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Ph up and down vinegar and baking soda?

Discussion in 'Hydroponics / Aeroponics' started by pow monster, Dec 28, 2007.

    pow monster

    pow monster Active Member

    I have made homamde ph testing papers but I need something to actually adjust the PH. This is for a DWC Hydroponics setup. I have heard you can use baking soda and vinegar to adjust PH. Is this true our is their other household
    items that can be used to adjust PH?

    papajock Well-Known Member

    also can use concentrated lemon juice for ph down. I use apple cider vinegar for down and works fine for me in a dwc. never needed any up.
    pow monster

    pow monster Active Member

    concentrated lemon juice for ph down sound like a great idea. I have some around the house and the addition sounds natural. If I can drink it when I add it to some iced tea my plants can drink it also.

    email468 Well-Known Member


    moon47usaco Well-Known Member

    Actually citrus is very good for keeping control over bacteria... With long hiking/camping trips with bottled tap water it is recommended to put lime or lemon juice in the water so that the contained water does not grow unwanted bacteria...

    Unfortunately this will most likely kill good bacteria as well... See my post on Tea... Some micro organisms are good for your plants...

    How that citrus will interact with your nutrients is another story but my guess is that it will be safer with organic nuts rather then non organic... I am no chemist though... =]

    EDIT.. i just read that post about slime... I wonder what elements the ph adjuster reacted to... I am going to go with the aeration of the water and air-stones... I will have to look into that later... =]

    email468 Well-Known Member

    You are correct that citrus juice will deter growth of some bacteria but keep in mind that you'll be trading bacteria that doesn't like acidic environments for acidic-friendly bacteria.

    Zhu Well-Known Member

    I use discus fish ph balancer, balances ph between 5.8 - 6.8 its so easy a tsp a week and your good.
    Masterbear likes this.

    Earl Well-Known Member

    My guess is you smoked some killer dro and now you want more,
    or you think you can make a fast buck.

    Well, there is a reason why the stuff sells for the price it does.
    Growing Da Dro is expensive Bro.

    Meters. nutes. lights. all cost $$$$

    Here are a couple of things to think about.

    You can grow hydro without paying attention to the rules,
    but your yield will greatly suffer,
    and you will have better results if you throw some seeds in a pot of dirt.

    So don't buy those expensive hydro nutes
    unless you are going to go all the way.(at least get a meter)

    One of the most imprtant things for a hydro grower to do,
    is to maitain the pH of the solution within the proper range.

    Your pH should not be moving up and down.
    It should move up.
    You should adjust it down.

    You are using tap water.
    (I am sure you are, since you won't spend money on the correct additives)

    Because of the tapwater,
    you already have too much Calcium in your nutrient solution,
    and when you use baking soda,
    you are just increasing the Ca content of your nutrient solution
    to a level that is unhealthy for your plants.

    This is a problem.

    Ca and Mg(magnesium) are molecules that will bond.

    If you have too much Ca it will "lock out" the Mg,
    and your plant will become Mg deficient.

    Mg is essential for THC production.

    You must stay away from baking soda (Calcium Carbonate).

    Only use a Potassium molecules for adjusting the pH up.

    Since you are using tapwater,
    you need to understand and follow the pH rule

    Following the pH rule is going to be very difficult to apply
    without a pH meter,
    and since you don't have a meter........

    I am hoping you can use this rule,
    to understand what is happening in your nutrient solution.

    Calcium is very alkaline and therefore it will absorb a lot of acid.
    Tap water is full of Calcium.

    and other chemicals that are alkaline,
    can absorb acids.

    This is called buffering.

    Better buffers for growing are:
    •Potassium Carbonate
    •Potassium Hydroxide
    •Potassium Sillicate
    (These will not bond with Mg.)

    Here are the rules for tapwater,
    or water over 50ppm and/or initial pH of near 8.

    After you add nutes to your water*,
    the pH should be close to 5.6.
    *(I am assuming you are at least using hydro nutes,
    and not some miracle grow type "dirt formula")

    If your water is very hard, over 50ppm Ca,
    then you will need to use an acid,
    like Phosphoric acid,
    or Nitric acid,
    to achieve the desired pH of 5.6.
    (impossible to gauge without a digital pH meter, $30 ebay)

    There is no way to guess how much acid
    you need to hit the target pH of 5.6.

    It could be as much as 5ml/gl, or as little as .5ml/gl(5 drops per gl.)

    You should always use an eye dropper to deliver adjustments
    so that you don't over shoot.

    An Eye dropper from the dollar store
    that is graduated in milliliters is perfect.

    Start with a small amount
    and measure the pH, then add more.


    Not adding any adjustment, will be better than too much.

    If you get it right,
    in a few hours,
    as the buffers(Ca) absorbs the acids, the pH will move up,
    and hopefully you will catch it before it gets too high,
    and re-adjust it back to near 5.6.

    You will need to continue to add very small amounts of pH down,
    at least twice a day, to re-establish the pH back at 5.6

    After doing this for a couple of days,
    depending on how well you keep the pH adjusted,
    the pH will become stable for a few hours,
    maybe even for a day or so,
    and then the pH will fall below 5.6 without adding any pH down.

