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Should I stop using distilled water?

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    Should I stop using distilled water?

    Hi there,
    I have an Aerogarden Farm hydro system.
    First time I tried using distilled water (I'm into week 5).
    The water here is pretty alkaline, pH of 7.5 or so... so I thought that switching to distilled water would help keep the pH levels lower.
    But the changes in pH levels now are so rapid I can't keep up... every day with distilled water I use pH down and the next day it's back up to 7.5.
    Is it better to just go back to tap water? I'm confused as to the benefit.. it's been more of a headache than anything else.

    I used ro water for the last 2 years. I was having the same issue with ph fluctuations. Like adjusting twice a day. Because the store I got my water from stopped selling water during covid, I started using my tap water. I'll never use ro water again. My ph is super stable after my initial adjustments. I was worried at first but I'm having a great grow with my tap water. My ph is also 7.5 from the tap with a ppm of about 300


      RO and distilled water can fluctuate a lot in hydro. I found my tap a little too hard and tried RO as well and also found that it fluctuates more rapidly in hydro. What i ended up doing was doing approx 3/4 a gal of tap that i let sit out a few days and adding 1/4 gal of RO water and my water was stable and not so difficult to ph. That ratio may be different for you but what i did was try half and half at first then found it still fluctuated somewhat quickly. I raised the tap to 2/3 and found an improvement before i found the 3/4 as being the sweet spot. For me the benefit is i use substantially less pH up or down than i used to. Is it necessary? Depends on your water supply. Does it have a lot of chloromine or other problematic things in it? I could get away with not using it but i have had issues in the past when they change something in the water supply that caused weird issues and found that this has mitigated some of that.


        This is what Ed Rosenthal says about distilled water - " The pH of pure distilled water is very unstable and has no buffering ability. The addition of a tiny amount of an acid makes it very acidic and a small amount of a base makes it very alkaline."
        ​​​​​​3 X 3 gorilla. Promix soil . Green Planet Nutes
        Optic 4 - 415w COB 18/6
        Vortex in-line 6" fan


        • Tersky
          Tersky commented
          Editing a comment
          Lol that was my comment in TL;DR format! Well said!

        • Canuck147
          Canuck147 commented
          Editing a comment
          Just quoting Ed

        I'm so blessed to have tap water that is just hard enough! It's sourced from the Missouri river so it has lotsa calcium carbonate and trace minerals already in it. I've been using that with Aurora Soul nutes and never had a deficiency to chase down.
        Second state-sanctioned grow. Six plants in flower, three different strains.
        One Bruce Banner, two Granddaddy Purple & three Black Widows all from ILGM
        4'X4' flower tent, AC Infinity 4" fan and filter, Advanced Platinum P300 LED
        RDWC six grow buckets and a reservoir.

        Three Seedsman Blueberries & One Sweet Zombie from Expert in veg.
        3'X3' tent RDWC four grow buckets and a reservoir.

        Aurora Soul nutrients - Grow, Bloom, Infinity, Big Swell.

        On deck: Acapulco Gold & Laughing Buddha from Barney's Farm, Purple Haze from ILGM.


          Hhmmm glad I decided to let the soil and the plant decide for themselves where they want the ph levels. Now I just water, watch them grow, and try to understand what’s really going on. My tap water is also around 250-300 Ppm and the gh drops used to show it at blue? According to the colors that’s a ph of like 8. Something.. oh how I don’t miss those days lol.


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