0 Chlorine Level?

[Snowbird]

I believe my test strips work since they measured 5ppm chlorine when when I tested in a gallon of water with a few granules.  I also got a high reading in my hot tub about 2 minutes after adding 3 tablespoons of dichlor.  However, when I tested about 12 minutes later I got a 0 reading again.  How would I know if I have biofilm? I don't seem to have white flakes and my water looks clear.

We also have a 385 and we started out with the same test strips.  I eventually bought a Taylor test kit and it showed how far off those strips were.  It was substanial.  Best thing you can do for yourself is switch.  It is a PITA since it takes a little more time, but the peace of mind is worth it.

We often go to Florida for 10 days or so and there are times when we just don't use the tub for a week for whatever reason.  I add 1/2 tsp Dichlor per person after each soak and super shock when the chlorine readings indicate to do it.  The Taylor booklet will help you with timing and amounts.  I do not use MPS any more at all.

Sounds like you are using a lot of chlorine.  Read up on the Vermonter method and things wil get better for you.

[spahopeful]

I took my water to a dealer to have it tested.  They said there was plenty of chlorine, but no free chlorine.  Their opinion was that adding the high doses of chlorine  to super shock the tub was bleaching out the test strips for all the readings and that it would be best to drain and refill the tub.  I am now just completing the drain and refill process.  

Snowbird:  How much dichlor do you use when you super shock your 385?  Are your chlorine levels around 0 24 hours after use?

[Snowbird]

I took my water to a dealer to have it tested.  They said there was plenty of chlorine, but no free chlorine.  Their opinion was that adding the high doses of chlorine  to super shock the tub was bleaching out the test strips for all the readings and that it would be best to drain and refill the tub.  I am now just completing the drain and refill process.  

Snowbird:  How much dichlor do you use when you super shock your 385?  Are your chlorine levels around 0 24 hours after use?

The only time I get a zero reading is when I return from vacation and haven't been dosing it regualrly.  In that case I follow the charts in the Taylor kit.

Your strips probably do not measure the different types of chlorine.

Free Chlorine (FC) "...is the workhorse of sanitization, killing germs and oxidizing organics."  2-10 ppm is acceptable and I shoot for 3ppm.  The Taylor manual says FC has no odor up to 10-20 ppm.

Combined Chlorine (CC) "...is the reaction of FC with amonia wastes from bathers.  CC causes the characteristic "chlorine odor"..." "CC has little sanitizing capability."

Total Chlorine (TC) "...is the sum of the FC and CC residuals..."  "TC = FC + CC"

"Breakpoint chlorination is achieved by superchlorinating (shocking the water with chlorine). Here, the chlorine level is increased dramatically in a short period of time."

"Superchlorinating to the breakpoint has the unique capability to destroy CC.  Chemists know that when FC is increased to ten times the measured CC, the level of CC will be reduced to a minimum:
"breaklpoint dosage = 10 X CC"

"adding less than the breakpoint dosage can create more CC!"  Remember that CC has no sanitizing value and it smells.

I am no chemist and can not explain this stuff.  that is why I am quoting from the Taylor manual that came with the test kit.  I follow it and it works.  I test once or twice a week and we use the spa 3 out of 7 days.  We always make sure we are clean going in and since it is an indoor spa, this isn't too difficult.

I add 1/4 tsp per person after each soak.  And maybe 1 tbsp each week (sunday usually) to shock.  It varies depending on the test readings and use.

I follow a specific order when testing...  1st TA, then pH, then Chlorine.
Occassionally (monthly?) I check Calcium and CYA.

The Taylor formula for water changes is: 1.3 of the volume in gallons divided by max nbr of daily bathers.

In my case 550 gallons divided by 3 equals 183
I is rare when anyone uses the spa other than my wife and I so... 183 divided by 2 equals 91.  I change my water every 91 days.. more or less.  This is about right because the water gets a certain feel to it when it needs changed.

My point here is to show you and others that the test strips is a pretty crude way to monitor your water, but if it works for you and you are satisfied, continue using them.  I tested the strips against the kit and the differences were very large.  So for accuracy and peace of mind, I chose the test kit.  It was a real PITA in the beginning but it is no big deal now and takes less than 5 or 10 minutes.

I got my kit from rhtubs.com at a decent price and he has lots of info on his site to help you out.

I am learning myself and there is plenty of help from this board.  They helped me alot.

[tony]

 

"Breakpoint chlorination is achieved by superchlorinating (shocking the water with chlorine). Here, the chlorine level is increased dramatically in a short period of time."

"adding less than the breakpoint dosage can create more CC!"  Remember that CC has no sanitizing value and it smells.

This is a good reason not to discount MPS as a shock, especially for beginners.  No matter how much you add, it will oxidize what it can.  If you add too much, it will linger until it has something to oxidize.  It is more foolproof than breakpoint chlorination, will help keep CYA levels at an acceptable level and will allow you to use your spa after shocking rather than waiting a day.  The downside is the increase in TDS, but that should not be an issue if you change your water at least every four months.

[Snowbird]

This is a good reason not to discount MPS as a shock, especially for beginners.  No matter how much you add, it will oxidize what it can.  If you add too much, it will linger until it has something to oxidize.  It is more foolproof than breakpoint chlorination, will help keep CYA levels at an acceptable level and will allow you to use your spa after shocking rather than waiting a day.  The downside is the increase in TDS, but that should not be an issue if you change your water at least every four months.

Tony, When I bought my tub my dealer had me using MPS with an ozonator and Nature2 stick, but no chlorine.  I ended up with open sores and itchy water logged skin.  I am not sure if it was caused by the MPS or the fact I wasn't using a sanitizer, but I am fine now not using any MPS.  But, I think you make a good point and since I am nearing my next water change I may experiment with MPS a little.  Thanks.

[tony]

Tony, When I bought my tub my dealer had me using MPS with an ozonator and Nature2 stick, but no chlorine.  I ended up with open sores and itchy water logged skin.  I am not sure if it was caused by the MPS or the fact I wasn't using a sanitizer, but I am fine now not using any MPS.  But, I think you make a good point and since I am nearing my next water change I may experiment with MPS a little.  Thanks.

I am a true believer and supporter of chlorine along with ozone and N2.  I have tried all kinds of variations of sanitizing using the three.  For two years I shocked my spa with dichlor.  I attempted using MPS before use and a dichlor shock weekly with not very good results.  I have settled to a little dichlor after use and shock with a non buffered MPS only when I register combined chlorine.  One thing I like to do is once per week add enough chlorine to raise the free chlorine level to 3-5 ppm.  This level is low enough to still use the spa, yet higher than what my teaspoon or so after use gets me.

I find it hard to believe that even Nature2 advocates using only MPS along with the minerals to sanitize.  It would never work for me.

[In Canada eh]

To super-chlorinate a spa, you need to get the chlorine level over 100ppm.  A 5ppm level of chlorine is the normal level 

Thanks for the correction ! OOPPS! There was supposed to be a zero behind the 5, 50 not 5. I hope this didn't cause any problems.