can someone explain the flushing process????

Discussion in 'Growing Marijuana Indoors' started by boricuapuffer, Feb 17, 2009.

  1. ok so here's the deal i currently have a plant thats flowering and im reading up on the flushing process, but i am finding way too many conflicting explanations on it, and i was wondering what is it that i have to look for to initiate the flush and for how long to i keep doing it before i chop the plant down. thats it, a pretty simple question.
    i am doing hydro and using General hydroponics nutes. any and all advice is greatly appreciated, thank you my GC brethern for lending me a few minutes of you time

  2. As best as I understand it, you should flush the plant a couple of weeks before you chop it. By flushing, I believe you are supposed to water until you start seeing the excess come out of the holes of the bottom of the pot. At that point you should stop. What I don't understand myself is if you should continue to water everyday or if you need to wait until the first couple of inches of soil is dry again before watering again. Anyone?
  3. Flushing is when you run enough water through the soil so that excess nutrients and salt buildup are flushed. This ensures a clean soil from anything that could potentially harm your plants.
  4. flushing is when either u have salt build ups in soil = 3x the amount of pot size, eg: 3gal pot = 9gal flush. flushing when near harvest is when u give your plants plain ph'd water (w/ mollassas if wanted) for the last 2wks b4 harvest vs your nute feedings, & just water til u get about 1/3rd runoff

  5. this is what i mean, way too many conflicting advices,:( by the way guys i truly appreciate your input:eek: but my question was when do i initiate the process of flushing, is there some sign my plant shows me that says "papa flush me" or do i go by some sort of time table and i do believe all your advices were geared towards soil grows, i am hydro fellas, not sure how much that differs but i dont know how run off correlates to hydro:confused:, in either case thanks for at least responding!:D

  6. Well, just like everything else in growing, everyone has their own methods. Some growers flush every ten days of growing, some check the EC of the excess runoff after watering for high salt levels, some just keep an eye on the plants and watch closely for burn and "feel" it out. Generally flushing is something that refers to a soil grow, since you are pouring the water through the soil to wash out the excess salt buildup. I'm not a hydro expert but I've heard recommendations to change your water every two weeks to avoid mold and bacteria build up, which is probably the hydro equivalent to flushing, but not exactly the same since you can constantly monitor your solutions EC for high salt levels. This is something you can't do as easily in soil.
  7. thnks for your input! i have been doing research on flushing for 2 weeks now and can seem to come up with a solid source on hydro flushing, if there is such a thing, so i felt compelled to start a thread and see what other GC dudes have to offer in terms of advice and info
  8. #8 toastybiz, Feb 18, 2009
    Last edited by a moderator: Feb 18, 2009
    I see these explanations as variations but not "conflicting" advice. What everyone is telling you is this: think of flushing as a washing or rinsing of your soil. Basically all you do is run a lot of water through your soil so that it washes out impurities. Everyone is telling you that.

    Now, exactly how to do it and when and why, yes there are some variations in that, but it's not a precise process, you're basically just running a lot of water into your soil and out the bottom. Standard recco is at least 3x the soil volume, I wouldn't do less but nothing wrong with more. Just make sure the water you use is around room temp, and don't put it in so fast that it starts filling up the pot on top of the soil, give it time to soak through. Ideally you should flush with pH adjusted water, but that can be a lot of water to adjust the pH so I have found that you can cheat a little by having just the last gallon or so pH adjusted, it will push out most of the water that went in before it anyway.

    Flushing should be done at the following points during your grow:

    - When you switch to 12/12 lighting. You also will be changing your nutes at this time (from veg to flowering nutes), and flushing will remove any build-up in the soil of the old nutes and get it nice and clean for the new nutes.

    - A week or two before harvest. If the bud has lots of nutes in it when you harvest it will taste terrible, so you stop feeding a week or two beforehand so that the plant taps into its stored nute reserves so there are less left in the plant at harvest. Since you don't want to feed the plant anymore after this point, you also flush to remove any nute build-up in the soil. Some say do this 1 week ahead, some say 2, it's all good. Once you flush at this point and stop feeding you don't need to keep flushing, you've already cleaned out the soil and you haven't added any more nutes so no need to flush again.

    - Any time during your grow that you feel a flush could be beneficial. If you are seeing signs of nute burn, for example, that means you are giving too much nutes so the soil is over-saturated and needs to be rinsed out to remove the nute build-up.
    Besides washing nutes out of the soil at specific times, during the grow the plant's process of uptaking nutes creates salts and other waste byproducts that are left in the soil, and flushing rids these.

    Flushing is basically simple but can be a logistical pain in the keester. You need to do it where you can handle all that runoff, so usuallly not in the grow space unless you have a drain. I hoist my plants up to my shower.

    I know of what I speak, and so do many if not all of these other guys. Sometimes there is more than one way to skin a cat, so if you find some variations in the advice you get you should appreciate all of it, take it into account as you are comfortable with and then make a decision on your own.

    Edit: OK, I missed the part about you being a hydro grower. Yes there is flushing for hydro but it's not the same as for soil. Suggest you put that into the thread title next time. If you don't get good hydro help here try the Advanced section, a lot of hydro talk there and possibly stickies and such on topic for you.
  9. thank you kindly for this informative piece of info good can i apply this to my hydro grow???:confused:
  10. Can you edit the title of the thread to include the word hydro? If you don't get good hydro help here in the Indoor section try the Advanced section of GC, a lot of hydro talk there.
  11. For your hydro grow, just feed your plants straight pH-adjusted water as opposed to your nutrient solution for the last week. Drain your res, rinse it out, and fill it with clean fresh pH-adjusted water. Some people recommend changing this fresh water every couple of days as it absorbs salts or something. I forget.

    If you want you add Clearex (or molasses)..

  12. thnx man i got the same info from 3 other hydro growers, will do !

Share This Page