxide to eat up the chlorine. Apparently Baqua has a chlorine neutralizer.

[Gomboman]

Thank you everyone for helping with this problem.

I wanted to superchlorinate the water, and I sure did!!!

I tried MPS first but it didn't bring the reading up to 10ppm, then I added some dichlor later, and that brought it up to 10ppm.

Now my problem is, how do I get the total chlorine and the free chlorine down to an acceptable range so we can use the tub.  Is there a quick remedy or do I have to wait it out?  It hasn't moved from the 10ppm since yesterday afternoon.  I have my cover halfway open, hopefully that will help.

Help! Help!   Thanks again.

Your chloring readings were probababy not accureate if you added MPS to the spa. MPS masks chlorine readings quite a bit.