the issue with Lucas formula

Discussion in 'Hydroponics / Aeroponics' started by DrGhard, Sep 4, 2017.


    DrGhard Active Member

    While I find the Lucas formula good for sativa-dominant plants (ie fast growers and heavy feeders), when using it with light feeders plants (either whole breeds or particular individuals of a breed) it walways ends up in nitrogen deficiency. This becomes particularly evident when using high intensity lights with UV component such as COB LEDs

    I believe this happens because the 5ml micro/10ml bloom (per gal) formula supposedly to be used in veg is too strong for certain strains at the earlier stages of growth. however the N in diluted formulations (1/4 and 1/2 strenght) is not enough to sustain balanced growth.

    so my suggestion for early veg stages of light feeder plants is to switch to the 3 part formula. all the times, adding back "grow" fixed all the issues for me
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    JDMase Well-Known Member

    I use floranova bloom and followed the lucas formula, I also bought the veg for when N looked deficient and that also remedied the loss of N found in veg for me with some strains. Usually only fed with it for a few feeds and then switched back when the plant looked healthy again.
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    rkymtnman Well-Known Member

    incorrect. 5/10 is for low light situations. fluoros etc.

    8/16 is Lucas
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    DrGhard Active Member

    yes, but also is suggested to use this formulation in veg. still the issue remains: for light feeders will cause nutrient stress, and at the same time fail to provide enough nitrogen.

    SwitchHitter Active Member

    The problem with this solution is simplicity. Simple in = Simple out

    It's the difference of quality that matters. Not the 5% of your profits in cost. Such a strange thing, to not use a nutrient that a company developed for specific purposes. Like people not using additives because they never know how to adjust base to accomodate. base nutrient grows make for weak smokes

    rkymtnman Well-Known Member

    by whom? Lucas is 8/16 for veg and bloom

    rkymtnman Well-Known Member

    you can also use maxibloom, floranova bloom and floraduo all in the Lucas formula.

    i'm using maxibloom as we speak. no nute stress and no deficiencies.

    DrGhard Active Member

    yes but that would defeat the purpose of Lucas formula isn't it? :D

    one could just use the normal GH 3 parts and have the same (no nute stress and no nute deficiencies) hehe

    PS: also the FloraNova contain organics iirc. not a very good choice for DWC when you have temp issues like i do :D

    rkymtnman Well-Known Member

    how so? lucas is just a n p k ca mg ratio for cannabis. you can even use other brands to get the same ratios.

    i'm using the maxibloom this run for that reason: i'm trying some GH waterfarms and didn't want to use floranova cause of the organic aspect. some HTH pool shock too to prevent root rot.

    and if you look at the GH feed chart for the 3 part, late bloom is lucas. 7.5 micro, 15 bloom if i remember, no grow.

    be4meliz Well-Known Member

    I use Gh 3 [email protected] 3/4 strength until 1/2 way into veg.(plants 1 1/2-2 ft,) then switch to Lucas after res. change thru flower and adjust based on EC/PPm -some feed more than others, so 5/10,6/12,8/16. Have never had burn or defencicies in 2 years.
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    Airwalker16 Well-Known Member

    Recirculating-Nutrient-Schedule-custom-sm.jpg this has treated me so well in rdwc. I follow it to a tee.
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    DrGhard Active Member

    yes, same here. just gave a try to the lucas for a couple of growths because i ended up without floraGro hehe

    in the end as @rkymtnman says is all about finding the optimal NPK ratio, and i feel that Lucas alone does not cut it, even as "entry level" formulation that supposedly is easier to use.

    i find it easier to just adjust npk and ppm on the go than dealing with the issues of lucas. in the end you just need basic math capabilities
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    rkymtnman Well-Known Member

    what i like about it is that i grow different strains each grow. it gets me close enough where all of them are healthy. but if i had a certain strain that i grew all the time, i would definitely want to dial in my nutes for that particualar strain.
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    HydroRed Well-Known Member

    I heard the same about the organics (and its thick as shit too), but wasn't able to find anything concrete either way. I used it in a flood and drain with a 27 gal res with no chiller & no issues. I also added H2o2 so if there are some organics in it I killed those shits off real quick. Cant say I'd use it in an emitter or drip system though. If you do find yourself able to run it, Im sure you wont find any N shortages during flower. That shit is potent.

    ChaosHunter Well-Known Member

    I've been a big Lucas/KISS Maxibloom grower for a long time, often putting full sample lines up to it. Mega Crop by Green leaf nutrients is blowing the lucas/Maxi out of the water so far in every aspect and its canna specific. I think once grower get this in there hands it will become the new standard over the Lucas/KISS.

    With most nutrient lines they are not canna specific as mentioned above.
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    DrGhard Active Member

    this sounds interesting but again it contains kelp extracts and chitosan-like components. whole those are great for plant growth stimulation, being organic compounds they can trigger harmful bacterial growth if temps go out of control

    theinhibitor Well-Known Member

    I find most people over feed. To the moon.

    I hover around 180 - 200 ppms in veg, starting with distilled water (steam distilled). For clones, its even less around 100 ppms.

    In bloom I hover around 350 - 450. Plants that I find are heavy feeders in hydro, usually produce more resin than crystals and are more suited for outdoor growing (so I pop them into the green house). I actually dont find sativa dominant strains to be heavier feeders. I think it depends on the strain and since basically nothing these days except from landraces found in India/Jamaica/Afghanistan/Thailand/Mexico are hybrids, I would not go by any preconceived notions on feeding before analyzing a few plants.

    The pros of low ppms:
    1. Your bud smokes better - way better
    2. You will produce more crystals (higher THC count)
    3. You will have longer flowering periods - look below at 8 weeks, everything still green and vibrant
    4. You will win cannabis competitions with ease (2 medals now, won my first in 2013)
    2014-01-02 02.10.35.jpg
    2014-01-02 02.09.04.jpg

    The cons:
    1. You may get slightly less heavy buds. Ive only analyzed this a few times, but the outcome with high vs low was like 1.9 lbs to 2lbs same strain, system, etc. And the saved cost of the nutes makes more than up for this.
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    DrGhard Active Member

    This! and the problem of the lucas formula is exactly this. to get enough N for low feeders you have to have insane ppms from the rest of the nutrients.

    i must say i was one of those DWC heavy feeders, but i also discovered my EC meter was set with the correction 0.5 scale, instead of 0.7. so when i tried the lucas formula at full strenght i didn't even get close to the 1300 ppm, but around 900. that was because of my meter correction factor.
    Without knowing that i was pushing ppms to 1300, which would equal to more than 1500 with a regular meter. needlees to say plants were getting stressed (although i was growing a Sannie's Jack F7, which was an incredible heavy feeder).

    now i'm running a white widow in full bloom at 450 ppm. and like yours everything is green at week 6 of flowering. the idea that you need your leaves to yellow in flower is huge BS, and just an indication of stress. around week 5-6, particularly in DWC, plants have a huge drop in nutrient usage, which you can see if you monitor ppm daily.
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    DrGhard Active Member

    i also disagree with that. a stressed plant grows less, period. so if you overfeed throughout the whole growth cycle you will have less yield most likely

    ChaosHunter Well-Known Member

    Genetics, light, environment and grower talent all play a key role over nutrients. A good grower can take any nutrient lineup and do well. The plants, different strains and phenos will tell you what they want more than a feed chart or meter. These are weeds that grow wild in a ditch not a Orchid or magical unicorn.
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