12 days and 4 gallon pots are not dry, what you think?

Discussion in 'Growing Marijuana Indoors' started by johnjohn, Sep 26, 2010.

  1. this happens almost every time i grown in 4-5 gallon pots. The first time I transplant from beer cups (1 week old plants) and heavily water the 4 gallon pots before, it takes forever for these things to dry up.

    After second watering its usually once every 7 days in veg and once every 3-4 days in flower, but when they are so young, and first time go into 4 gallon pots, it takes a really long time for them to dry up.

    I was going to water today but I think its good to let it dry so roots can develop better, but its 12 days, damn, should i be concerned about anything? Anyone have similar experience?

    temp: 70-85

    humidity: 45%-70%



    50% FFOF
    30% Roots organics
    10% perlite
    10% light warrior
  2. It's definitely true that in larger pots the soil will take longer to dry out. But there are many factors at play here:

    - What shape are these pots? Are they tall and narrow like large paint buckets or kitty litter bins? If so then they a low ratio of exposed soil surface area to total soil volume, so moisture will evaporate more slowly.

    - I assume you have proper drainage holes in the bottom of the pots? Could they use more drainage holes? The runoff water is allowed a place to go without sitting in a pan under the pots and soaking back to the soil?

    - Your soil mix could be too dense. Next time bump up the perlite and also add some clean sand for good measure. You basically cannot overdo it with perlite or sand (vermiculite also can help drainage but too much can affect pH).

    - Do you line the bottom of your pots with a layer of rocks before adding soil? Helps drainage.

    - You could try to aerate your soil by gently wiggling a probe or a chopstick or anything like that down into the soil in various places around the pot, letting air down into the soil.
  3. thanks toastybiz, really good recommendations there. I def need to use the rocks at the bottom, but obviously this cannot be applied now, i need to do this next time.

    They are tall and narrow, but they do have really nice and big drainage holes so the drainage holes are not a problem.

    As far as soil, i think its a pretty good mix. I know FFOF needs perlite so for 50% Ffof i got 10% perlite and 10% light warrior which is also soilless stuff. Roots organic should be good on its own.

    "aerate your soil by gently wiggling a probe or a chopstick or anything like that down into the soil in various places around the pot" - this is great, i will try this, but what if those sticks cut up the roots, should i worry?
  4. also toasty, do you think that long and narrow vs wide and short (both 4 gallons) causes differences in the way the plant looks and grows?
  5. That's why I was saying to gently wiggle it down into the soil. You probably will damage some root hairs, can't avoid that and not a huge deal, what you want to avoid is damaging a larger root branch, by wiggling it down your probe should slide around those.

    Within reason, no. But what a tall and narrow pot does do is give you a lot more root volume tight under the light, so you can get more out of those 5-gallon pots than some that are wider and shallower just because the wider pots will have more of the plant further from the light.
  6. thanks man, great info.
  7. anything i can do at this point to dry out the pots quicker? i have wiggled 8 sticks into the soil but still want them to dry faster. Not looking for perm solution just one time, can i put a heat rug under the pots or something?

  8. You answered your own question with your first statement.

    Those seedlings are vastly over potted.

    Try beer cup->1 gallon pot->4 gallon pot.

    You also IMO have too little perlite in that mix and is probably too heavy. 30-40% would give you better aireation and drainage and you don't need rocks in the bottom. After a few waterings the soil drifts down, fills up the spaces between the rocks and they end up doing nothing but adding weight.

  9. If I were you, I'd definitely up the perlite to double that at least, especially with FFOF. I love the stuff, but it just compacts to mud.:cool:

    Also remember that the water doesn't just evaporate; it gets consumed. So try to keep in mind that water/soil ratios are good for controlling soil conditions and all, but if there aren't roots to drink it, its not really going anywhere.

    Just my 2 cents.
  10. i dont think overpotted is correct, many people grow right away from 5 gallon pots and all is good. i know i should have added more perlite, made the soil mix better but at this point, currently, when the plants are already in the soil for a month... now,

    what can i do to make the soil dry out faster, temp solution:

    - turn up the heat
    - lower humidity in basement

    what else?
  11. Wait for the plant to consume it I guess and learn from the experience. :confused_2:

    If you get impatient and try something radical, you will more than likely end up hurting the plant. Just let it be.

