ppm of tap water - whats tolerable?

Discussion in 'Hydroponics' started by Dr. VanNostrin, Feb 21, 2008.

  1. Dr. VanNostrin

    Dr. VanNostrin Registered+

    is there a cutoff level for ppm of tap water where it shouldnt be used? i use distilled and am wondering if i even have to.
     
  2. gainesvillegreen

    gainesvillegreen Registered+

    It really depends on the contents of the water more than the actual TDS levels; however, I would say the 250-300PPM area for tops. I have used it higher (400PPM) with no problems though, so...
     
  3. herbie the love bud

    herbie the love bud Registered+

    Some people say 200. But I use RO water so I can't tell you for sure.
     
  4. xcrispi

    xcrispi Registered+

    General Hydro recomends hardwater micro after 200- or 220 ppm .
    I'd say anything over 220 ppm is good reason to use distilled / r/o .
    Peace
    Crispi :jointsmile:
     
  5. Dr. VanNostrin

    Dr. VanNostrin Registered+

    if my tap water is in the 400s, could i just dilute it with distilled instead of using just distilled and adding cal-mag? my goal is to not have to buy tons of distilled water and not to have to add cal-mag
     
  6. gainesvillegreen

    gainesvillegreen Registered+

    You absolutely can, that keeps a good level of the nutrients you're missing in distilled alone.
     
  7. herbie the love bud

    herbie the love bud Registered+

    Is there anyway you can put in an RO system? A good one should cost between $150 and $200. Either way you won't need a lot of CalMag. I use a half a teaspoon per gallon now (2.5 ml).
     
  8. Dr. VanNostrin

    Dr. VanNostrin Registered+

    how do ro systems work? i dont mean how do they purify the water, i mean how do they hook up to your water system? i thought i saw something about it taking time for the ro system to produce the water. is that right?
     
  9. Mississippi Steve

    Mississippi Steve Registered+

    I am still trying to figure out PPM of what?? Chlorine?? Bromine?? Sodium Chloride?? Fecal Solids?? what?? I don't understand "TDS levels".
     
  10. herbie the love bud

    herbie the love bud Registered+

    They generally use a saddle clamp to connect the 1/4" supply line, then they have a line to the drain and a line to a tank or rez.

    Pretty simple. Yes, they do produce water slowly, generally 25 gallons per day. The faster the production, the more expensive, although I saw a 90 gallon per day system for $200.

     
  11. herbie the love bud

    herbie the love bud Registered+

    Not sure if that was a question or just rhetorical. Yup, you're right. PPM of tap water doesn't mean shit. Doesn't have sticker on the water with "Guaranteed Analysis".
     
  12. Mississippi Steve

    Mississippi Steve Registered+

    Actually it was a question...having a little chemistry background, and playing around with my own grow, I would like to know what they are talking about.

    BTW there are test strips that are available for aquarium water that will give you levels of a dozen chemicals and minerals for just a couple of bucks.
     
  13. gainesvillegreen

    gainesvillegreen Registered+

    Wikipedia - T.D.S.

    TDS is Total Dissolved Solids, or the measurement of ions and some other substances dissolved in the water. This is a measurement of the ions/salts in a soution. In your setup, this is basically measuring the amount of fertilizer/material in your water that your plant can/will absorb.

    Quote from wiki: "The most common chemical constituents are calcium, phosphates, nitrates, sodium, potassium and chloride."

    See the most common constituents? Notice the nitrates for N supply, phosphates for P, and potassium for K? Calcium and magnesium are also fairly common in this application, especially in 'harder' waters.
     
    Last edited: Feb 25, 2008

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