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Thread: 29% acid vs 14% acid

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    29% acid vs 14% acid

    My local Lowes and Home Depot both carry muriatic acid (Kemtek) which is 14.5% HCl, and it's about $10 for two 1-gallon containers:

    http://imgur.com/WLzHEIO

    ...and now I just discovered a smaller local hardware store (Do-It Center) carries a different Kemtek box which is 29% HCI and it's also about $10 for two 1-gallon containers!

    http://imgur.com/RluHPuf

    But before I jump on this, I'm wondering about something. The first one says it contains 8.94 lbs of HCl per gallon. The second one (strangely) says it contains 9.56 lbs of HCl per gallon.

    Any chemists care to explain this to me? Is the second box double the strength of the first box (while being the same price)? Or is it only marginally more effective?

    Just wondering as I'm always looking for ways to save money. I know I could test this myself by measuring pH before/after using either version, but that'll take several days and I'm just wondering if anyone's got the answer off the top of their head.
    Los Angeles (San Fernando Valley)
    15k gallon in-ground (IG) pool (I believe it's plaster)
    DE filter (Heyward), using cellulose instead of DE
    Jandy APURE1400 3-port salt cell

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    Mike Hawk's Avatar
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    Re: 29% acid vs 14% acid

    My HD sells a cardboard box containing 2x1gallon 31% acid for $12.98 FWIW

    Brand: Smart
    Model # 2118 HD
    Internet # 100119310
    Store SKU # 346289
    http://www.homedepot.com/p/Smart-2x1...8-HD/100119310
    2007 Gunite 15k Pump: Whisperflo Motor: B2983 2spd 2.2/0.28 SFHP Sand Filter: TR100 SWG: Aqua Rite T15 Timer: PF1102T w/ redneck SPDT toggle switch Vacuum: Milliard 19" manual / PoolCleaner 2X auto

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    Re: 29% acid vs 14% acid

    I dont qualify or claim to be a chemist but I can answer your question.

    HCl (lower case L not an upper case I) is hydrogen chloride or hydrochloric acid. It is a gas dissolved in water that is called muriatic acid that lowers the pH. The more gas thats dissolved the stronger it will be.
    That is why 8.94 lbs of HCl per gallon is 14.5% and 9.56 lbs of HCl per gallon is 29% and yes 29% is double strength and your best deal.

    Have a look at pool math and it will show you 1/2 the dosage when you switch between the two:
    http://www.troublefreepool.com/calc.html

    And also you can figure which is the better deal:
    http://jfhtm350.webs.com/pool/Chemic...alculator.html
    And it appears the 29% is the better deal between yours and the 31.45% MHawk suggested.
    18,000 Gallon Aboveground. Sand Filter with 2HP 2 speed Pump.

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    Re: 29% acid vs 14% acid

    That was a typo -- its actually $10.98 for a 2 pack at Home Depot, and that's what I buy. Just don't store it indoors, in your garage, near chlorine or anywhere near anything that could potentially rust like pool equipment.
    14K Freeform Gunite w/60% Blue Quartz plaster, Quad DE filter, Intelliflo VS Pump + Booster for Cleaner, Aquacal Heat Pump

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    Re: 29% acid vs 14% acid

    My Home Depot has both 31% (labeled "Contractor Strength") and 14.5% (labeled "Pool") in 2-gallon boxes, often mixed together in the same stack, so have to pay attention to which I'm buying. The 31% contractor strength box is around $12, and the 14.5% pool box around $11, so it's clearly a better value to get the contractor strength -- but after accidentally buying the lower strength stuff, I found it a lot more pleasant to work with, much less fumes. So it's a tradeoff whether the premium for the lower strength is worth it, given the amount used isn't as high as bleach.
    21000gal IG plaster, Sacramento CA area (late 1950s/early 60s)
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    Re: 29% acid vs 14% acid

    jmastron, not sure what you're buying, but you're overpaying by a buck. the link above is correct, here it is again http://www.homedepot.com/p/Smart-2x1...8-HD/100119310 It costs the same no matter which home depot you buy it from, and it's outside with the pool stuff. It's the same as the "contractor strength", which is 31.45% 20 baum. Unless you're saying $12 after taxes, in which case that sounds about right.
    14K Freeform Gunite w/60% Blue Quartz plaster, Quad DE filter, Intelliflo VS Pump + Booster for Cleaner, Aquacal Heat Pump

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    Re: 29% acid vs 14% acid

    Sounds like Im overpaying. the 31.45 and 14.5 are both $7.29 for 1 gallon here at Lowes. No 2 gallon pack and no Home Depot close by which they are usually across the street from Lowes but not in this town.
    18,000 Gallon Aboveground. Sand Filter with 2HP 2 speed Pump.

