macro/micro nute management

Discussion in 'Growing Marijuana Indoors' started by Red's Dreads, May 11, 2006.

  1. hey everyone, i've always loved this document i found through the grapevine... so i wanna post it for ya'all. ive seen it around before, so if this is another double post, my bad. but if not... my vote is to sticky it. enjoy

    Macro/Micro Nute Management

    Cannabis needs the correct combination of macro and micronutrients to live, grow and bloom properly. When plants are under or overfed, they will show symptoms of being unhealthy. Cannabis nutrients fall into 2 categories: macronutrients and micronutrients. Macro-nutrients are the elements that cannabis needs in large amounts. They are: nitrogen, phosphorus, potassium, calcium, magnesium and sulfur. Micronutrients are the elements that cannabis needs in small amounts (sometimes called trace elements). They are iron, manganese, copper, zinc, molybdenum, cobalt, boron and chlorine. Of all the micronutrient deficiencies in cannabis we will first see iron, manganese and zinc, most common in flowering and in vegetative growth. Though these elements are only needed in small amounts, they are very critical to the uptake of macronutrients.

    For instance, research in cannabis nutrient uptake has found that the right combination of iron and sulfur uptake is very important for optimal nitrogen uptake. This is just one area of micronutrients to macronutrient research uptake.

    There are many more combination of micronutrients to macronutrients that are critical to each other. This is why it is important to diagnose deficiencies or toxicities as early as possible. If one micro or macronutrient is not in its proper proportion, it can have a negative cascading effect on the rest of the plant's nutrient uptake.

    When you see something is wrong on your plant, where on the plant is also very crucial to narrowing down what the deficiency is. Macro and micronutrients fall into two other categories, mobile and immobile. Mobile nutrient deficiencies will show up in older growth first. Immobile nutrient deficiencies will show up in new growth first. Mobile cannabis elements are nitrogen, phosphorus, potassium, molybdenum, magnesium and zinc. Immobile cannabis elements are iron, copper, manganese, chlorine, cobalt, boron, calcium, and sulfur, however, sulfur deficiency is kind of tricky to identify, but most of the time will show up on older growth first. Sulfur is a semi-mobile element.

    Once you figure out your plant's specific deficiencies, you should ask yourself why this occurred.

    If you do have a deficiency and you are using a good quality hydroponic solution, most likely your problems are with your pH being too low or too high. Cannabis will grow in a pH range of <st1:time minute="55" hour="18">5 to 7</st1:time>, however this is far from ideal at the low and high end of that particular pH range. Your pH for sphagnum moss mixes and soils should be pH 6.2 - 6.5, with 6.3 being ideal. For hydroponic growing mediums, a pH 5.5 - 5.8, with 5.6 being ideal. Also, your nutrient strength (ppm or EC) may be too low or too high. If you are just starting out or an intermediate grower, a range of 1,000-1,400 ppm is ideal. If you are a master grower, you can drive your plants hard with CO2 and proper environmental conditions, and a nutrient solution of 1,800 ppm or more. You absolutely must know your cannabis strain and keep a very careful eye on your plants. Also, you should drain and change your nutrient reservoir every week. Do not wait 2-3 weeks to change your nutrient solution, because as your plants use up some elements, they are not using others. Eventually there will be an abundance or deficiency of one or more elements, causing nutrient lock-up or starting the domino effect of multiple plant toxicities or deficiencies. By avoiding some of these common mistakes and identifying nutrient deficiencies early on, you will be well on your way to a bountiful and healthy crop.
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    HIGH All, this is from MynameStitch who has done a lot of research on sick plants.

    Calcium (Ca) -Macro Nutrient and an Immobile element.

    Calcium is another important element that helps the plants cell walls, cell division in making the plants stems, stalks, branches stronger, as well as contributing to root growth, mostly the newer root hairs, Calcium also helps enhancing the uptake of K in the the plants roots. Calcium moves really slow within the plant and tends to concentrate in roots and older growth.

    When plants exhibit a Calcium deficiency the younger leaves are the first to show it as well as older leaves. The Leaf tips will die back, the tips may curl, and growth of the plant is stunted. The plant can show a weakness in the stems and branches, as well as a under developed root system that can lead to bacteria problems with roots dieing off. Having slow plant transpiration rates can aggravate the uptake of calcium. Make sure your soil isn't very acidic, for calcium gets harder to be absorbed through acidic soils, Which leads to having a plant that is deficient in Calcium. The leaf tips, edges and new growth will or may turn a yellow/brown color that happen in spots and often surrounded by a sharp brown outlined edge and then the leaf tips die back. If too much calcium is given at an early stage of growth it can stunt the growth of your plants. Having to much of calcium will also flocculate when a concentrated form is combined with potassium. The parts affected by a calcium deficiency are the roots. Stem or petiole, young or old leaves.

