optimal ph, nute lock, organic growing

Discussion in 'Growing Marijuana Indoors' started by gr0wer, Jun 10, 2003.

  1. I just recieved my ph meter today, I put my plants in bigger pots today and i tested the soil it read 6.6-6.9 is this ok? I heard 6 is good for soil but whast optimal?? And when high and low, does nute-lock occur? and I used compost dirt from my backyard for the transplant should i use ferts still, use a weaker ratio, or cotinue with my normal ferting same strength. And i tested my liquid fert and its around 5.7ph so shold i think of changing the ph of the fert so it dosent change the ph of the soil as much?
  2. whats your water ph and whats the ph of ur water mixed with ur fert.? or is it 5.7 by its self?
  3. how often do u fertilize? and how much?.....
  4. HIGH All, 6.8 is optimal for soil.

    Here's the Nutrient Availability Chart. For soil it's the left one and for Hydro it's the right one.

    When useing compost make sure it's been composting for at least a year. Useing soil from outside will invite those little nasties that acompany soil from the outside world.

    Attached Files:

  5. Thanks unoit for the chart, your the man. It will be handy if i think I ever get nute lock.

    I water once a week with 1/2 strength 10-10-10 and my last watering i steped up to 3/4 strength 10-10-10. I didnt test the ph with water, just straight fert. I will test that next time i water my plants. I just realized today thet thie one plant still has milky green leaf colors around some the vanes. Ive never seen it on any other plants ive grown or on the FAQs for deffeciencys. Prior to yesterday i believed the ph was off adn causing this. But now that i know it was good i m not shure. teh plant was like this since the first (real pointy leaf) node and every leaf has it. Could it just be genetics? I tried to take a pic but it dosent show in the pics because i dont have good lighting for pics, and my digi is a bitch at taking close-ups. I will attempt to get a good pic.
  6. Hi, this is directly from strainhunters (greenhouseseeds) website...

    Franco's tricks on pH

    There are many ways to grow good cannabis; the path each grower takes depends on knowledge, background, and philosophy. Those who dare to adventure off the beaten path, and keep curious about new possibilities, usually end up becoming really good growers. By trying new systems, new mediums, new feedings and new genetics growers can improve the quality and quantity of their output. Due to the illegal status of the plant, there has been relatively little scientific research on how to grow cannabis. On the other hand, there has been abundance of practical experience, as cannabis is one of the most cultivated plants on earth. Trial and error has been the traditional way of learning for the large majority of growers, and only in recent years, thanks to Internet and to cheap air-travel, the cannabis community has been able to link and to exchange information, data and genetics at an unprecedented pace. This has resulted in an explosion of the cannabis industry in general. Soil, hydroponics, coco fiber, aeroponics, organic feedings, synthetic feedings; each system has its positive and negative sides, and each can deliver great cannabis, if done properly.

    Of all factors that determine a successful crop the most important are: air, light and feeding. And for feeding intake, pH levels are crucial for optimum results.
    A small minority of growers has completely organic operations (meaning they use soil collected from forests, use predators to fight pests, and make their own compost exclusively from organically produced food) where controlling the pH of the watering solution should be done exclusively using lemon juice (to lower the pH) or limestone (to higher the pH).

    But most growers use some form of synthetic feeding, so they don't mind using nitric acid or phosphoric acid to lower the pH of the feeding solution, and calcium carbonate to increase it. Most growers need to lower the pH of their feeding solution; it is actually rare to have to increase it. The difference is in the stage of development of the crop. During vegetative growth, nitric acid works best, while during the flowering period phosphoric acid is the most indicated. This is because of the binding that happens with Nitrogen or with Phosphorus already present in the feeding.

    But the question always coming back is: what's the right pH?
    The answer is easy, jet complicated. The easy part is: safe levels are anywhere in between 5.5 and 7.0.
    Cannabis can successfully assimilate most of the nutrients needed when the pH is in between these levels, especially if all other important factors (air, light, watering frequency) are at 100%.
    Of course, to optimize quality and quantity it is best that all nutrients are assimilated at the optimum moment. Therefore it is advisable to keep pH around 5.5-6.0 during vegetative growth, and to increase to 6.1-6.5 during flowering. This way the Nitrogen is best absorbed during vegetative growth, and Phosphorus, Potassium and microelements are best absorbed during flowering.

    Because of the different conditions and optimal levels, it is worth examining a few typical situations.
    In case of outdoor guerrilla growing, it is difficult to control the pH of the earth. The best is to make sure the soil does not contain too much clay. For the rest, the only control is trying to balance well the feeding solution. Best in these conditions is to start at 5.5 pH then move on to 6.5 during flowering, and up to 7.0 during the end of the crop. A high pH at the end will reduce the chance of bud-rot or fungus development.
    Indoors, it really depends on the medium and the strains.