    When the pH falls without you adding pH down,
    you have met the pH rule,
    and this is when it is time to change out the nutes,
    even if you have not met the "Add Back Rule"

    For almost all hydro nutes,
    it is best if you always let the pH move from low to high.

    Ideally you will maintain the pH at 5.6,
    but in reality it will probably drift between 5.2 and 6.2

    The time that this sequence takes will vary,
    1with the plant size,
    2the amount of water the plant is consuming/transpiring,
    3the concentrtation( nute load) of the nute solution (ppm).

    If you are growing with tapwater,
    the pH rule is the best method to determine
    when it is time to change the nutes.

    Change outs can be as long as 10 days,
    and as often as 4 days.

    If you must use tapwater,
    It is highly recommended to use a "Hard Water" nutrient.

    Using a 50% nute load,
    will give increased yield,
    if you are using tap water.

    Your rez volume per plant,
    the phase of your grow,
    and the brand of nutes you have,
    will determine how often you need to adjust the pH.

    Your job is to maintain the pH,
    and change out the nutes at the appropriate time.

    If you are really determined to have a cheap grow,
    you can save a little money by using Nitric Acid for Ph down.

    Nitric is just plain old battery acid,
    you can buy very cheap or get free, from your local auto parts store.

    Be very careful using this!
    It can permantly damage your skin, or eyes!

    N acid should be diluted in distilled water.
    N acid is still dangerous if not handled by laboratory standards.

    If you would like to understand more about growing hydro,
    please read this.
    CC Hydro 101 by Earl - Cannabis Culture Forums

    bassman999 likes this.

    Zhu Well-Known Member

    earl that post should be a sticky. very informative.

    GreekSoldier420 Active Member

    all i know of is another post where a poster put a mix of distilled water and baking soda to kill powdery mildew and has drastically hurt his plants. I advised to flush and use an organic solution of 9 parts water 1 part skim milk.

    GreekSoldier420 Active Member

    baking soda is sketchy

    blowinbig Well-Known Member

    that is awesome...this is something that everybody should read if it is their first grow in hydro

    prude Active Member

    Calcium Carbonate is chalk or limestone. It has a pH close to seven (neutral). Sodium Carbonate is washing soda and has a pH greater than seven (alkaline). Sodium Bicarbonate is baking soda and has a pH greater than seven. pH can be measured with about the same accuracy using a dye based indicator - a liquid or a paper which has been soaked in the liquid - pH test papers - much more economical. Class dismissed :)

    sicknasty Well-Known Member

    in general if it comes from something alive it can be used by something alive to grow. "Organic" is just a stupid word that makes people spend money on something they could get cheaper.

    Take it from a graduating this spring microbiology major. Those white guys growing are just facultative aerobes, single celled organisms can do a whole lot more than most people think. In fact I am working on a project to reduce soluble uranuim insitu underground using only dissolved dihydrogn as a proton source for bacterial metabolism. Its pretty crazy stuff and exciting.

    The white good stuff that covers roots is beneficial microbiological flora.

    (I know they are misspelled I just don't want google to pick it up)

    iamomeed Active Member

    I think you should get true pH adjuster not DIY and a real pH reader. ph paper isnt too accurate. Proper pH for hydro is very important. The other items wont break your bank account go to a flea market or pawn shop for better deals.
    Earl likes this.

    Earl Well-Known Member

    The pH of a sample of water is a measure of the concentration of hydrogen ions.
    The term pH was derived from the manner in which the hydrogen ion concentration is calculated
    - it is the negative logarithm of the hydrogen ion (H+) concentration.

    What this means to those of us who are not mathematicians,
    is that at higher pH,
    there are fewer free hydrogen ions,
    and that a change of one pH unit
    reflects a tenfold change in the concentrations of the hydrogen ion.

    For example,
    there are 10 times as many hydrogen ions available at a pH of 7 than at a pH of 8.

    This means a pH value below 7
    is ten times more acidic than the next higher value.

    For example,
    a pH of 4 is ten times more acidic than a pH of 5
    and a hundred times (10 X 10) more acidic than a pH of 6.

    This is why it is very important to maintain the pH
    as near to 5.6 as possible.

    The availability of micronutrients is pH dependant.

    Digital pH meters are the only way to come close.

    Strips are about as useful as a hand grenade,
    when close doesn't matter.


    Availability of nutrients.

    infamouse21 Well-Known Member

    seems 2 me that people need 2 jsut buy some real PH down.
    the good consintrated stuff only cost like 9-14$ for a bottle that will last around 2-5 months depending on res volume.

    ranunky Active Member

    That's some good advide there but battery acid is Sulfuric acid not Nitric acid. Don't use battery acid as Ph down.

    rawgit Active Member

    Hey Ed. Nice tap agua faq! Do ya have a RO faq?


    Shonuff504 Well-Known Member

    I got a question for you Earl or whoever is listening... I gave my plants some baking soda trying to raise the ph of the water and i also used tap water. Based on what you said above i'm guessing the baking soda raised the Calcium level in my medium, causing my plant to be MG Def. I gave them Epsom salt today thinking that it was just Mg def. My question for you is was this the right thing to do. Or should i just have flushed them. Well let me know. I'm about to go smoke a blunt and wait for an answer :bigjoint:

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