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Thread: Can ph minus be used for swg

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    Can ph minus be used for swg

    The thread entitled "TFPC for beginners" (authored by JasonLion) states that Dry Acid should not be used for a SWG. I have a digital Autopilot and my PB uses PH Minus (which I think is dry acid) all the time. PH Minus contains sodium bisulfate, and my SWG does indicate the addition of sodium bisulfate is acceptable to lower PH.

    Is there a reason that PH Minus should not be used with a SWG?

    Thanks
    1200 Sq Ft 41,000 Gal. Gunite, JANDY SVRS VS pump, JANDY JXI 400,000 BTU, Polaris 280 w/ 3/4 BP, Rockwall and Grotto (w/6 jets and blower), 2 JANDY Lam Jets, 2 LED Bubblers, 5 Ledlights, AQUALINK P16 RS, 90% Quartz, SWF 185 GMP BP, SWF 125 BP, Levelor K1100 Autofill, AP Digital SWG, 2 skim and 5 returns, and mostly 3 inch piping

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    Re: Can ph minus be used for swg

    Some SWCG manufacturers say not to use dry acid but others do not. Presumably they are worried about calcium sulfate scaling, but it takes an awful lot of sulfate for that to occur. More generally, we recommend against continued use of dry acid in plaster pools because in this situation there is the known concern for higher sulfate levels attacking concrete/plaster as described in Sulfates - what's the problem? and Sulfates why so bad?.
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    Re: Can ph minus be used for swg

    Well that creates a dilemma as my PB gives me the PH Minus for free, but I have to pay for the Muriatic acid. Are the fumes from the acid harmful? Do others use Acid Magic (which eliminates most fumes)?

    When you use the PH Minus, do you put it in the skimmer, or drop it near a return?

    Thanks
    1200 Sq Ft 41,000 Gal. Gunite, JANDY SVRS VS pump, JANDY JXI 400,000 BTU, Polaris 280 w/ 3/4 BP, Rockwall and Grotto (w/6 jets and blower), 2 JANDY Lam Jets, 2 LED Bubblers, 5 Ledlights, AQUALINK P16 RS, 90% Quartz, SWF 185 GMP BP, SWF 125 BP, Levelor K1100 Autofill, AP Digital SWG, 2 skim and 5 returns, and mostly 3 inch piping

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    Re: Can ph minus be used for swg

    That's odd, because dry acid usually costs more when you figure the volumes needed. The fumes can easily be avoided if you get some during additions, and if you add acid as some do, there are virtually none. Some members simple hold the jug by the handle, rest about half the jug in the water, and slowly tilt it until acid starts coming out slowly. If you do that very slowly at a return in your pool, there wil hardly be any fumes at all, and splashing/spilling potential is virtually Zero.
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    Re: Can ph minus be used for swg

    Thanks Patrick. I'll try that. The reason I get the PH Minus for free is because my PB supplies chemicals and that is just what they use. If I were to use some PH Minus, how and where should I put in the pool?

    I read some of the links posted above by Chem geek, but a lot of the embededed links are no longer valid. It seemed like PH Minus may cause problems for a plaster pool but the concentrations of Sulfates would have too be very high (and there wasnt much direct evidence on what such concentrations would need to be).
    1200 Sq Ft 41,000 Gal. Gunite, JANDY SVRS VS pump, JANDY JXI 400,000 BTU, Polaris 280 w/ 3/4 BP, Rockwall and Grotto (w/6 jets and blower), 2 JANDY Lam Jets, 2 LED Bubblers, 5 Ledlights, AQUALINK P16 RS, 90% Quartz, SWF 185 GMP BP, SWF 125 BP, Levelor K1100 Autofill, AP Digital SWG, 2 skim and 5 returns, and mostly 3 inch piping

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    Re: Can ph minus be used for swg

    I would not use it, but if I had too in a pinch, I would fill a five gallon bucket 1/2 full and add the acid to it and dissolve it. Pour that in very slowly in front a a return, and be very careful not to let it splash back on you or in your eyes. You could do the same thing I suggested with the jugs. Ask PB if they can get you MA at a discount. They should be able too for sure. I'd never use dry acid unless I was really in a bind to lower pH and had no other choice. I get four bottle cases at about 15.00+ tax from a pool builder supplier and he is still making money.
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    Re: Can ph minus be used for swg

    MA is also pretty cheap and doesn't take that much in my experience. plus it doesn't leave anything in the water that cant be removed (sulfates). don't be scared of muriatic acid, it isn't that bad. just use common sense and just pour it right in the pool like liquid chlorine. no pouring into measuring cups, etc...just eyeball it based on % of the jug. eliminates the issues.

    plus, I love having MA around the house. surprising how much you end up using the stuff when its on hand
    Dan
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    Re: Can ph minus be used for swg

    If you can find half-strength Muriatic Acid (15-16% Hydrochloric Acid) at roughly half-price, then that fumes a lot less than full-strength Muriatic Acid (31.45% Hydrochloric Acid).

    I updated the links so the few that were broken should no longer be broken (see this post). As noted in this link, the Pool Water Treatment Advisory Group recommends keeping sulfates below 300 mg/L. Every pound of dry acid in 10,000 gallons increases sulfates by 9.6 ppm. So 300 ppm sulfate would be after 31 pounds per 10,000 gallons if there were no water dilution. There may also be some sulfates in the fill water, but usually that's fairly low.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    Re: Can ph minus be used for swg

    Thanks. Appreciate it Chem geek
    1200 Sq Ft 41,000 Gal. Gunite, JANDY SVRS VS pump, JANDY JXI 400,000 BTU, Polaris 280 w/ 3/4 BP, Rockwall and Grotto (w/6 jets and blower), 2 JANDY Lam Jets, 2 LED Bubblers, 5 Ledlights, AQUALINK P16 RS, 90% Quartz, SWF 185 GMP BP, SWF 125 BP, Levelor K1100 Autofill, AP Digital SWG, 2 skim and 5 returns, and mostly 3 inch piping

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