Shock: MPS or Dichlor?

[HotTubMan]

Hello Steve771;

35 grams or 1 tablethingy should do it provided you do not have a free/total chlorine variance greater than 1PPM. Basically you would need 1 tablespoon/1PPM vartiance between total and availible chlorine. Hope this helps.

HotTubMan

[steve771]

Thanks HotTubMan, I'll give that a shot.  I suppose this sounds stupid, but how long should chlorine show up in the system?  Is that 1ppm a constant (or a desired constant)?  Mine seems to drop off between uses (which is once a day, and right after getting out, I throw a tsp of dichlor in).

Also, my Ph is running high (not super high, but at the very top of the range).  I tried bringing it down with the envelope of "spa down" from Leisure Time that came with the chem kit, but it stays up.  Any suggestions there on what to use?  Thanks!  

[HotTubMan]

Thanks HotTubMan, I'll give that a shot.  I suppose this sounds stupid, but how long should chlorine show up in the system?  Is that 1ppm a constant (or a desired constant)?  Mine seems to drop off between uses (which is once a day, and right after getting out, I throw a tsp of dichlor in).

Also, my Ph is running high (not super high, but at the very top of the range).  I tried bringing it down with the envelope of "spa down" from Leisure Time that came with the chem kit, but it stays up.  Any suggestions there on what to use?  Thanks!  

Perhaps you misunderstood. If you are just using chlorine to sanitize, maintain a 3-5PPM of cl. I was suggesting that a tablespoon would oxidize your water adequately if there is a 1PPM variance between toatl cl and availible cl. Maybe you did understand, just want to make sure.

High PH is common in tubs, especially with high jet counts. If your tub is running filter cycles with a massage pump (as opposed to a circ pump) and you have your venturi air valves open, your pH will rise. I always recommend that customers turn air valves off after use and also to leave diverters in the centre/split position as much as possible. The reason for the diverters is to ensure circulation through ALL of the plumbing regularly. I have had customers leave diverters in one position for a long time, this can result in a nasty mould in the stagnent plumbing.

There may be many causes for the high pH besides airation and bathers. How is tha TA? high TA will drag up your pH.

HotTubMan

[Warkovision]

The reason for the diverters is to ensure circulation through ALL of the plumbing regularly. I have had customers leave diverters in one position for a long time, this can result in a nasty mould in the stagnent plumbing.

Interesting HTM. I never thought of that. We have one diverter setting that works the best for us. Will turn the diverters so that all the plumbing is involved when sanitizing. Thanks

[steve771]

Ok, gotcha on the variance vs. constant.  But is "constant" really constant as in continual?  Doesn't chlorine dissapate over time?  Should you take a reading 10-15 minutes after adding and go by that?  And I'm assuming after a shock, one needs to wait until the chlorine tests in that range, and that would vary by tub size in how long it takes?

Ref. my TA, it is also high, about 130-140 ppm.  I figured that might be causing my Ph problem.  What would you suggest to bring the TA and Ph into the proper range?

[HotTubMan]

Ok, gotcha on the variance vs. constant.  But is "constant" really constant as in continual?  Doesn't chlorine dissapate over time?  Should you take a reading 10-15 minutes after adding and go by that?  And I'm assuming after a shock, one needs to wait until the chlorine tests in that range, and that would vary by tub size in how long it takes?

Ref. my TA, it is also high, about 130-140 ppm.  I figured that might be causing my Ph problem.  What would you suggest to bring the TA and Ph into the proper range?

Your "spa down" is used to lower both TA and pH. Unfortunately adding a quantity of spa down to lower your TA in one shot would lowewr your pH to a dangerously low level. Therefore you lower your TA by adding some (TBSP+) spa down each day for 2-4 days. Once TA is in line you will be able to manage your pH much easier.

As for the clorine after shocking, one hour with the cover off is fine.

Your cl will dissapear even when you are not using the tub. This means its killing something.

HTM

[steve771]

Thanks for the guidance.  That info on the TA vs. the Ph is really helpful.  My original TA was higher, and I did add some Spa Down to get it where it is.  However, I was a little concerned that the Ph wasn't really dropping.  Now I understand how they interact and will keep at it.  (it's really nice to know I'm on the right track!  )

I did notice that some recommendations call for TA of 80-100 (like on my test strips) and others call for it as high as 130 (like in my manual).  Seems like quite a bit of variation!

[HotTubMan]

I have worked at two stores that used different parameters for TA. The first was 125-150, the second was 80-120. I feel that 80-120 is more effective in a spa or concretepool while 125-150 is more effective for a vinyl pool. I found my customers at the first store constanly had high pH and low TA. At the second store TA and pH require less adjustments.

MyTwoCents

HTM

[poolboy34]

Here's a trick for raising and/or lowering your TA.  If your tub has a "stand - by" mode, put your tub on stand - by (this shuts off the crc. pump).  Once your jets and circ pump have been off for 10 mins, add the appropriate ammount of Alkalinity increaser or pH down into one spot in the middle of the spa.  After 10 mins (take the spa out of stand-by mode) turn the jets on high, and let the spa run for 30 mins.  This will increase/decrease the TA w/o effecting the pH all that much.

As for the parameters of TA and pH.  If you shock with MPS on a regular basis or if you use Nature 2 / D-1's Vision Cart. you might want to keep the TA a lil higher.  The reason for this is that the MPS will bring the TA down over time.  Also Nature 2 / Vision has a pH of 7.9, keeping the TA higher will help stabilize the pH and prevent "pH creep."  Just my two cents.

Jason,
Store Manager for a D-1 & Caldera Spas Dealer

[steve771]

Why does it matter how you add the pH down?  I thought the wait period was for it to dissolve in the water.  If you pre-dissolve it in a bucket, does this have the same effect?  

[ttodd1]

"When adding chemicals you normally run some jets so the chemicals can mix in the water with one exception and that is any PH Decrease product. With any PH Decrease product it is best just to add it to the water and wait about 30 minutes before turning on jets. The reason for this is that because adding an acid to your spa if it gets directly into your pumps or heater it could cause some damage. That is why we try to maintain our PH above 7.2"

From the FAQ at "that other site".

[steve771]

Yup, I read that too, but if you dissolve the crystals in water first, does that still hold true?  

[bulmer4nc]

"When adding chemicals you normally run some jets so the chemicals can mix in the water with one exception and that is any PH Decrease product. With any PH Decrease product it is best just to add it to the water and wait about 30 minutes before turning on jets. The reason for this is that because adding an acid to your spa if it gets directly into your pumps or heater it could cause some damage. That is why we try to maintain our PH above 7.2"

From the FAQ at "that other site".

Does this hold true for liquid Spa Down too?

[salesdvl]

The "trick" Jason described is what we call "slugging".  It can be done in swimming pools too.  The water needs to be at a dead calm so I always tell customers to wait a couple of hours before and after.  When you pour in the acid, try to pour slow as if filling a jar just below the surface. You dont want to broadcast.  I am told that if the water is clear you can actually see particles moving toward the acid concentration.  If you stir it too soon that would be a bad acid trip and just lower your PH.   Dude.

[ttodd1]

Yup, I read that too, but if you dissolve the crystals in water first, does that still hold true?  

The way I read it  - yes.