+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 58

Thread: A Theory About Rising pH in SWG Pools

Hybrid View

  1. #1
    KurtV is offline Registered+ Widget Weaver KurtV 0
    Join Date
    Dec 2004
    Location
    Mandeville, LA, USA.
    Posts
    418

    Default A Theory About Rising pH in SWG Pools

    Theory: SWGs are generally placed on higher-end pools that are more likely to have other high-end features such as water falls, sheer descents, laminar jets, fountains, and other sources of aeration. That aeration, rather than the SWG itself, is the cause of the rising pH (or at least a contributor).

    Discussion: We know, at least anecdotally, that many, but by no means all, SWG pool owners experience a constantly rising pH that has to be counteracted with acid. Most people seem to believe that there's a causal relationship between the SWG and the rising pH but I've never seen an explanation of why this might be so. Since not every SWG pool fights constantly rising pH, couldn't some other feature that's common on pools with SWGs actually be the cause? (Correllation is a long way from causation.) As we all know from Ben's Alkalinity Lowering Procedures, aeration of pool water will cause high pH to rise. Therefore, I theorize that the aerating features are a likely cause of rising pH. (I have no idea if such features are more common on SWG-equipped pools but it seems logical.)

    My (very limited) basis for this theory is that I also have a constantly rising pH in my pool but no SWG. I do, however, have a negative edge on my pool that I try to run daily and which provides a great deal of aeration. From the alkalinity education I've been receiving from Ben, Richard, and Evan, I know that the out-gassing this aeration induces certainly doesn't help my pH situation and may indeed account for much, if not all, of the pH rise I see. Do others with like water features, with or without SWGs, see the same kind of upward trend in pH?

    Discuss among yourselves (or ignore this if I'm all wet).

    By the way, I'm not looking for any help with my own situation here. It's manageable with 16 to 24 oz. of muriatic acid per day and I'm trying to collect a month's worth of good data before I ask.
    Last edited by KurtV; 08-16-2006 at 09:38 PM.

  2. #2
    Join Date
    Apr 2006
    Location
    Scottsdale, Arizona
    Posts
    526

    Default Re: A Theory About Rising pH in SWG Pools

    Quote Originally Posted by KurtV
    I'm not looking for any help with my own situation here. It's manageable with 16 to 24 oz. of muriatic acid per day and I'm trying to collect a month's worth of good data before I ask.

    thats a lot of acid .. I use that in a week. At most.

    I test weekly and could not imagine having to make sure I make it home to test and add chemicals daily..
    14'x31' kidney 21K gal IG plaster pool; SWCG (Saline Generating System's SGS Breeze); Pentair FNS Plus 48 DE DE filter; Whisperflow 1 HP pump; 8 hours hrs; kit purchased from Ben; utility water; summer: none; winter: none; PF:5.7

  3. #3
    gwrace1 is offline Registered+ Thread Analyst gwrace1 0
    Join Date
    Dec 2005
    Location
    South Central Texas
    Posts
    122

    Default Re: A Theory About Rising pH in SWG Pools

    I run my SWG on a 26000 gallon above ground pool. It does a great job of maintaining the chlorine level. However I do have to add acid once per week to keep PH under control. I do have two returns on the pool managed by a three way valve. One operates the Aqualumiator/fountain pool light and the other runs a PoolSkim ahead of the skimmer. I really don't have any aeration going other than when we rarely run the fountain to cool down the water.

    I've read somewhere of the chemical process that goes on that seems to explain the rise in PH. We are on a very alkaline south Texas well so all my fill water helps to contribute to that PH rise as well.

