Hot Tub Forum

Original => Hot Tub Forum => Topic started by: kufferaths on September 11, 2005, 07:47:44 pm

Title: PH and Alkalinity
Post by: kufferaths on September 11, 2005, 07:47:44 pm
I have 400 gallons of water.  My Ph is at 7.8 and my Alk is at 70.  Is this acceptable or do I need to raise my Alk and lower my PH to 7.6?
Title: Re: PH and Alkalinity
Post by: fletch49 on September 11, 2005, 07:59:46 pm
your pH is fine, I would try to maintain your TA around 100-150.
Title: Re: PH and Alkalinity
Post by: kufferaths on September 12, 2005, 12:11:38 am
How do I raise my Alk without raising my PH?
Title: Re: PH and Alkalinity
Post by: Tman122 on September 12, 2005, 06:05:27 am
Quote
I have 400 gallons of water.  My Ph is at 7.8 and my Alk is at 70.  Is this acceptable or do I need to raise my Alk and lower my PH to 7.6?


That's the problem, it is very difficult to raise your TA and not affect your PH. I would leave those readings alone as time will change them anyway. By next week or the week after it may be different. If you find your PH moving around because your alk is a bit low it will most likely move down which is what you want. Once your PH has moved down a bit the sodium bicarbonate will raise both alk and PH together. Some dry acid will lower your PH and likely affect your ALK very little so you could try that but that's alot of work so I would just see what happens.
Title: Re: PH and Alkalinity
Post by: Brewman on September 12, 2005, 07:58:46 am
Sodium bicarbonate (Baking soda) will increase alkalinity without much affect on PH.
Title: Re: PH and Alkalinity
Post by: windsurfdog on September 12, 2005, 08:24:14 am
Quote
I have 400 gallons of water.  My Ph is at 7.8 and my Alk is at 70.  Is this acceptable or do I need to raise my Alk and lower my PH to 7.6?

In this case, just leave both settings alone for now.  If you are using dichlor, the pH will ever so slightly come down on its own.  If you are using unbuffered MPS for shock, the pH will come down a more quickly.  Once your pH is around 7.2 or so, use baking soda to raise both pH and TA as using soda ash will only affect pH.
Title: Re: PH and Alkalinity
Post by: CalicoskiesNC on September 12, 2005, 08:49:46 am
I use something called Alk Increaser by Baqua Spa, I think its the ingredient Brewman says.  It doesnt affect my pH much at all.  I keep my pH just a bit lower, like 7.6 and my alk at 110ish.  
Title: Re: PH and Alkalinity
Post by: Brewman on September 12, 2005, 09:40:30 am
If your Baqua Spa bottle say "Sodium Bicarbonate", then it's essentially baking soda.  
Really expensive baking soda.  
Title: Re: PH and Alkalinity
Post by: orlandoguy on September 12, 2005, 10:10:19 am
My alk also seems to drift down as my ph increases.

I use baking soda and sprinke around 4oz into the tub with the pump on low.  Is this what you guys do??
Title: Re: PH and Alkalinity
Post by: Brewman on September 12, 2005, 10:58:02 am
Pretty much, but I ususally go an ounce or so at a time.
Mine doesn't drift down too much.

I think the MPS shock I use is credited with the driftdown of my Ph and alk.  

Title: Re: PH and Alkalinity
Post by: orlandoguy on September 12, 2005, 11:57:21 am
I was thinking th MPS was the culprit too.  
Title: Re: PH and Alkalinity
Post by: jsimo7 on September 13, 2005, 10:40:53 am
Quote
If your Baqua Spa bottle say "Sodium Bicarbonate", then it's essentially baking soda.  
 Really expensive baking soda.  

Is Sodium Hydrogen Carbonate ( Bio Brand Total Alk Increase ) the same thing?  Baking Soda?
Title: Re: PH and Alkalinity
Post by: Brewman on September 13, 2005, 02:54:07 pm
Check this out:

http://scifun.chem.wisc.edu/chemweek/Bicarb/SodiumBicarb.html

Appears to me that they are the same.  But I'm not a scientist, nor have I played one on TV.  



Title: Re: PH and Alkalinity
Post by: tony on September 13, 2005, 04:37:44 pm
Baqua Alk Up (sodium hydrogen carbonate) is baking soda.  My TA tends to stay on the lower side of acceptable.  My pH stays pretty good.
Title: Re: PH and Alkalinity
Post by: devilwoman on September 17, 2005, 09:58:33 am
Quote
your pH is fine, I would try to maintain your TA around 100-150.


7.8 seems a little high...but I am new and learning.  I have read 7.2-7.6 is "ideal" whatever that means.  Mine is around 7.6-7.8 consistently and I thought that was nearing the high range.   Now I am trying to get my alkalinity corrected so as to not have this peanutbuttery scum stuff in my filter area.  I dont get any scum around the tub like a ring but I do in the filter reservoir.  I purchased an Artesian Dove Canyon tub about 2 months ago and am still trying to get the ph and alkalinity balanced.  

Just wondering is scum to some degree unavoidable?  And how much is normal?  I use ph down on a soft sponge to wipe down the sides of the filter reservior to get rid of the peanutbutter scum.  Anyway any ideas would be helpful.  Also I have read that Baking Soda will raise the Alkalinity without raising the ph.  So I am going to try that.  I am using SpaGuard softsoak system and I really like it...water is crystal clean and smells great and feels good, its just this scum (or whatever iot is that has me alittle worried).  Thanks!