Alkalinity 60, PH 8.0, Calcium 230

[Gomboman]

My water out of the tap is low in alkalinity and high in PH. It usually takes a couple of weeks to settle down. Even after I get the water balanced, it tends to go back to where it started--out of phase. I changed my water out three weeks ago and just got my water tested at my local pool store--my dealer doesn't test water. They used a professional Taylor test kit by the way.  

Anyway, here are the readings: Alk 60, PH 8.0, Calcium 230. I know I need to first address my alkalinity first and then tackle the PH. My question is, should I use my PH/Alk Up product (Sodium Hydrogen Carbonate) or baking soda (Sodium Bicarbonate)? I've heard people say that Baking soda will tend to raise the alkalinity without affecting the PH as much as using Sodium Hydrogen Carbonate. Is this true?

Does anyone have any special advise for me since my Alkalinity and PH are out of phase? Should I try to raise my Alkalinity to the high side of the specification since I will have to eventually lower my PH and the Alkalinity will drop also? I try not to micro manage my water but it is difficult to balance. I'm using dichlor, ozone, and N2 by the way.

[windsurfdog]

Gombo,

I'd concentrate on the pH and let the TA go for now.  If you haven't read this thread, give it a whirl:
Some alternative ideas re: dropping pH
Once you get pH down to 7.0 or so, you could then use baking soda to raise both pH and TA.  If you use dry acid to drop pH it will also drop TA but with MPS you may be able to drop pH without affecting TA much.  Might be worth a shot.

[HotTubMan]

I am not saying that WSD is wrong, I never argue with good results.

My trainig and experience says that you should use the bicarbonate to correct the TA, wait 2 or more hours and then correct the pH.

[windsurfdog]

My trainig and experience says that you should use the bicarbonate to correct the TA, wait 2 or more hours and then correct the pH.

I was under the impression that using sodium bicarbonate would raise both TA and pH.  Then if using dry acid (sodium bisulfate) to treat pH, it would also drop TA.  If this is the case, seems that a "tail chase" would ensue.  I guess that's why I recommended ignoring TA and using MPS to both drop pH and shock.  My training re:  water chemistry is nil and my experience is limited so I appreciate your insights, HTM.

[Brewman]

Sodium bircarbonate raises alkalinity with only a very minor increase in ph.  In Gomboman's case, he can probably raise his alk to the desired level, and probably not notice a ph change.

[HotTubMan]

For every 40 grams of bicarbonate, 1 gram of acid to nulify the effect on pH.

[In_Too_Long]

Your TA is your buffer for your pH. Get your TA in line first.
Your TA is like your shocks on your car, and your pH is your car. If your shocks are low your car bounces, if your TA is low your pH bounces. One time you test it it's high, next time it maybe low. If your TA is high your pH will stay high.
Your calcium isgood at 230, i keep my calcium 3 times higher than my TA and my water stays blue. Your calcium also has a similar effect as a buffer to your TA.

[Gomboman]

Wow, thanks for all the great advice.  I like the analogy with the car. OK, it sounds like I should use Bicarbonate to raise my Alkalinity instead of Sodium Hydrogen Carbonate because it doesn't affect my PH as much?  

With a 450 Gal. spa, how much Bicarbonate should I use to raise my Alk. from 60?  Should I baby it up?  I usually add an ounce at a time.  Should I shoot for the high end of the specification of 125-150 (ppm)? Also, once my Alkalinity is in order, should I wait a day or two before adjusting my PH?

For every 40 grams of bicarbonate, 1 gram of acid to nulify the effect on pH.

[HotTubMan]

153 Grams (5 ounces) should get you to 150. I would go with 3-4 ounces, especially if you are using test strips.

Wait an hour or two, then adjust your pH.

Also, unless you are using neutralizer in your testing, be careful when your br/cl is high, it messes with your TA and pH tests.