    Too much Calcium will lead to other micronutrient deficiencies. Calcium fixation is caused by many types of mediums such as: clay soils, unbuffered coco and humus. The lime tends to bond to these soils very easily. The stems of the plant will not be able to hold the plant up and will exhibit a white brown in between the veins of the leaves when having too much calcium. Also having to much potassium and or nitrogen will cause a calcium lockout.

    Problems with Calcium being locked out by PH troubles

    Improper watering, (most common cause), very acidic soils with excessive potassium, excessively dry and or wet soil. Lack of calcium in the soil results in the soil becoming too acid. This leads to Mg or Fe deficiency or very slow stunted growth


    Calcium gets locked out of soil growing at ph levels of 2.0- 6.4 Calcium is absorbed best in soil at a ph level of 6.5-9.1 (Wouldn't recommend having a ph of over 7.0 in soil) anything out of the ranges listed will contribute to a Calcium Deficiency.

    Hydro and Soil less Mediums

    Calcium gets locked out of Hydro and Soil less Mediums at ph levels of 2.0- 5.3 Calcium is absorbed best in Hydro and Soil less Mediums at ph levels of 5.4-5.8 (Wouldn't recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a Calcium Deficiency.

    Solution to fixing a Calcium deficiency To fix a calcium deficiency you can treat by foliar feeding with one teaspoon of dolomite lime or Garden lime per quart of water, Or Any Chemical/Organic nutrients that have Calcium in them will fix a Calcium deficiency. (Only mixing at ½ strength when using chemical nutrients or it will cause nutrient burn!) Or you can take crushed up dolomite lime or garden lime in a gallon of water and water it in the soil. 1 to 2 teaspoons per gallon of water, which will be slow acting. Garden Gypsum, which is medium absorption. Limestone, which is medium absorption, Rock Phosphate and Animal wastes which are both medium/slow absorption. Note: Caution when using gypsum to an already acid soil (pH that is less than 5.5) can have a very bad effect on different types of plants by effecting the absorption of soil aluminum, which is poison to plant roots.

    Now if you added to much chemical nutrients and or organics, (which is hard to burn your plants when using organics) you need to flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients.

    Edit: for your root slim I use you might have noticed I'm a user of Nutrilife's products like the "A" "B" "C" Powder and SM90
  2. #2 Oz (therealone), Feb 15, 2011
    Last edited by a moderator: Feb 15, 2011

    The ideal 5.6 pH you cite for hydro differs from the nutrient tables I've seen that show 5.8 to be optimal. At 5.8, you're essentially only locking out Zn. Below 5.8, you're locking out Mg, which I don't believe is a nute you want to be deficient in.

    Also, not sure if your 1,000-1,400 ppm range is on a .5 or .7 conversion scale, but I'm on a Bubblegum grow that I started at 1000 ppm at a .5 conversion and they've been burning. I'll be flushing and dropping to 400 ppm tomorrow, which I recently saw cited as a "burn threshold" for White Widow and Bubblegum. Admittedly from a single grower on a different forum, but I can say for myself that, at least at a .5 conversion, I've gotten some burn on most of my strains (one is a wicked little, sativa-looking thing I grew last time from anonymous bag seed and cloned for this grow; it gave me about 5 oz off the single plant, burn and all!). The single Juicy Fruit plant I'm growing seems quite a bit more tolerant, but the Bubblegum doesn't like it at all.

    I started my first grow at 1100-1400 ppm and had burn. I stepped it down a bit to around 1000, but the burn pretty much persisted - a full flush probably would have helped. I'm convinced that, at least at the .5 conversion, those levels are simply too high. I couldn't imagine growing anything at 1800 ppm, but........I'm still new at this.

    As a bonus, I'll start saving on ferts. ;)
  3. fuck, thanks for the info... might help me stop frying my horrible plant
  4. hahahaha... seen alot of this today... 5-11-2006... another coffin, but you might have saved my ass with my plant.. thanks again... im in full flush right now.. even though im only lowering ec from .8 to .5... i don't care.. i am tired on nute burn

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