PH bounces high

[smackman]

WHEN I get my HT back in service, I always have issues with PH bouncing high. My tap water is at lest 8.2. I drop it to 7.5; when we get in and out of HT it will be at 8.2 again. This is a fight I have for several weeks.

My Alkalinity at start up is generally around 150 -180 ppm. Is this my problem? I use HTH PH decreaser and Bromine for the sanitizer. Bromine should eventually keep the ph down but I very seldom fight Low PH even after 2 months of usage 4 days a week.

Help with this is appreciated. I do not worry about it because I treat a Hot Tub as A big Bath tub meaning I can easily change the water if I need to. I generally do after 6 weeks

[Chas]

I tell folks to wait at least five or six hours before retesting. Do you wait that long? I generally have a five-hundred gallon tub and our tap water is 8.0 (usually). I put in four ounces of "Spa Down" while the water is cold, then wait six (ish) hours until it is hot. Then I test, and add three or four more ounces, and add my dichlor.

The following day, a test will reveal if I need the last ounce of spa down or not. This works every time - the only variable is that last ounce.

Our water tends to creep up in pH, so I toss in an ounce now and then, mostly in line with how much jet usage (aeration) the water gets.

Also - test strips will not give you a reliable pH reading if your chlorine level is over about 3ppm. Don't even bother if it higher than that.

HTH

[smackman]

I use Bromine and a HTH kit. Yeah, I learned the hard way about high bromine levels and test strips.

I use the granular HTH PH Down. It generally takes at least 6 big teaspoons to get the PH to move. I generally start adjusting after I reach 80 degrees but I have not waited 5 hours and checked again.

Thanks for the advice. I will try your method. I always struggle with high PH  even 30 days later. My tap water ph is very high and really soft; Foaming can be a issue also because of the calcium hardness level being less than 100 out of the tap

[TwinCitiesHotSpring]

your Alk. is too high...Alk. is a buffer for pH so if your Alk. is not at proper levels your pH will always "bounce"....based on another post you said you had a J-465, based on the gallons in that spa you are looking at approx. 6oz. (based on rough calculation in my head) of "spa down" to get that Alk. into the perfect range....I would dilute it and split it into 2 additions 1. dilute 3oz. in warm water, pour it in, let circulate for a min. or two 2. run jets for 15 minutes to aerate pH back up 3. dilute second 3oz. addition and pour in and let circulate again for a few minutes, then run jets again for another 15-20min.....and BOOM your set :-)

[smackman]

Thanks; I will have to but some Alkalinity down. Here is a stupid question; Will PH downeventually bring the Alkalinity down?

[TwinCitiesHotSpring]

Thanks; I will have to but some Alkalinity down. Here is a stupid question; Will PH downeventually bring the Alkalinity down?

yes...pH down aka Sodium Bisulfate is a dry acid and will lower both Alk. and pH...which is why its a good idea to run your jets in between large doses in order to raise your pH back up when attempting to adjust your Alk. only