    33' Artesian Echo Canyon Ultra II round with 54" wall 26000 gallon capacity -- 1.5 HP 2 Speed Pump / Pentair 26" Sand Filter with Zeolite filter media
    Aquarite Salt Water Generator -- Complete aluminum deck with fence kit
    Aqualuminator with Fountain -- Solar Pool Lights
    Pool Pictures at the link below
    http://community.webshots.com/album/548241672nKeuyR

  4. #4
    chem geek is offline PF Supporter Whibble Konker chem geek 4 stars chem geek 4 stars chem geek 4 stars chem geek 4 stars
    Join Date
    Nov 2004
    Location
    California
    Age
    64
    Posts
    2,226

    Default Re: A Theory About Rising pH in SWG Pools

    Could y'all post your TA and pH numbers (your "target" pH you reach after adding acid and your "high" pH at the point you need to add acid). And also compare your readings against this chart. Though it is absolutely true that increased aeration will cause an increased outgassing of carbon dioxide and subsequent rise in pH (and therefore acid demand), it is also possible that some of you may be at too high a TA level anyway.

    The easiest solution, at any aeration rate, is to lower your TA so you get into the "green" range on the aforementioned chart (some can be in the "orange" range, but this is dependent on aeration). My coloring of the chart is just based on experience from users so far and is subject to change, which is why I'm interested in your results.

    Richard

  5. #5
    KurtV is offline Registered+ Widget Weaver KurtV 0
    Join Date
    Dec 2004
    Location
    Mandeville, LA, USA.
    Posts
    418

    Default Re: A Theory About Rising pH in SWG Pools

    Richard,
    I hadn't intended this thread to focus too specifically on my situation but here's the last three weeks or so of my testing (CYA 30 ppm and calcium hardness 220 ppm throughout this period, daytime water temperature between 89 and 92 deg F, about 2800 ppm salt but no SWG):

    Date pH Alk. Acid addition
    7/26 7.8 100 24 oz.
    7/27 7.4 100
    7/28 7.8 100 16 oz.
    7/29 7.7 100 16 oz.
    7/30 7.2 90 32 oz. (before testing)
    7/31 Vacation
    8/1 Vacation 16 oz.
    8/2 Vacation
    8/3 Vacation 16 oz.
    8/4 7.8 90 28 oz.
    8/5 7.6 80 16 oz.
    8/6 7.6 80 16 oz.
    8/7 7.4 80 8 oz.
    8/8 7.6 70 16 oz.
    8/9 7.6 70 16 oz.
    8/10 7.5 70 16 oz.
    8/11 7.3 70 8 oz.
    8/12 7.4 70 16 oz.
    8/13 7.6 70 16 oz.
    8/14 Work trip
    8/15 7.6 70 16 oz.
    8/16 7.6 70 24 oz.

    Sorry about the format, couldn't get it any better than this.
    Last edited by KurtV; 08-16-2006 at 11:21 PM.

  6. #6
    Join Date
    Apr 2006
    Location
    Scottsdale, Arizona
    Posts
    526

    Default Re: A Theory About Rising pH in SWG Pools

    3 days ago .. TA = 95. I add acid once a week and the pH is normaly around 7.8 ish when tested weekly. I don't test every time. just add based on past experience.
    14'x31' kidney 21K gal IG plaster pool; SWCG (Saline Generating System's SGS Breeze); Pentair FNS Plus 48 DE DE filter; Whisperflow 1 HP pump; 8 hours hrs; kit purchased from Ben; utility water; summer: none; winter: none; PF:5.7

  7. #7
    Join Date
    Dec 1969
    Posts
    216

    Default Re: A Theory About Rising pH in SWG Pools

    Kurt,

    Just for comparison & discussion, I have a waterfall and two spa jets (lots of bubbles). I pretty much turn the water fall on and the spa jets always put out some bubbles any time the pump is running. Both features can be independently shut off but we rarely do. I have three returns that are always pointed up as the wife likes the “ripples”. PH is consistently in the 7.5 range and Alk around 110. I may have added 16 oz. of muratic acid since April and I would believe that my pool is at least in the mid to upper realm of high aeration. 16K Fiberglass in ground pool, CH is 150, CYA 40 and FC stays between 2 and 5. I do have 3200 ppm of Salt, no SWC, 1 HP Superpump & DE filter.