    In soil, with most indica strains, it is best to start at 5.8 during vegetative growth, move to 6.2 during flowering, and end at 6.4 at harvest. With more sativa varieties it is advisable to start at 5.8 and then smoothly go up to 6.8 at the end of the flowering.
    In hydroponics, the trick is to remember that the pH of the medium tends to jump very high very fast. Therefore, it is best to stabilize the pH of the medium at 5.5 before starting the grow cycle, and keep it slightly lower than one would do in soil. Flowering can be done at 5.8-6.0, and the end of the flowering should be done at 6.2-6.3 for indicas, and 6.4-6.5 for sativas.

    In coco fiber the game is similar to hydroponics, while in aeroponics the pH should be stabilized between 5.5 (grow) and 6.5 (flowering) for perfect intake.
    Adjusting the pH at the right levels will ensure that even the microelements are absorbed properly, which will boost resin production. And will also ensure that the plants stay green well into the flowering, guaranteeing maximum surface available for photosynthesis when the buds are building up.
    During my career as grower, breeder and seed maker I met several growers that were able to produce the finest product without controlling the pH of their nutrient solution. But it was cases of serious natural-born green finger. The large majority of growers benefits from controlling the pH and applying the theory to the practice, while remembering that it is always useful to experiment and fine-tune the values to tailor the genetics and the unique environment.

    Franco – Green House Seed Co.
  7. Equinox thanks for sharing that info very useful. :)
  8. no worries mate.. i've seen what greeenhouse seeds can do & the fact that strainhunters have experienced all types of growing environment all around the world.. i have found it to be exceptionally useful because i'd never even dreamed of going as low as 5.8 in soil... but it works & very well :smoke: glad i could help
  9. In peat based soil if you maintain 6.5 ph and in hydro or, coco 5.8 you will be covering all bases for nutrient uptake with no lock out.
    It is ok to fluctuate your ph .3 up or down but maintaining as close as possible to 6.5 or, 5.8 for the most part of all phases of a grow assures the plant has every available nute offered.....
  10. #10 Equinox117, Aug 14, 2012
    Last edited by a moderator: Aug 14, 2012
    yep... which is why i do it exactly to strainhunters guide.... 6.5-6.8 is mainly for sativa's in flower.... u want 6.2-6.4 for indicas... it works much better than a 6.5 as i have done 6.5 for the past few years but now having much less failures with a lower ph (using LED & Plasma)...

    P.s. I use bioterra pro plus... with biobizz nutes... temps 30-32c in day & 24-29c at night...
    humidity = 40-50% day... 60-80% night.... 26.7-33c is optimal for LED.. any lower n plants dont grow cuz moisture dont evaporate / get absorbed properly.. any heat producing bulb would be 21-29c..

    oh & i just realized anyway this is an organic thread... u dont need to ph adjust for organics... it just has to be within the 5.8-6.8 range after adding nutes... oh & the rumours about chlorine damaging the plants isnt exactly true either.. but then again biobizz is a dutch company & they made it to deal with hard water... sorry a bit side tracked their.. its like i was just thinking but typing at the same time without acknowledging i was typing lol
  11. "organic" growing is not supposto require phing

    other then that refer to chart posted by Unoit
  12. Yea...I can agree with 6.5-6.8 and never new of a different ph for sativa/indica strains. Good to hear from growers who have tried and proven the method...Kudos....:)

    In an organic grow their is no need to ph as long as you have a good quality of compost and amended the soil.
    Some plants, not necessarily MJ (tomato)respond well when chlorine is present as it is considered a nutrient.
    It is not bad to use tap water for seedlings, as a small amount of chlorine from tap is good to kill pathogens and help prevent damping off.

    Reason I don't use water with any chlorine for older plants(transplants)is that chlorine will lock out mg as will to much calcium.
    Chlorine will kill good bacteria and fungi which is not good in organics as we depend on the microbes to feed the plant.
  13. can u show the scientific evidence on this... oh u cant cuz there is none regarding chlorine & tap water.. but then again if u are in america it could be different... in uk our water companies test the chlorine they put in the water on plants & had no negative effects
  14. Yea... It's considered an important micronutrients for the photosynthetic reactions involved in the production of oxygen.
    I still have a hard time wrapping myself around this being a good nutrient for plants as we have been schooled that we should use de chlorinated water for plants.
    If you think about it oxygen is what kills bacteria but, never related chlorine to this but, in small amounts only....
    lol I grow old school and will always de chlorinate my water no matter what with the exception of seedling at small amounts found in city tap water....

    Here"s a read on that:

    Study with tomatos and the use of chlorine.
  15. Chlorine DOES kill your beneficial bacteria in an organic grow.

  16. You can also use nutrients to vary the pH - many nutrients have a pH up or pH down effect if you need it to change. Limestone Powder is great for balancing pH based on what way you need to move it. Here is an example Limestone Powder | Kelp4less
  17. just to give a heads up, do not go above 6.1 in hydro

    P, Fe, and B get locked out above 6.1, and P is especially essential for flowering, which directly contradicts what Franco is saying right there

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