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    Patrick_B's Avatar
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    Re: 29% acid vs 14% acid

    Quote Originally Posted by easttn View Post
    Sounds like Im overpaying. the 31.45 and 14.5 are both $7.29 for 1 gallon here at Lowes. No 2 gallon pack and no Home Depot close by which they are usually across the street from Lowes but not in this town.
    Indeed!

    31% runs about 8.00/Gallon here, but I buy mine from a local PB Supplier for 5.20...thanks to my PB who got me turned on to this. Next season, I plan on trying it in bulk-55 Drum and splitting it with my Pal. It's unbelievably cheaper that way.
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    MARCO...polo's Avatar
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    Re: 29% acid vs 14% acid

    Timely thread as I have been curious as to whether or not the big box stores in NorCal were only allowed to stock 14.5 as that is all I have seen locally. This doesn't include the products in the Paint Dept. From jmastron's post above I was surprised that Sacramento HD (60 miles to the NE) does stock 31.45. I recently got some 31.45 at one of the local Leslie's for $13.50/box ($6.75/gal)
    13,000 gal.Peanut shaped IG Plaster (med. gray) w/ 7' raised spa. ALL Pentair: Intelliflow 3hp VS, Cartridge filter, 400,000 btu heater, 2.0hp spa motor, Easy Touch control panel & is4 spa side switch, Intellichlor 40C SWG, Paramount PV3 In Floor cleaning system, spa spillway and two sheer descents. Solar: 10 FAFCO panels 1.5hp booster. Testt kits: K-2006 & K1766 (Chloride/Salt) Fill date August 15, 2114.

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    Re: 29% acid vs 14% acid

    Quote Originally Posted by zethacat View Post
    jmastron, not sure what you're buying, but you're overpaying by a buck. the link above is correct, here it is again http://www.homedepot.com/p/Smart-2x1...8-HD/100119310 It costs the same no matter which home depot you buy it from, and it's outside with the pool stuff. It's the same as the "contractor strength", which is 31.45% 20 baum. Unless you're saying $12 after taxes, in which case that sounds about right.
    Actually, the price does appear to vary -- if I "make my store" a Dallas store, the link above shows $10.98 for the 2x1-gallon (and the 14.5% pool stuff doesn't come up in a search), but if I set it back to my Sacramento store, the same link shows $11.98, with the 14.5% Kem-Tek box at $10.98. So I stand by my rounded prices, and am jealous of your better price

    Also, at least when I last bought acid (a month or so ago) the 31% I bought was Kem-Tek brand in a box (at the same $11.98 price as the Sacramento-link above), with "Contractor Strength" or "Pool" and the ingredient list being the only difference. I don't know if they had the "Smart" bottles elsewhere or if stores just stock equivalent commodity items without that feeding back to the web inventory. I'll take a picture of the mixed pile next time I'm there
    21000gal IG plaster, Sacramento CA area (late 1950s/early 60s)
    Filter: Cartridge, Pentair CCP420 (2014)
    Main pump: Pentair IntelliFlo VS (2015)
    Boost pump: 3/4hp (2011), Polaris 280 cleaner (unknown age)

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    Re: 29% acid vs 14% acid

    Quote Originally Posted by jmastron View Post
    Also, at least when I last bought acid (a month or so ago) the 31% I bought was Kem-Tek brand in a box (at the same $11.98 price as the Sacramento-link above), with "Contractor Strength" or "Pool" and the ingredient list being the only difference.
    Kem Tek Contractor Strength Muriatic Acid is 29%
    http://www.homedepot.com/catalog/pdf...8a5cc9a68f.pdf

    Kem Tek Muriatic Acid is 14.5%
    18,000 Gallon Aboveground. Sand Filter with 2HP 2 speed Pump.

