Baking soda to raise pH + electric pH meters

[spa-ing]

Are there guidelines for how much baking soda is needed to raise the pH of a 400 gal tub? My pH seems a little low (maybe just around 7.2) and my alk is also low (40-80). I have pH up chemicals, but if baking soda does the trick, I'd rather use that.

--note it was all perfect until I added Spa Silken and the required dose of pH down (that threw it off--plus I used pool pH down which I guess was wrong although it was the same active ingredient in the same concentration as the pH down from the spa store)-- :-/

also, I've seen pH meters for sale for use with aquariums. This seems a lot more accurate than those test strips (mine never seem to be a color that is quite like the color on the strip). does anyone use one of those?

My spa water is otherwise clear, doesn't smell, no foam problems, etc etc, but I'm so worried about the numbers on those strips it makes me a bit nuts. Every day for a months I'm testing this thing for fear of creating some sort of viral soup!

My straight from the well water has high pH and high alk so everytime I top it off I'm hoping i'm raising the pH and the alk more to get it into perfect balance.

[twok99]

My tap water starts out at 40 ppm TA, and pH of 7.0-7.2.  I use Baking Soda to adjust my Total Alkalinity to 100-120 ppm, then add some Soda Ash to to bring my pH up to 7.5.  I find that the baking soda, does not adjust the pH enough.  I ususally have to add 1 Tbls of Soda Ash per week to bring my pH up (it tends to drop in my tub).  I am using dichlor to sanitize and shock.  I am using a Taylor test kit, which is a lot better than the test strips.

[Brewman]

Before going to a Ph meter, consider a liquid test kit- I find those easier to read than the strips.

Ph meters are rather expensive, require calibration with liquid samples, and need periodic probe replacement.  

I don't even mess with them with my brewing, where they'd be much more useful than for my spa.

[spa-ing]

Is the liquid test kit the Taylor Kit I read about?

[Brewman]

That is one brand, and it's very highly regarded among those who use it- from what I've seen it's very comprehensive.  It also costs upwards of $50- may well be worth it based on the rave reviews it gets.

There are other liquid test kits too- I've use one from Walmart that tests chlorine, Ph, alk, water hardness, and CYA.  That one costs closer to $15.

Spa and pool stores may carry other ones too.

[spa-ing]

i ended up putting in about 1T of baking soda. The numbers came in line and now it all reads really great. Glad I found the baking soda. Am still looking into the liquid test kit, but I think the strips are working great now that I've figured out what I'm doing.

[wmccall]

Are there guidelines for how much baking soda is needed to raise the pH of a 400 gal tub? My pH seems a little low (maybe just around 7.2) and my alk is also low (40-80). .

Rather than saying your PH is low, I would say its on the low end of the acceptable range. But the alk is definitely low, so concentrate on that one and see where the PH falls. They both should go up with baking soda.

On my 425 gallon tub I usually start with a ph of 7.0 and a similar alk reading.  I buy BS in one pound boxes and usually start with 1/4 of the box.  What ever you choose to start with, I recommend waiting another 24 hours to recheck it.  Nobody will die in the day or two it takes you get it dialed.