High Acid Use

[chem geek]

The faster pH rise started with the addition of the SWG. Part of this pH rise may be from the increased aeration and part may be from chlorine outgassing. Is there a fairly short run of pipe from the SWG to the return(s) in the pool? You might try pointing your returns downwards (or diagonally down and to the side) to see if that gives the chlorine more time to dissolve into the water (if that's what is going on).

 

[frankgh]

It's w-a-a-a-y above my pay grade but can a condition exist within the plaster where it never really cures (or cures abnormally slow) so is constantly throwing off calcium and creating a pH rise?

How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?

So if there has been no fill water added, no features to dissolve and rain water generally does not add calcium (it can raise PH though), then the only possibility is the pool surface dissolving which is not a good situation.

That is what I was thinking. What now?

 

[PaulR]

New numbers for today

PH 7.8
TA 50
CH 550
Free CL 4.8
CC .2
CYA 60
Borates 30
Salt 3000

... CH has gone up from 2 months ago, it was right at 380 for the longest time so I have not been checking it. It is now 550. I checked it twice. Yes, it is a TF test kit and Apollo stirrer.

I know you redid it but it's still very suspicious that the CH jumped that much so fast. I haven't tried the stirrer, I know it's supposed to make the CH test go faster, but how much? How fast did you add the drops? If it was pretty quickly, maybe try the test again and wait longer between each drop.

That's incidental to the original question, of course, which is why does the pH go up so fast.

You're measuring the pH using the K-1000 kit that came with the TF100? Using R-0014 pH reagent (not R-0004)?
--paulr
who is grasping at straws just like everybody else

 

[dmanb2b]

The issue with that test is that the R-0009 reagent (and only that reagent) has a tendency to develop a static charge between itself and the bottle that contains it.

The result is that the drops "leap" from the bottle before they are fully formed.....causing the drops to be smaller. The result is a false high test result.

Sorry Dave, I guess I had that backwards...I never experienced the issue and was trying to quote from memory.

 

[frankgh]

I'm pretty confident in the CH number, it has come out the same 3 times with 2 differant sets of reagent. As far has ph, I have mesured it with a taylor kit, the taylor kit with the TF100 kit and a Hanna PH meter that was 2 point caled. All 3 agree with each other.

 

[polyvue]

I'm pretty confident in the CH number, it has come out the same 3 times with 2 differant sets of reagent.

It's been day or two. Have you tried anything else? Are your numbers the same?

 

[frankgh]

I didn't know I was out of acid and have been pretty busy and did not restock. PH last night was 8.2 off the Hanna meter. I will get it lowered today.

 

[frankgh]

Hi Folks,

I'm still dealing with this. Here is some fresh info and new issues:

Number today:

PH 8.0
FC 3.8
CC 0
TA 60
CH 600
CYA 60
Salt 3300
Borate 30

A week ago, I turned my SWG off and added some pucks to the off line feeder. PH is still climbing at the same rate even with a solar cover installed. No aeration or SWG.

And here is a new discovery that has me really happy, if you rub your hand on the pool walls, it gets cloudy where your hand was. Just briefly. And, I am finding very fine looking powder on the tiles on the steps. I brushed the walls down and the water clears back up very fast but WTF is going on???

If my 20 month old plaster is eroding, can it be stopped? Is it from the constant acid introduction? I am about to do a complete drain and refill. HELP PLZ!!!

 

[mas985]

I had a very similar situation with my plaster at about the same time frame as yours. I think that this is just the very top layer of plaster dust that was not removed during the first few weeks of brushing that finally let loose. As long as the surface remains smooth underneath, you should be ok. Look at the surface up close. Does it now look a bit more crystalline and mottled? Overall, has the look of the pool changed slightly going from pure white to a bit more mottled?

This is what may be raising your TA as well.

 

[frankgh]

Yes there is a slight molting, very slight. So, I shoould not lose any sleep tonight or should I be out there draining right now?

 

[mas985]

You should be fine, just don't let TA get too much lower than 60. It might help to keep PH between 7.6-7.8. That should lower your acid use some. Higher calcium helps offset the lower TA but if TA keeps dropping, then you can use baking soda to raise it up some. You will need acid to bring the PH back down but TA doesn't drop as fast as PH so that should be ok.