Where did all my chlorine go

[rick_in_cleveland]

I have a 2003 Reward, N2 and ozone.  I clean the filters every 7-10 days, add 2 tsp dichlor after each use and 4 Tblsp once a week as shock.  Ph is 7.4 Alk is 120 water is 2 months old and its being use by 2 people for 20 mins 3 x week.

Now the question

I shocked and didn't use it for 4 days.  On the 4th day it was a LITTLE cloudy so I schocked it with the normal 4 Tbls.  The next day it wes still cloudy and no Cl on the test strip.  I reshocked with 4 tbls and the next day again still a LITTLR cloudy and no Cl on the strips.  I then shocked with 8 Tbls and after 40 hrs it wss clear but again no chloriine on the strips.  4 hrs after shocking the strips are dark purple so I know they are OK.  The only change is a recently added scum bug.  So why is it taking so much chlorine?

[Drifter]

Ummm are you sure your "Shock" has chlorine in it?  Mine didn't. The "shock" product I was using was strickly a "sanitizer".  I recently purchased "Enhanced Shock" which I am told contains a small amount of chlorine.  I was told use the "enhanced shock" after every use and  add chlorine 2-3 times per week. As to where it goes? It gets burned off. Hope this helps!

[Drewski]

The situation you describe for the amount of dichlor used is "normal," given the temperature of the water and an assumption of typical usage.  

Your problem occurred because you didn't keep up your daily cycle of adding chlorine.  "Shocking" only adds high levels that quickly fall. To an extent, the same thing is true about adding a little bit each day, think of it as "mini" shocks.  Once you change a routine, stuff happens.

Consider an all-in-one product with buffer, clarifier, stabilizer and dichlor, this may help.

Hope this provides an answer...

Drewski

[twok99]

Rick,

I essentially have the same problem.  We use our tub a little bit more than you do, 2 people, 5-6 times per week for 30 minutes, but I do have a large tub almost 500 gallons of water.  I'm using a daily 1 1/2 tsp dose of dichlor, N2, ozone and shock with 3 tbls every week.  I have found that when I hit the 6-7 week point my daily/weekly doses are not keeping the water clean and increasing the doses just make the water smell and feel bad.  I get cloudiness and my pH starts to drop.  Why?  The two possible causes I have heard about are TDS and/or Cyanuric acitd levels affecting the effectiveness of the sanitizer.  As a result I change my water every two months.  This has been pretty consistent over the two years I have had my tub.  I did try broimne once and the water was lasting longer, but I just could not stand the smell.  I am going to try one thing different with the refill I just did a week ago.  After 4 weeks I'm going to partially drain the tub (maybe 1/3 of the water) and see if reducing those concentrations has any effect.

[rick_in_cleveland]

A while back I was wondering if I changed or even partially changed out the water before the 4 months can I keep using the N2 cartriidge.  This is what the N2 folks said

"You will need to replace the Nature 2 whenever the water is drained and refilled.  This is because you loose a good percentage of the silver ions when you drain the spa, and their is not enough in a depleted cartridge to
bring it back up to the proper level.  So you will need to change the Nature 2 cartridge."

My guess is if you  change out 1/2 the water you will need to change the N2 cartiridge as well.  

Nice to know someone has the same problem after 2 months.

Rick

[Spatech_tuo]

I'd probably put a new one in but still leave the old one in a while longer as well to get full use out of it.

[txwillie]

A while back I was wondering if I changed or even partially changed out the water before the 4 months can I keep using the N2 cartriidge.  This is what the N2 folks said

"You will need to replace the Nature 2 whenever the water is drained and refilled.  This is because you loose a good percentage of the silver ions when you drain the spa, and their is not enough in a depleted cartridge to
bring it back up to the proper level.  So you will need to change the Nature 2 cartridge."

My guess is if you  change out 1/2 the water you will need to change the N2 cartiridge as well.  

Nice to know someone has the same problem after 2 months.

Rick

That's interesting. I guess the Spa Frog has the same requirement? I've changed my water out at 2 months since I've had the spa, but have only replaced the Frog mineral cartridge at 4 months. Any Marquis guys or others who use the Spa Frog wanna comment on that?

txwillie

[Soakin]

...I shocked and didn't use it for 4 days.  On the 4th day it was a LITTLE cloudy so I schocked it with the normal 4 Tbls.  The next day it wes still cloudy and no Cl on the test strip.  I reshocked with 4 tbls and the next day again still a LITTLR cloudy and no Cl on the strips.  I then shocked with 8 Tbls and after 40 hrs it wss clear but again no chloriine on the strips. ... So why is it taking so much chlorine?

Here's my opinion, based on similar things happening to our tub on occasion.   Obviously, the "little cloudy" was something growing in the tub.  The chlorine you added was used up trying to oxidize the organic material in the tub and kill the nasty, but wasn't enough to overwhelm the problem, so it would regrow overnight.  The same dose the next day had the same result.  When you finally added the mega-dose you took out whatever was growing in there, so the water cleared up, but still left you with no chlorine residual because it just enough to kill the problem, but not enough to leave a residual.

This could be a one time problem, but it may also indicate that you need a little more sanitizer on a regular basis.  Remember that each spa is a unique situation and dosing recommendations you receive here or from your dealer are just a starting point.  Don't get too hung up on a formula of X teaspoons/use.  You need to find the amount that is enough chlorine to wipe out the stuff left behind after a use, plus leave a residual to fight off anything that may try to grow inbetween.  That varies with tub size, water chemistry, contaminants introduced, and more.    

It appears that part of the problem may be the time between uses, and therefore doses.  You may need to add chlorine every day, or at least every other -- whether you use it or not .  The ideal program would maintain a residual that drops to "barely measurable" right before you get in the tub the next time.  That is much easier to do with regular small doses than large ones every few days.  As another poster identified, the dose needed may also change over the life of the water change.  

The other thing to consider is your pH levels.  It is my understanding that chlorine is a much more effective sanitizer at a pH of 7.2 than it is at 7.8.  If your pH is a little high, that may explain why it is taking more chlorine to keep things in check.