Aerating water cause ph to raise??

Discussion in 'Growing Marijuana Indoors' started by masterlights, May 14, 2010.

  1. Every time i mix up a gallon of tap water with a teaspoon of grow big i test it at 6.7 or so.that i put a air stone in and the next day i test it and its at 7.3 or 7.4..

    what could cause this??this time i left the gallon in a closed closet so light couldnt hit it and grow algae which could raise the stumped
  2. The airstone won't make the difference. It can be two things, either the grow big's ph doesn't stabilize right away, or your plant is up taking the nutrients and is healthy and hungry. Rising ph can be a sign of good nutrient uptake.
  3. #3 starcecil, May 14, 2010
    Last edited by a moderator: May 14, 2010

    If anything it's one of two of these:

    Are you using a ph adjuster? Chances are the buffer is wearing off over time. If you aren't using a ph adjuster then it's probably the lime or calcium that is more than likely found in your tap water.

    Those minerals are a very good buffer for water and will level their ph out to something stable no matter what it's changed too. Of course the higher quality the ph buffer you use the slower this will take place.

    The water where I live does the same exact thing even with out being bubbled AND run through a brita filter. Not much you can do about it. I just bubble it in advance, then add nutes, adjust and use immediately.
  4. yea its not a issue of the plants using the nutes bc its not talking about the water sitting in a gallon jug.after i add some grow big my ph comes to 6.7 so i dont really use ph adjuster.

    i think i ll just have to refill the jug daily so im not using water with a ph of 7.3
    im guessing the nutes change it or like you said the calcium deposits do.
  5. you use an airstone to evaporate out chemicals in your water right? you live in a city? Your water is probably fairly toxic. Buy reverse osmosis water. when i add nutrients I have to use 2 ml of ph up for a 2 liter with reverse osmosis. Trust me this is WAY better than using all the heavy metals, fluoride, chlorine and other chemicals to keep your water in range.

    The fact that you have to use an airstone means your water is to toxic out of tap to use on plants. It's not much better after the airstone.

    If you can only use tap, make sure you add your nutrients after aerating.
  6. i dont live in the city and my water isnt toxic.i use the airstone to airate the water not to help it out cuz its locatedin suburbs outside of a major city but my water isnt bad.water company's dont let the water be toxic..i dont even think my water company uses chlorine..they use something safer cant remember what it is though.

    i have a ro machine but right now im trying to save where i can on the bills.i figure tap is good for my seedlings bc its got some basic micronutrients.the ph of my tap is 7-7.2

    i was adding my nutes then the water i wouldnt use right away i would airate it over nite.then i was getting the higher ph numbers the next day.i think im just gonna use what i can then trash the rest of the water then start over the next day.
  7. Why don't you want to adjust it the next day when it goes out of range?
    And yes water company's deliver water in the 500 PPM range, I've seen it,
    thats almost in the un-acceptable range, toxic- don't know, I was told by
    the person who checked it should be no lower than 700 PPM, and that was few miles
    from downtown Los Angeles.
    Just curious where your saving not using your R/O filter vs. running
    an (assuming) electric air pump to aerate it, I use all my R/O waste in my yard & washer
    no waste.
    Often my water PH does change a little day to day, usually after I have added nutes, sometime temp can change it a few points.
    Happy growing,

  8. This man is right. Where I live a lot of things in the water are outside of acceptable limits, yet I don't know how they are able to provide it. Last years water report was listed as 700-800 ppm yuck
  9. I know this is an old topic but I just had to respond in case new readers come looking for answers to the same issue.
    Water fresh from the tap is high in carbonic acid (carbon dioxide), low in oxygen, and CO2 lowers pH.  When you let the water sit out, or aerate with an airstone, the CO2 is exchanged for O2, which equalizes the pH.
    People who have aquariums have long gotten used to aerating their water and then adjusting pH before doing water changes because fish are very sensitive to pH swings.
    If you need to adjust the pH of your water to optimize nutrient uptake in your grow, make sure to do so AFTER the CO2 has exchanged out.
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