    Dave

  8. #8
    KurtV is offline Registered+ Widget Weaver KurtV 0
    Join Date
    Dec 2004
    Location
    Mandeville, LA, USA.
    Posts
    418

    Default Re: A Theory About Rising pH in SWG Pools

    David,
    As that doesn't support my theory at all, we'll have to throw it out as a bogus data point.

    (Hey, it's just a theory.)

  9. #9
    KurtV is offline Registered+ Widget Weaver KurtV 0
    Join Date
    Dec 2004
    Location
    Mandeville, LA, USA.
    Posts
    418

    Default Re: A Theory About Rising pH in SWG Pools

    Richard,
    Updated data. I think the acid demad might be letting up a bit.

    Date pH Alk. Acid addition
    7/26 7.8 100 24 oz.
    7/27 7.4 100
    7/28 7.8 100 16 oz.
    7/29 7.7 100 16 oz.
    7/30 7.2 90 32 oz. (before testing)
    7/31 Vacation
    8/1 Vacation 16 oz.
    8/2 Vacation
    8/3 Vacation 16 oz.
    8/4 7.8 90 28 oz.
    8/5 7.6 80 16 oz.
    8/6 7.6 80 16 oz.
    8/7 7.4 80 8 oz.
    8/8 7.6 70 16 oz.
    8/9 7.6 70 16 oz.
    8/10 7.5 70 16 oz.
    8/11 7.3 70 8 oz.
    8/12 7.4 70 16 oz.
    8/13 7.6 70 16 oz.
    8/14 Work trip
    8/15 7.6 70 16 oz.
    8/16 7.6 70 24 oz.
    8/17 7.4 [IMG]file:///C:/DOCUME%7E1/CLV/LOCALS%7E1/Temp/moz-screenshot-2.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/CLV/LOCALS%7E1/Temp/moz-screenshot-3.jpg[/IMG]65 16 oz.
    8/18 7.4 60 8 oz.
    9/19 7.5 60 20 oz.
    8/20 7.2 60 8 oz.
    8/21 7.4 60 8 oz.

  10. #10
    chem geek is offline PF Supporter Whibble Konker chem geek 4 stars chem geek 4 stars chem geek 4 stars chem geek 4 stars
    Join Date
    Nov 2004
    Location
    California
    Age
    64
    Posts
    2,226

    Default Re: A Theory About Rising pH in SWG Pools

    Kurt,

    I'll bet that when you hit 50, if you let the pH rise to 7.5 then the continued rise from there will be slow (i.e. you could add acid when it hits 7.6 or 7.7). You could therefore make your pH "target range" 7.5-7.7 and not use too much acid. In fact, the general advice for people with low TA would be to have higher pH for better water balance though this technically is only necessary for grout/plaster/gunite pools. Anyway, thank you so much for keeping such good track of your numbers. It really helps in trying to figure these things out.

    By the way, if the TA is somewhat stuck on 60 and getting lowered too slowly, you can always just add some extra acid to get to a pH of 7.2 or below in order to accelerate the outgassing (i.e. Ben's alkalinity lowering technique), but if you have the time and just want to see how things slow down as TA gets lower, then measure on...

    Richard

+ Reply to Thread

Similar Threads

  1. PH keeps rising
    By Devon in forum Dealing with Alkalinity and Calcium
    Replies: 14
    Last Post: 11-01-2012, 02:44 PM
  2. Rising pH??
    By sabres07 in forum Testing and Adjusting Pool Water Chemistry
    Replies: 3
    Last Post: 08-24-2012, 10:30 PM
  3. CH rising?
    By DONNIE in forum Dealing with Alkalinity and Calcium
    Replies: 40
    Last Post: 02-16-2007, 12:47 AM
  4. Rising Ph?
    By court475 in forum Dealing with Alkalinity and Calcium
    Replies: 2
    Last Post: 08-15-2006, 07:23 PM
  5. New Guy Theory????
    By chemistrydropout in forum Using Chlorine and Chlorinating Chemicals
    Replies: 2
    Last Post: 07-31-2006, 11:41 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts