Ph going up crazy in spa

[dumbcluck]

Whenever we use the spa my ph goes up like crazy. A bright magenta color that is off the charts. Also free chlorine level drops considerably, sometimes to zero.
I have 3 kids 6-11 who spend quite a bit of time in there and probably pee a lot in there even though they have been told not to.
I also have a swg that is currently set to 5% for spa mode and an intelliph acid dispenser that shuts off when in spa mode.
I have 3" pipe running to the spa jets (8) and drains.
I have tried lowering the ph to around 7.2 just before turning on spa to compensate but doesn't appear to work.
Any thoughts, ideas?
TA has been pretty steady at about 110 since initial fill and water balance. New construction, first water in November 2014. I have attempted to bring TA down a few times but it seems to stay where it is.

 

[Richard320]

With the high TA and all the aeration the spa gets, pH is going to climb. Your problem is aggravated by the fresh plaster, driving pH and TA up constantly. I'd get aggressive with the TA and let the spa churn violently and overflow into the pool and keep lowering pH to 7.2 every couple hours until the TA is down to 70 or so. The spa pH will probably still rise a bit, but not as high or as fast. Lower TA How-to.

 

[dumbcluck]

Sounds like a plan. I'll give that a shot.
Thanks.

 

[dumbcluck]

Is there any other reason ph would go up so much?
It was about 7.5 last night and today is off the charts again. A deep magenta color. Spa only.

 

[jblizzle]

What is the FC?

 

[dumbcluck]

FC in the spa when I'm getting these high readings is always very low. Once it appeared as if there was zero chlorine. Usually the yellow is very light like maybe 1 or 2.
With my automation the swg is at 5% for the spa and the acid dispenser doesn't dispense in spa mode.
Spa is currently set to spillover for 45 minutes each day where the 2 bodies of water mix together.
Usually when I leave it alone at night (after pump time) the FC is 4or5 and ph is 7.5 or so at last reading. The pump then comes on again for 2hours from 2-4 am pool only.

 

[jblizzle]

ok now I am confused. The pH in the pool and spa should basically be the same if you are mixing the water.

When in spa mode, the pH is going to rise in the spa due to all the aeration.

 

[dumbcluck]

That makes 2 of us Jason.
I agree with everything you said.
The 2 are basically the same readings at night but not even close the next day.
I will experiment some more but am scratching my head now.

 

[jblizzle]

Well, I actually do not see anything surprising here. Seems like you are saying the pH rises a lot in the spa when you use the spa. That is expected.

You might want to consider running in spillover mode a bit more, add a short period during the night run.

 

[dumbcluck]

I'll check again tonight when I get home but yesterday it rose without using the spa. That's why I'm confused.
I'm going to add some spillover time at night too but that would mean more aeration.

 

[jblizzle]

Are you saying that when you are in pool mode or spillover mode (and NOT in spa mode for some time) that the pH in the spa is higher than the pH in the pool?

 

[dumbcluck]

Yes.
Just got home and checked it again. Off the charts.
Spa has not been on or spillover.
Was at around 7.4 last night when pump went off.
Pool is still 7.4

 

[dumbcluck]

Same thing again today.
How is this possible?
Is it my plaster?
It's the same age as the pool which is fine.
Any thoughts?

 

[dumbcluck]

Still happening. Ph going up like crazy overnight. No jets or spillover.
It's gotta be something about the plaster right?
Anybody experience something like this?

 

[wjr75]

I went through about 6 gallons of muriatic acid last year after our replaster. I would check and add ever morning and make sure you run your overflow to mix the pool water with the spa.

 

[dumbcluck]

To my knowledge the problem is new. It is only in the spa. The pool which was plastered at the same time has no issue.
I wasn't testing the 2 seperatly the while time but have occasionally in the past and hadn't noticed any difference.
My kids do use the spa more often than the pool. Is it possible that it somehow got out of control before I noticed it and am now seeing the aftermath?

 

[wjr75]

I'm not the spa expert but it sounds to me your not getting enough turnover of spa water to the pool. My jandy valve is 50% to pool 50% to spa when on regular filtering.

 

[dumbcluck]

So you do both at the same time?
Mine is set to spillover 45 minutes each day.
Does it seem normal for the ph to rise so much overnight? It only increases in spa.

 

[wjr75]

Mine spills over all the time when the pool is on. I also have mine programed to just go to spa mode for 15 minutes each day to filter the spa and flush the filter pipes with fresh chlorine. I also run the spa jets for 5 minutes and the blower for one minute to flush the pipes. I don't think you are getting enough turn over in the spa for the new plaster.

 

[dumbcluck]

Something to think about...