Very High Ph

[Dietitian]

Is a very high PH corrosive, or just likely to leave mineral deposits? Could PH get so high as to damage metal/tile parts?

[Mark]

High PH can cause scaling which is the opposite of corrosive but it depends on the other levels; TA, CH, water temperature, TDS. You can use the poolcalculator.com to determine CSI which is an indication of scaling. The larger the CSI, the more likely the scaling.

[Dietitian]

High PH can cause scaling which is the opposite of corrosive but it depends on the other levels; TA, CH, water temperature, TDS. You can use the poolcalculator.com to determine CSI which is an indication of scaling. The larger the CSI, the more likely the scaling.

At some point the PH would be so high as to dissolve human flesh (lye will cause caustic burns)

Can it become high enough to dissolve hot tub materials?

[Mark]

Sorry, I thought you were talking about normal pool/spa conditions. Yes of course PH at the extremes of both ends will be corrosive to most metals. Given many chemical tanks are made out of fiberglass, that should hold up better than the metal but could still damage the surface. I think exposure time also plays a role. Are you planning an experiment or disposing of a body?

Recommendations from Dow:

http://www.dow.com/causticsoda/safety/material.htm

[Dietitian]

Sorry, I thought you were talking about normal pool/spa conditions. Yes of course PH at the extremes of both ends will be corrosive to most metals. Given many chemical tanks are made out of fiberglass, that should hold up better than the metal but could still damage the surface. I think exposure time also plays a role. Are you planning an experiment or disposing of a body?

Recommendations from Dow:

http://www.dow.com/causticsoda/safety/material.htm

My tub got up to PH 10.7 and I ran out of dry acid last night, wondering if 10.7 is damaging for an overnight stay in my tub : )

[polyvue]

Sorry, I thought you were talking about normal pool/spa conditions. Yes of course PH at the extremes of both ends will be corrosive to most metals. Given many chemical tanks are made out of fiberglass, that should hold up better than the metal but could still damage the surface. I think exposure time also plays a role. Are you planning an experiment or disposing of a body?

Recommendations from Dow:

http://www.dow.com/causticsoda/safety/material.htm

My tub got up to PH 10.7 and I ran out of dry acid last night, wondering if 10.7 is damaging for an overnight stay in my tub : )

Wow! Presume you're reporting the water in your spa and not some substance found on the fiberglass... how did you come up with a pH of 10.7? (what test or instrumentation)? If this is a meter, was it properly calibrated? That just seems too high to be accepted easily. You could ameliorate high pH in spa water by incorporating an acid ... including muriatic acid or weaker substances such as vinegar or lemon juice. But I would double check the measurement... and consider draining and refilling the spa after application, as well.

Do any of you other AG spa owners encounter pH levels this high?

[bart6453]

Sorry, I thought you were talking about normal pool/spa conditions. Yes of course PH at the extremes of both ends will be corrosive to most metals. Given many chemical tanks are made out of fiberglass, that should hold up better than the metal but could still damage the surface. I think exposure time also plays a role. Are you planning an experiment or disposing of a body?

Recommendations from Dow:

http://www.dow.com/causticsoda/safety/material.htm

My tub got up to PH 10.7 and I ran out of dry acid last night, wondering if 10.7 is damaging for an overnight stay in my tub : )

Wow! Presume you're reporting the water in your spa and not some substance found on the fiberglass... how did you come up with a pH of 10.7? (what test or instrumentation)? If this is a meter, was it properly calibrated? That just seems too high to be accepted easily. You could ameliorate high pH in spa water by incorporating an acid ... including muriatic acid or weaker substances such as vinegar or lemon juice. But I would double check the measurement... and consider draining and refilling the spa after application, as well.

Do any of you other AG spa owners encounter pH levels this high?

Holy...ph at 10.7??? That's about as high as ammonia.

You must have a misreading. How in the hell could it get that high?

Rarely does my ph get above 7.6

[Dietitian]

Holy...ph at 10.7??? That's about as high as ammonia.

You must have a misreading. How in the hell could it get that high?

Rarely does my ph get above 7.6

It was after a new fill -- my tap water is currently 9.5, and I accidentally had the air jets on, it climbed overnight....

I have an electronic meter that I calibrate every week. They're 50-100 bucks on amazon.

[chem geek]

I strongly suspect a testing equipment error. Aeration won't keep raising the pH forever. As the pH rises, there is less carbon dioxide in the water so that at a pH of 9.0 and a TA of 400 ppm the water is in equilibrium with the air. At a TA of 200 ppm, the equilibrium is reached when the water gets to a pH of 8.75 so I'll bet that your tap water reading of 9.5 is wrong (usually tap water isn't much above 8.0 and rarely above 8.5) as is your later 10.7 reading. It was probably more like 7.8 to start with and it rose to 8.5 or thereabouts. Do you know the TA level?

Try using a standard pH test as a comparison to see if your electronic meter is working properly. Do you hare a water quality report from your municipal water district and do they say the pH is that high?

[Dietitian]

I strongly suspect a testing equipment error. Aeration won't keep raising the pH forever. As the pH rises, there is less carbon dioxide in the water so that at a pH of 9.0 and a TA of 400 ppm the water is in equilibrium with the air. At a TA of 200 ppm, the equilibrium is reached when the water gets to a pH of 8.75 so I'll bet that your tap water reading of 9.5 is wrong (usually tap water isn't much above 8.0 and rarely above 8.5) as is your later 10.7 reading. It was probably more like 7.8 to start with and it rose to 8.5 or thereabouts. Do you know the TA level?

Try using a standard pH test as a comparison to see if your electronic meter is working properly. Do you hare a water quality report from your municipal water district and do they say the pH is that high?

The city does not include PH in their report. I have PH calibration fluid to calibrate the meter.

Here is the meter:

http://www.amazon.com/HM-Digital-PH-200-Wa...2944&sr=8-1

I'll test against a std color test to see if the calibration fluid is off.