Welcome to OrchidsForum.com. We are a friendly online community for Orchid Growers all over the world. If you haven't joined yet we invite you to register and join our community. Hope to see you on our forums!

Safe pH reducers?

Discussion in 'Orchid Culture' started by Chris, Jan 23, 2009.

  1. Chris

    Chris New Member

    Messages:
    1,479
    Likes Received:
    21
    Location:
    Austin, TX
    Do any of you use a pH reducer for tap water? I need to use some tap water for some plants, but the water that comes out of the faucet here has a pH of 9.0-9.5.
     
  2. Kyle

    Kyle Member

    Messages:
    135
    Likes Received:
    4
    Location:
    Geographic center of Canada
    I use vinager to reduce the pH of my flasking media with no harm to the little plants. I would assume it would work for water.

    Kyle
     
  3. Chris

    Chris New Member

    Messages:
    1,479
    Likes Received:
    21
    Location:
    Austin, TX
    Thanks Kyle!
     
  4. Clark

    Clark Gator Member

    Messages:
    1,297
    Likes Received:
    38
    Location:
    The Gator Nation
    Chris, what makes the pH so bad? Drinking water should not have a pH that high. Back in Tampa you got your drinking water from a limestone aquifer (basic to neutral) that most likely ran a pH of 7.5. The surficial aquifer here (the one above the limestone one) runs a pH like rain water, around 4.5 to 6. Does your drinking water come from an aquifer were the utility has to treat it to make it soft? Is you pH meter calibrated?
     
  5. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,521
    Likes Received:
    3,320
    Location:
    Santa Rosa, CA
    A lot of cities increase the pH of perfectly good water to reduce leaching of copper (so they say). I think it is the law. San Francisco used to have great water, now it is pH 9.2.

    Before I switched to RO, I used phosporic acid to reduce it from the 8.4 out of the tap. Hydroponic stores sell a product call "pH Up" and "ph Down". I have used the pH Up with my RO water when the fertilizer makes it too low. It works very well.
     
  6. Chris

    Chris New Member

    Messages:
    1,479
    Likes Received:
    21
    Location:
    Austin, TX
    Clark, the aquifer here is Cretaceous limestone, and runs 7.5-8. Treatment here to soften the water involves dumping huge amounts of CaOH, with the result being a very high pH.
     
  7. Clark

    Clark Gator Member

    Messages:
    1,297
    Likes Received:
    38
    Location:
    The Gator Nation
    Chris, the secondary drinking water standard in Florida is a pH of between 6.5 to 8.5. You need to complain about the water quality. Oh, wait you're in Bush country, there are no standards.
     
  8. nine.tigers

    nine.tigers Member

    Messages:
    70
    Likes Received:
    4
    Location:
    Tianjin, People's Republic of China
    I have been using Oxalic Acid to soften the tap water and lower its PH value as well. The processed water in that way has been used on my orchids for 4 years, and no harmful effects have been observed. I got Oxalic Acid (a.k.a "ethanedioic acid") from my neighborhood grocery. It is sold (US$ 2 per 500 grams) for cleaning ceramic tiles. You can also get it from Ebay. The processing steps are given below.

    Step 1: add 0.5 - 1 gram of Oxalic Acid to 10 liters of tap water (Ph 7 - 9.5);

    Step 2: Stir the water to make the Oxalic Acid melt evenly in the water; 10 minutes later, the water will look cloudy, because the Oxalic Acid, when lowering the PH value, will seperate and deposit the calcium and magnesium in the tap water.

    Step 3: Waite until the water becomes clear: the depositing process usually lasts for 2 - 3 days.

    Step 4: Draw the clear water into another utensil for use. The clear water is almost RO water with PH 5. A little more Oxalic Acid will make it PH 4 - 4.5. A little less Oxalic Acid will make it PH 6 - 6.5. Don't extract the white residue on the bottom.

    Note: For the first few times, you may confirm the PH value of the processed water via test paper. If the PH value is too low (let's say, below PH 4), exposing the water to sunshine for 2 days will raise its PH value to 5 - 6.
     
  9. Ray

    Ray Orchid Iconoclast Supporting Member

    Messages:
    1,735
    Likes Received:
    535
    Location:
    Oak Island NC
    Any acid will work, so you ought to be thinking of safety and cost. I have sold a lot of the pH Up and Down products, and they are designed for horticulture, after all.
     
  10. Alexis

    Alexis New Member

    Messages:
    2,893
    Likes Received:
    21
    Location:
    Redland, Miami FL, USA, Earth
    Lots of good advice. If you can't find pH Down, try pHlo. I find it at my local ag supply warehouse.
     
  11. Einstein

    Einstein Expatriate

    Messages:
    124
    Likes Received:
    0
    I had good success with phosphoric acid, General. It's relatively inexpensive and a little goes a long way. You probably wouldn't need more than 2 or 3 drops per gal.
    Most chemical suppliers have it on hand and you being a Mad Scientist should have easy access to it
     
  12. Chris

    Chris New Member

    Messages:
    1,479
    Likes Received:
    21
    Location:
    Austin, TX
    Thanks for all the advice folks. The most readily available thing I have is nitric acid, so I'm gonna see how that works.