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    Mod Squad jblizzle's Avatar
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    Re: 29% acid vs 14% acid

    This is the one thing I still buy at the pool store as it is 31% for the same price as the weak stuff from the box stores.
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    Re: 29% acid vs 14% acid

    Quote Originally Posted by easttn View Post
    Kem Tek Contractor Strength Muriatic Acid is 29%
    http://www.homedepot.com/catalog/pdf...8a5cc9a68f.pdf

    Kem Tek Muriatic Acid is 14.5%
    You're probably right; I was glossing over the difference between 29% and 31.45% as all "high strength", but it is 8%, potentially significant depending on price. Now I'm curious to see what's in my HD, will have to go check soon.

    And while I was annoyed when I realized I'd paid almost as much for the "low strength" 14.5% stuff, my other point remains that it was also more pleasant to use, so I might decide the few dollars a month difference is worth it. It goes against my careful spreadsheeting of all local chlorine prices and concentrations to save $2 a week though!
    21000gal IG plaster, Sacramento CA area (late 1950s/early 60s)
    Filter: Cartridge, Pentair CCP420 (2014)
    Main pump: Pentair IntelliFlo VS (2015)
    Boost pump: 3/4hp (2011), Polaris 280 cleaner (unknown age)

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    Re: 29% acid vs 14% acid

    Sorry to drag up an old thread, but this is what came up when I searched..

    So I was going to ask if anyone knew of a Better/Bulk price to get Muratic Acid. But I think I might have already paid the best price...

    I get 31% Muratic Acid at Menards for $3.99/Gal. Lowes and HD have 31.45% for $7.99/Gal.

    I was hoping to maybe find a bulk 3-5g, but have yet to find it available in bulk or cheaper than $3.99/Gal..

    -ThaChad
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    Re: 29% acid vs 14% acid

    Quote Originally Posted by ThaChad View Post
    Sorry to drag up an old thread, but this is what came up when I searched..

    So I was going to ask if anyone knew of a Better/Bulk price to get Muratic Acid. But I think I might have already paid the best price...

    I get 31% Muratic Acid at Menards for $3.99/Gal. Lowes and HD have 31.45% for $7.99/Gal.

    I was hoping to maybe find a bulk 3-5g, but have yet to find it available in bulk or cheaper than $3.99/Gal..

    -ThaChad
    Wrestling a 25-40 lb jug of acid sounds risky to me. Transferring it to a smaller container to pour just doubles the exposure and means you need an acid-proof spigot or pump. I'd stick with gallons.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: 29% acid vs 14% acid

    $3.99 is a great price for either concentration of muriatic acid. In my state (CA) they don't sell that high a concentration nor does it ever go down to that price.

    I'm the OP here, who was asking about 29% vs. 14%. Lately I've been buying 14% because the 29%, although more economical, is SO much more concentrated and I smell it a lot as I pour it, and I see the residue of the acid fizzle as it hits the pool, and I'm just thinking...this can't possibly be that healthy for me to breathe a bit of it and also have some of its vapors hitting my clothes.

    I'm not a chemist so maybe it's not that huge a deal, but I don't use a huge amount of acid so the difference in cost/efficiency isn't all that much to me. If it saves me $50 over the course of a year to use the higher concentration, I don't know that it's worth it.
    Los Angeles (San Fernando Valley)
    15k gallon in-ground (IG) pool (I believe it's plaster)
    DE filter (Heyward), using cellulose instead of DE
    Jandy APURE1400 3-port salt cell

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    Re: 29% acid vs 14% acid

    31.45% muriatic acid is the best for the price plus it saves space more chemical.

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    Richard320's Avatar
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    Re: 29% acid vs 14% acid

    Quote Originally Posted by ddas View Post
    $3.99 is a great price for either concentration of muriatic acid. In my state (CA) they don't sell that high a concentration nor does it ever go down to that price.

    I'm the OP here, who was asking about 29% vs. 14%. Lately I've been buying 14% because the 29%, although more economical, is SO much more concentrated and I smell it a lot as I pour it, and I see the residue of the acid fizzle as it hits the pool, and I'm just thinking...this can't possibly be that healthy for me to breathe a bit of it and also have some of its vapors hitting my clothes.

    I'm not a chemist so maybe it's not that huge a deal, but I don't use a huge amount of acid so the difference in cost/efficiency isn't all that much to me. If it saves me $50 over the course of a year to use the higher concentration, I don't know that it's worth it.
    They sure do sell full strength MA in California. I buy it 4 gallons at a time
    Swimming Pool Liquids - Muriatic Acid
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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