Hardness in water???

Discussion in 'First Time Marijuana Growers' started by bakin420, May 7, 2011.

  1. Hey GC, i just read up on my water and my hardness is about 164 MG/L...
    I don't really know what it has to be at but is it too high??
  2. Do you have a reverse osmosis filter in your home?
  3. no i do not..
  4. They do have nutrients designed to be used with hard water like in your situation
    You would just have to be sure that the nutes are for that purpose as any other types would probably not be as available to the plant otherwise
  5. What does the hardness in water do exactly??
    I haven't really done anything about it and have been using it
    along with my foxfarm nutrients and everythings been cool
  6. Hard water has can have alot of calcium and magnesium in it and it can have a high EC or PPM reading. If doing hydro EC or PPM is really important to keep in check as it will help determine how much nutrient uptake the plant is getting.
  7. Okay i see, so do you guys recommend a Reverse osmosis with my hardness??

  8. If you can get that in heck yea why not
    I mean even you can drink the water if you wanted to (some bottled water quality)
    I buy my own water so it has been tested by myself 5.0 ph and 0 everything else

    R/O is the way to go if you don't have time to worry about testing the water,letting it sit out for a day or 2, and I guess if you have hard water it can take the pain out of the cal/mag situation and give you some softer water to work with
    Win/Win imo
  9. Does anyone know what the EC readng in mS/cm would be for this water, at 164mg/l?
  10. I have really hard water where I am. I run my water through two Britta filters. They don't catch everything, but they're better than nothing and much cheaper than R/O systems.


  11. #12 Wardrobe, May 8, 2011
    Last edited by a moderator: May 8, 2011

    Thanks JayF, for waking me up. Actually, I already knew the three conversion rates, but didn't think forward enough to convert mg/l to ppm. (1 million mg per litre.)
    Of course 164mg per litre is 0.33EC by the Hanna scale. I'm a bit slow sometimes. In my defense, I only work wth EC values.

    This is another standard that should be standard.

    Instead, Aussies use 0.7, Americans use 0.5 and Europeans use 0.64. A pain in the arse, especially when the ppm value is quoted without the conversion factor.

    In all the (my) confusion, I forgot to add that 0.33 isn't that high. As I understand it, from the Canna website, 0.2 is considered soft, 0.4 is normal and 0.6 is hard water. I'm sure this'll open up a can of worms, but that's my 2c worth.
  12. No worries.

    The reason they can't be standardised is because Electrical Conductivity and ppm are not necessarily the same for any given solution. A conversion table like the one above just gives an estimation of one from the other based on dissolved solids found in your average tap water and nutrient solution. In reality, the EC of the solution depends on what's dissolved in it.
  13. That sounds logical but doesn't account for the fact that different regions use different conversion factors, because that's not reliant on the exact composition of the dissolved solids.

    And yeah, the EC is only the conductivity, not the content.
    I've seen two different definitions of TDS - total dissolved solids and total dissolved salts. The second is more accurate, because solids in general aren't necessarily conductive.
    Following that to it's logical conclusion, TDS should be total dissolved salts AND metals.

    Still, I wish they'd settled on one conversion factor, for simple folk like me that like everything to be easy.

  14. My waters PPM on a Bluelab combo meter is around 200 and if run through a Brita water filter it drops it down to about 100, dont recall if that was a single pass through the water pitcher filter. As for an RO system I would reccomend one with a small holding tank. Another person here got one without a holding tank and it runs constantly and really put a big increase on his water meter usage. I let my water sit out for 24 hours before using. Thats where 3 gallon refillable water bottles from Wal Mart comes in handy.
  15. #16 Wardrobe, May 8, 2011
    Last edited by a moderator: May 8, 2011

    0.5, 0.7 or 0.64? Only out of interest - either way it dropped by 50%.

    I was on the way to bed, but there's a great doco on TV on indoor growing, so I'm up for a bit longer. Recording it.
  16. Is it different regions or different equipment manufacturers? I've never really looked into it, so I'm not sure.

    It's a long time since I took a chemistry class. But if I remember rightly, salts have a very specific meaning in chemistry. They are made up of positive and negative ions and for some reason because of this they can conduct electricity when in solution.

    The metallic elements present in the water and fertilisers are in both elemental and compound forms, salts and non-salts (conductive and non-conductive). This is probably why they use the total dissolved solids. Because all the compounds are relevant. As I said, I've never really looked into it. This is the first time I've really thought about it, so I might be completely wrong.

    Thanks for the info. I've been without an EC meter so far this grow. I'm on a budget and haven't found a cheap one yet. I've been buying bottled water at 47mg/L TDS, but figured running tap water (which we don't drink) through two filters will bring it down enough. Sounds like it should.

  17. Probably a bit of both. Technically, it's different regions, but it's a bit of a grey area since we buy meters from all around the world.

    ^Have a quick look on eBay. You can get EC meters for almost nothing. I bought an EC meter / pH meter set for under $40. The pH meter was shit, (I have a Hanna meter on the way), but the EC meter is fine.

    Sounds like you know a bit more about chemistry than me.
  18. I was testing it on PPM setting. So on a Bluelab Combo meter it would have an EC of 0.3.
  19. Sorry, I didn't make myself very clear. I meant which conversion ratio, 0.5(500), 0.64(640) or 0.7(700).

    ie. 200ppm is 0.4EC Hanna, 0.32EC Eutech or 0.29EC Truncheon.

    That's what I meant earlier. Without the conversion factor, ppm is a grey area. EC remains the same regardless.

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