Hot Tub Forum
Original => Hot Tub Forum => Topic started by: tileman on October 31, 2006, 05:54:02 pm
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How can my alkalinity be low while my ph is high? I thought they rose and fell together. :-?
Chad
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Not to be annoying, but can someone please help. :'(
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Was your initial water chemistry that way?
Your PH can be adjusted high by using soda ash and it won't affect the PH too much. You can use baking soda to raise PH and alkalinity and after a PH of 8.4 (the PH of baking soda) the PH won't be affected.
Alkalinity and PH are not the same! People think they are but alkalinity is what makes the PH stay steady.
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I was hoping you'd chime in. :) :)
Yes that's how it's been from the beginning. Ph was about 8.0 and Alk was about 70-80.
Since last night I have added spa down 3 times at 1.5 tsp doses. My ph is now at about 7.8 and alk has pretty much stayed the same.
Where can I get soda ash? That seems to be the only thing left out of my LT kit. Figures, since thats the one I need. :)
I've been using test strips for about 24 hrs now and already hate them. I just don't see how they can be that accurate.
From other posts of yours, I understand that the most accurate results for you come from the Taylor k-2005 kit. I think that is more my style as I seem to be a bit of a perfectionist myself. Where do you get yours at?
Thanks Vinny,
Chad
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I got mine from Doc.
You don't need soda ash at this point but you can also buy it from Doc. Soda ash raises PH. I also have bought supplies from big box stores (PH down needed ASAP due to a slip up in baking soda) and Leslies pools but feel the need to support Doc for the help he has given me through his site. Actually he has really good prices on all his stuff.
Since your PH is 7.8, leave it alone and see where it goes. PH tends to drift down with use then just add baking soda and you should be fine. What you're looking for not to happen is the PH go from one number to a lower number within a day or so. That's an indication that your alkalinity is too low.
I usually wait for my PH to get to 7.2 then use baking soda and bring it up to about 7.8. I usually scub the waterline with the baking soda and I kill 2 birds with 1 stone... raise alkalinity and PH AND clean the tub! :)
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Thanks Vinny.
So should I add some baking soda now, to get my Alk in range or wait due to my 7.8 ph.
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Since your PH is 7.8, leave it alone and see where it goes. PH tends to drift down with use then just add baking soda and you should be fine. What you're looking for not to happen is the PH go from one number to a lower number within a day or so. That's an indication that your alkalinity is too low.
Vinny,
Just to throw a curveball,
We tend to see the exact opposite, pH will creep up over time while alkalinity will drop. I have found it easier to drop the pH to about 6.8 and then raise the alkalinity and pH back uo together
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Since your PH is 7.8, leave it alone and see where it goes. PH tends to drift down with use then just add baking soda and you should be fine. What you're looking for not to happen is the PH go from one number to a lower number within a day or so. That's an indication that your alkalinity is too low.
Vinny,
Just to throw a curveball,
We tend to see the exact opposite, pH will creep up over time while alkalinity will drop. I have found it easier to drop the pH to about 6.8 and then raise the alkalinity and pH back uo together
I will say that you know more about this than I do since I start with low alkalinity and low PH and my water drops. I just assumed that all water drops in PH as it's used.
tileman, give this a try!
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Since your PH is 7.8, leave it alone and see where it goes. PH tends to drift down with use then just add baking soda and you should be fine. What you're looking for not to happen is the PH go from one number to a lower number within a day or so. That's an indication that your alkalinity is too low.
Vinny,
Just to throw a curveball,
We tend to see the exact opposite, pH will creep up over time while alkalinity will drop. I have found it easier to drop the pH to about 6.8 and then raise the alkalinity and pH back uo together
I will say that you know more about this than I do since I start with low alkalinity and low PH and my water drops. I just assumed that all water drops in PH as it's used.
tileman, give this a try!
I have noticed that ph has a tendency to creep back to where it started. If your ph is high out of the tap you will probably have your ph creeping up over time. If your ph is low out of the tap you will probably have your ph creeping down over time.
With tileman's water naturally having a high ph and low alkaline, I would think it best for him to take his ph down to match his low alkaline then bring them up together. But take your time, don't try and do it all at once, watch and see how it drifts on its own.
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I will try that too, if it comes up again for me. For a while I had persistantly low alk with pH over 8. I would add baking soad to bring Alk up to 150 or so, then add acid to drop pH. It worked, but the other sounds intriguing too.
