Simple watering queston

Discussion in 'First Time Marijuana Growers' started by Suppa_K, Jan 22, 2010.

  1. I have 5 plants, in 3 gallon pots, mixed each with almost half perlite so I know water goes through it quicker but how much should I be watering my plants,now 22 days old, about 5-6". I have been giving them now I guess 2 liters divided between the 5.
     
  2. Water until you get about 30% runoff.
     
  3. Not to jack the thread or anything, but im doing research on how to grow, i just bought a book for it waiting on it to be shipped. But from reading the threads im still confused on watering also. how do you measure how much you need. You say 30% runoff, but 30% of what? 30% of a one liter bottle?
     
  4. You can't water too much but you can water too often. You can put 10 gallons through your pot each watering if you want - as long as the excess drains out. All that remains will be what the soil can hold and that's all you want. Overwatering means watering too often not too much. As to the runoff question, 30% runoff means 30% of the size of the pot you're using.
     
  5. ok so the OP is using 3 gallon pots, so you would want 30% of 3 gallons of run off?
     
  6. Whatever water goes in you want about 30% of that amount to come out the bottom. if you put in 1 liter you want 1/3 liter to come out the bottom. MJ likes to be saturated then allowed to dry out before watering again. the 30% runoff (out the bottom of the pot) allows you enough water to check the pH.
     
  7. 30% runoff? that seems like a lot to me. I agree that it's good to saturate the soil but that just seems like a bit much. But hey, what do I know.
     
  8. #8 toastybiz, Jan 23, 2010
    Last edited by a moderator: Jan 23, 2010
    I've heard the 30% rule of thumb but have never (knowingly) adhered to it. The point is to ensure you get good runoff, and 30% certainly is a good amount. BTW, I've always heard it as 30% of the water you put in, not necessarily 30% of the size of your pot.

    So, if you gave a total of 1 gallon you would expect a bit over a quart in runoff -- if you don't have that much then you water some more, realizing that the amount of runoff you are looking for changes with the amount of water you keep adding (In the above example, if after watering a gallon you see that you still need to water more and then put in another half gallon, for a total of 1.5 gallons, then you would want to see about one and three-quarters quarts of runoff). This all according to the 30% rule. Personally I think you are OK with less than 30%, as long as you get true runoff and not just a tiny trickle.

    Also, when the soil dries out sometimes it can pull away from the sides of the pot, be careful when you water that you don't get much down that side or it will just go straight to the bottom and run out, making you think you have "runoff" but you don't -- not the kind you want, anyway. Each watering you want to saturate the soil thoroughly, then not water at all until the soil dries out a bit.

    To the OP, 2 liters water for 5 plants in 3 gal pots sounds very light to me, are you watering until you get runoff? Are you pouring your water in slowly, in several batches a few minutes apart, as opposed to dumping it all in at once?
     
  9. So here's my question, you don't dump the runoff do you? You leave it?
     
  10. Ditto on what toasty says. I don't really follow the 30% runoff either. I water sufficiently (and slowly) so that my overflow saucers fill almost up. Toasty make a really good point on watering close to the edge and how the water takes almost a straight path out the pot once the soil has pulled a way a little. And no, you shouldn't let your pots sit in the runoff - empty it or suck it out with a wet vac.
     
  11. ^Yes, and ditto what John said about watering too much vs. watering too frequently. Overwatering results from keeping the soil constantly moist, which suffocates the roots. Once the soil is saturated during a watering, any additional water will drain out the bottom, that's why you can't over-water in a single watering. The key is to let it dry out a bit between waterings.

    And definitely dump the runoff, you don't want your plant's roots sitting in water, and depending on how you are catching your runoff if you leave it sit it can turn really rotten.
     
  12. I do water until I see a good run off and not just some trickle, but I will keep in the mind the edge of the pot thing, I know the dirt kind of degrades over a while but I will add more when its more dry. And I always let it dry, and yeah 1 liter did sound light so now I think I am going to give each plant its own liter because I get good run off with that.
     

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