  12. i dont want to overwater because i 5 days ago after watering i noticed that my run off ph was 5 and i had a cal/mag deficiency. 2 days later i watered with 7.8ph gallon which brought run off to 5.9 and then i hit them with 9ph gallon which brought run off to around 6.5.

    they are still suffering from some cal/mag lockout due to low ph so next watering i want to flush or go with ph to the point of getting 6.8 at run off, maybe even feed some cal/mag but i don't want to overwater so i want the pots to dry out first.

    now, any ideas?
  13. powdered dolomite lime for cal/mag and pH.

    Lowes has the powdered, no where else. It's labeled 'ground dolomite lime', usually close to the pelletized lime that you don't want.

    ~$5 for a 40# bag. Get some before you water again.

  14. Perhaps next time try the Fox Farm Happy Frog. I've found that its not quite as heavy as the Ocean Forest. The Roots Organics is also good stuff, but again, I found it to be heavy. I use more perlite than you do, and could water every day if I wanted to.

    So - try the FF Happy Frog, and step the perlite up to 30%. I would also, and hear me out - work on your rooting fertilizers. I use Canna Terra Rhizotonic, which is a rooting only food. Myccorhizae innoculants will also help. ( I usethem by making compost teas) The point I am trying to make here is to develop your root zone as quickly as possible. More roots will suck up the moisture quicker than less roots, and also your plants will grow 10 times faster with a large root ball quickly developed. There are some real good products out there specifically for your root zone. I use 4-5 gallon pots, and 2 weeks out of party cups I am filled with roots, right up to the surface. Your root zone is as important, if not more important, as whats above the soil line.

    But there, I've made my point about the roots - right now you need to dry out.

    I looked, but did not see any mention of a fan. If you can afford even a cheap one, get a fan moving across the top of your soil, that should help! I also liked the idea of aerating it gently with a thin rod - between the areation and a fan, you should be ok pretty quickly.

    Good luck!

  15. #15 johnjohn, Oct 4, 2010
    Last edited by a moderator: Oct 4, 2010
    always have a nice oscillating fan on the girls, and now got 8 long skewers in each pot... but the basement has like 60-80% humidity so they will not dry that fast.

    wet, i will try to get that powdered dolomite lime at lowes next time i water, thanks, is it this one:


    the faster i can water the faster the plants can get better, but i just watered 6 days ago and then 2 days after that also watered, i dont want to overwater, so trying to find ways to get pots to dry up faster....
  16. Ideally, you want to find the powdered, not pelletized, but that should work if you cant find it. I think the bag says ground instead of powedered. Try Lowe's maybe.:)
  17. I go from beer cups to 2 gallon then 5 or 7 gallon. when they go in the 2 gallon I give'em 1 beer cup of water. When they go into the 5 gallon I give'em 2 beer cups of water to start then after that just 1 beer cup of water every 4 days for like the first 2 weeks then go up to 2 cups by the day 20 of flowering there taking 3 to 4 cups every 4 days then up to 4-5 cups for the rest of flowering. Only give'em what they need they like that better you might have to water more often but it's better for them. I used to do a full soil soak when I would transplant but over the years I found it was not necessary and would cause more problems then good the plant root are there yet and all you get is high humidity, root rot ,mold etc.
  18. dude make sure ur pulling out these sticks after you use them to make holes. you shouldn't need 8, only one. and yah i bet your roots are either nit there or not dense at the bottom. what you need to do is pull the plant out and remoce most of the loose soil from the roots and repot into a short fat planter using ffof + 40% perlite and another tip. assuming u keep the crappy tall planter you might try drilling a ton of holes in the side all around the pot and get air flowing over the holes it will aid in drying. you can overdo this so start slow with the holes and make sure the planter still fundamentally functions to actually HOLD soil in it

  19. These are all good points but I have to disagree with the second to last point. It is a huge THEORY that putting rocks or pebbles in the bottom of your grow pots "helps" with water drainage. It actually does the complete opposite. Water does not like layers. Now I am not saying that soil mixtures is a bad thing, because it is not. However, layers in soil is a major no no. Being a horticulture major this theory has been tested and proved over and over again. Water travels best through smooth mixture. When the water travels its path through all of the soil and then all the sudden there is a bunch of rocks in its path, it is all of the sudden not used to its path of travel and drains slower then it would with just soil. Ask anyone educated in horticulture and they will ALL tell you that you never want to add layers to soil. Sorry I am not trying to be rude I am just taking horticulture in college and we have just been tested different soils and mix's and watching the water travel with clear plexiglass containers. Pebbles and hydroton at the bottom of the containers actually block up the water.
  20. "dude make sure ur pulling out these sticks after you use them to make holes. you shouldn't need 8, only one"

    -really? why pull the sticks out? and why not use 8, the more sticks the more aeration to roots right?

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