help! low TA high PH

[apple]

My PH was at 7.9 and my TA was at 40.  I put in PH down and now my readings are PH 7.5 and TA 33.  What should I do to raise the TA and not the PH?

[Chad]

Add Baking Soda in one TBS increments until alk is at a level where your pH remains constant. Don't worry about how high or low your alk is as long as pH remains steady.

I usually wait a day between doses.

[drewstar]

Add Baking Soda in one TBS increments until alk is at a level where your pH remains constant. Don't worry about how high or low your alk is as long as pH remains steady.

I usually wait a day between doses.

Soon you will need a photo id to balance your water.

Man, some lawmakers are idoits:

http://www.kmov.com/localnews/stories/kmov_localnews_070405_bakingsoda.3618f4f3.html

[Richs100]

Soon you will need a photo id to balance your water.
Man, some lawmakers are idoits

Well, on that note, I'm off for a friday night soak.  
Guess I'll leave the wine in the bottle and just snort some baking soda while I can still get it OTC.

BTW, what are my body's pH and Alk supposed to be?  
I don't want to do too much, cause that Spa Down stuff is harsh!
 

[Chad]

Soon you will need a photo id to balance your water.

Man, some lawmakers are idoits:

http://www.kmov.com/localnews/stories/kmov_localnews_070405_bakingsoda.3618f4f3.html

Thanks for the link Drewster.
Do you read our local news often?
I can't believe they actually think that will help with the drug problems here in the STL. :-/   What a bunch of idiots.

[Micah]

Add Baking Soda in one TBS increments until alk is at a level where your pH remains constant.
I usually wait a day between doses.

Some of the better chemical companies no longer use sodium bi-carbonate (baking soda) as a total alkalinity increaser.  The problem is that it raises the ph as well as the t/a.  Spend just a couple bucks more and it will make your life much easier

Don't worry about how high or low your alk is as long as pH remains steady.

If your ph is 7.5 and your T/A is 40, then your water is acidic.  This is one of the quickest ways to find out how much a new heater is going to cost you.

[Reese]

Some of the better chemical companies no longer use sodium carbonate (baking soda) as a total alkalinity increaser.  The problem is that it raises the ph as well as the t/a.  Spend just a couple bucks more and it will make your life much easier

If your ph is 7.5 and your T/A is 40, then your water is acidic.  This is one of the quickest ways to find out how much a new heater is going to cost you.

:-? Are you confusing sodium carbonate (soda ash/pH up) with sodium bicarbonate (baking soda/alk increaser)?  Although both raise pH and TA... the carbonate is a higher pH product and raises pH more than alk, while bicarb does the opposite.  What do you recommend for "a couple of bucks more"?

I also don't understand the statement that water with a pH of 7.5 is acidic.  7.0 is considered neutral, so please elaborate.

[Micah]

yes I forgot the "bi" in my carbonate
If you T/A is at 40 yes your water is corrosive and will damage your heater.  Even if your ph is high it will still damage your equipment
Try sodium hydrogen carbonate for one.

[Chad]

If you T/A is at 40 yes your water is corrosive and will damage your heater.  Even if your ph is high it will still damage your equipment

What is the scientific reasoning for this?
I still don't understand. I'm just curious as to what makes water so corrosive when pH is stabilized at 7.5 with a low alkalinity.

Thanks

[Micah]

What is the scientific reasoning for this?
I still don't understand. I'm just curious as to what makes water so corrosive when pH is stabilized at 7.5 with a low alkalinity.

Thanks

I'm not a scientist, (I just play one on the internet) It goes back to a scale called the saturation index.  The sum of 12 tests will determine if the water is corrosive or not.  To just look at the ph test is very much like a litmus test for the overal acidity of the water.  When dealing with a public spa or pool the health department requires documentation of T/A as well as PH.  If you only pay attention to the ph, you will most likely have chemical damage to your spa in a few years.

[Reese]

...Try sodium hydrogen carbonate for one.

That is sodium bicarbonate (baking soda).  Perhaps your "better chemical companies" just use that name so they can charge "a couple bucks more" for it.

[Reese]

...It goes back to a scale called the saturation index.  The sum of 12 tests will determine if the water is corrosive or not...

What are the 12 tests?  pH, TA, Hardness, and Temperature are commonly used to determine water balance... what else?  The "Saturation Index" refers to water's capacity to hold calcium in solution.  While balanced water can provide some protection by allowing a thin layer of calcium to form on sensitive components... it really is not an indication of the corrosiveness of the water itself.

I've never seen anything that would indicate that a pH of 7.5, TA of 40, and a reasonable hardness would lead to problems with anything other than a plaster/cement pool or a non-alloy heater.

[Micah]

That is sodium bicarbonate (baking soda).  Perhaps your "better chemical companies" just use that name so they can charge "a couple bucks more" for it.

Chemical make up according to NTSB:
NAHC03 = Sodium Bi-Carbonate
NAH2C03= Sodium Hydrogen Carbonate
Same family of chemicals but there is a slight differance.

[Reese]

Chemical make up according to NTSB:
NAHC03 = Sodium Bi-Carbonate
NAH2C03= Sodium Hydrogen Carbonate
Same family of chemicals but there is a slight differance.

I googled sodium hydrogen carbonate and only found references to sodium bicarbonate (to be fair, I only looked at the first page of listings). Can you direct us to your source of this info?  I tried the NTSB, but only found MSDS showing sodium hydrogen carbonate and sodium bicarbonate as the same thing.

It has been a long time since my college chemistry, but since Na+ and HCO3- balance out, it would appear that NaH2CO3 would have an extra hydrogen atom, making it unstable.  

[Micah]

Reese I have to admit that I didn't look that up.  I may have misquoted that formula.  I got that from the wholesale house that I purchase those items from.  They were the ones that explained it to me and showed me the diferences.  They are closed untill monday but I can ask for the documentation and post it then.
On another note, I am impressed that you can remember all that stuff from chemistry.  I can't for the life of me remember all those elements and formulas.