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I was just going to post on the same subject. Vinny as you may remember our water is almost exactly the same out of the tap. I get somewhere around 60-70 TA and 7.0 PH, Perfect right a bit of baking soad and wahla....perfect water. This has held true for 10-15 years of on and off tubs sitting in my yard.
Well I seem to have a new dilema, I bought a different brand re-agent test kit and started using it with this last fill (Sunday) Its a pool Shop Basic test kit. 13 bucks (I'm a cheapo) Well after all these years this kit is telling me my water started out at 50-60 TA and 7.8 PH.......huh?
I'm kinda wondering if different test kits as well as methods (strips) won't give us different results? We know strips are different I have tested several different kinds side by side and found the results to vary except in Chlorine. So now I am wondering if the re-agent kits also vary a bit?
Any input from the water Nazis out there????
Oh and tileman.....I'd wait, I am now also. My PH will drop over time and the low Alkalitity will create an even more unstable PH. Once my PH drops which it will because of cyanuric acid (a byproduct of dichlor) I will adjust with baking soda. I have found that 1 OZ of baking soda will raise TA about 10 PPM and raise PH about .1 While soda ash seems to leave TA almost along (just a slight increase) and raise PH about .2-.3 per 1/2 oz but I spose everyones water in different areas responds differently also?? Good stuff.
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Thanks for the insight guys.
I just got home from work and checked water. It was still 7.8 ph and 80 alk, even after I added 2 oz. of baking soda last night. I wonder whats going on. :-?
Should I keep adding baking soda or try to get my ph down?
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Btw, when I add a tsp of dichlor after use, my fc jumps to about 5ppm after 20 minutes. Then it's right back to zero 8 hrs later. Is this normal?
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Btw, when I add a tsp of dichlor after use, my fc jumps to about 5ppm after 20 minutes. Then it's right back to zero 8 hrs later. Is this normal?
That's what mine does, and I would offer that that's a good thing...
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I was just going to post on the same subject. Vinny as you may remember our water is almost exactly the same out of the tap. I get somewhere around 60-70 TA and 7.0 PH, Perfect right a bit of baking soad and wahla....perfect water. This has held true for 10-15 years of on and off tubs sitting in my yard.
Well I seem to have a new dilema, I bought a different brand re-agent test kit and started using it with this last fill (Sunday) Its a pool Shop Basic test kit. 13 bucks (I'm a cheapo) Well after all these years this kit is telling me my water started out at 50-60 TA and 7.8 PH.......huh?
I'm kinda wondering if different test kits as well as methods (strips) won't give us different results? We know strips are different I have tested several different kinds side by side and found the results to vary except in Chlorine. So now I am wondering if the re-agent kits also vary a bit?
Any input from the water Nazis out there????
Oh and tileman.....I'd wait, I am now also. My PH will drop over time and the low Alkalitity will create an even more unstable PH. Once my PH drops which it will because of cyanuric acid (a byproduct of dichlor) I will adjust with baking soda. I have found that 1 OZ of baking soda will raise TA about 10 PPM and raise PH about .1 While soda ash seems to leave TA almost along (just a slight increase) and raise PH about .2-.3 per 1/2 oz but I spose everyones water in different areas responds differently also?? Good stuff.
It could be the quality or the age of the reagents. I have noticed that when I had 2 different test kits (yes I had two ... I like to keep an el cheapo kit just in case I get some strange readings) the cheaper kit gave me different PH results - I trusted the Taylor since that's their specialty.
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I have noticed that ph has a tendency to creep back to where it started. If your ph is high out of the tap you will probably have your ph creeping up over time. If your ph is low out of the tap you will probably have your ph creeping down over time.
I'm not so sure I buy into this theory considering the chemistry. Of the sanitizers available (please correct if wrong), dichlor is the most benign re: pH with it's pH of 7.0. I use dichlor for sanitization and both dichlor or MPS (pH 3-4) for shocking. Out of the tap, pH is 7.5 for my water. After a water change, adding air and agitation causes the pH to jump to 8.0+. After initially adding dry acid to bring pH down to 7.8 or so, I find that pH will continue to drop, not rise. This makes sense considering that I am adding dichlor (pH 7.0) daily and either dichlor or MPS (pH 3-4) weekly to bi-weekly. After a while, soda ash is needed to bump pH back up. I would think that utilizing bromine would just exascerbate the problem since bromine is a bit more acidic than dichlor.
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I agree. My PH always creeps down. And as I stated it is a direct result of dichlor and MPS use. I used Bromine also for a while years back and the problem was exasperated