Ph=ppm?

Discussion in 'First Time Marijuana Growers' started by Apu42, May 9, 2011.

  1. Am I understanding this correctly?
    So, simplified, more nutes=lower PH/PPM/more acidity while watering with distilled water with 0PPM=higher PH/PPM or less acidity?

    If Im wrong on this then I must not understand the relationship between PH/PPM.
     
  2. That description does fit certain circumstances but is an oversimplification. If you're using an acidic fertilizer, then more in an aqueous solution will lower the pH and make it more acidic up to the acidity of the unmixed fertilizer.

    You're talking about water having a "higher pH," which is true when compared to an acidic fertilizer but it would help you to think of water as having a "neutral pH." Alkaline substances have a higher pH than pure water and acidic ones have a lower pH.

    There are many alkaline fertilizer out there. 75% of the ones I use have a pH higher than water.
     
  3. Thanks. Reading this combined with that other guys thread about PH near the top has given me a slightly better grasp on this. Im going to buy a PH Meter (these strips I stole from work suck).

    So Im thinking it would be better to have a fertilizer that is slightly acidic vs one that is slightly alkaline? Or would a PH-neutral fert work best and just use ph up/down? I garden no other plants, just my little (hopefully!) girls :)
     
  4. Always keep a secondary means of pH testing that doesn't go bad on hand when using mechanical or electronic pH meters, as they're known to have or develop problems. I had a nice digital one read incorrectly straight out of the box. Broad spectrum pH drops are the best secondary (& good primary) pH testers imo, and can be bought for as little as about $7.

    The best pH for a fertilizer solution is the best pH for your substrate; about 6.5 for soil and around 6 for soilless. Anything too far from this will need to be adjusted so the closer to that number the ferts are, the less needs to be done to correct them. That said, I wouldn't let the pH of a great fertilizer stop me from getting it unless choosing between two similar ones. Some of the absolute best ferts have crazy pH's. I use a 0-0-30 organic fertilizer that is simply awesome for flowering but is pH 12.
     
  5. Id like to try em. Any idea where I could buy them? Home depot and Lowes keep dissappointing me by never having what Im looking for. Wal Mart? A place that sells swimming pools that i know of? The hydro shop down the road sells it Im sure though everything sold there is inflated as hell.
     
  6. Search Google for either "graden center" or "hydroponics" and your area code. Click on the map showing businesses and call the closer ones. If there are just no garden or hydro stores in your area, the only option for getting good materials is to order stuff online. Good broad spectrum pH drops will at least display a range from 4-8. The garden sections in dept stores like Walmart or Lowes don't carry any of the good stuff. Imho, the only substances there useful to an experienced grower are seed starter soil & lime.
     
  7. no ph does not equal ppm, that aren't at all the same

    ph as described measures how acidic or alkaline something is, but having a low or high ph doesn't = a low or high ppm - you use your ph to make sure your plant is able to get the right amount of nutrients and is not locked out

    ppm is a measurement of how much "stuff" is in the water, this can be things from tap water, like chorline, your ph up and ph down can add to your ppm, as will your nutes, you pretty much use this to determine how much nutes are still in your water

    i'd recommend a ppm meter over a ph meter if you're only gonna have one since you can use the drops to get a good idea of your ph but you'll have no idea what your ppms are at

    if you dont know your ppm then you dont know how much nutes to add or how fast its going through nutes, when your ph gets high your ppm meter will tell you if you need to add ph down or if you can add more nutes
     

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