About to start flowering

Discussion in 'Growing Marijuana Indoors' started by mrog1718, May 22, 2010.

  1. I am planning on flower my plant some time tonight. I have one plant under 250 watts of cfls, in a bubble bucket. I have been using the Lucas formula for my nutrients, my question is should i flush out my system and start with all new water and nutes? or can i just add a the difference in the nutes? any other comments or suggestions are welcome this is my first time flowering.

  2. bump any help??
  3. Yes, always change your water when you switch from veg to flower. Now you'll be using 0-8-16 instead of 0-5-10
  4. change half your CFLs to 2700k if you haven't already. Then change them all after the plants stop producing new vegetative growth (after preflower -- 2-3 weeks in).

    Your results will be far better.
  5. I've never grown hydro, so dont take this is fact, I'm merely spreculating.

    To me, it seems to stand that by slowly diluting your nutrient solution from grow, to pure h20, to bloom, that you help ease the plant into flowering and reduce stress. My thinking is that the plants hormonal switch or what not, is not instant, so the nutrient switch shouldnt be. Much like the light scedule.

  6. There's 2 ways to use the Lucas Formula. The first is add-back, where you add full strength nutes to your reservoir when ever you "top off".

    The other method is to start with full strength nutes then "top off" with plain water.

    Having run both these Lucas methods (not to mention others), I've never had a problem with stress from moving from veg to flower :smoke:
  7. Word. That's the kind of first hand experience i like to hear about. I grow soil, and like to wean off of veg and then into flower. I've noticed less stretch, thicker stems, and somehow, denser bud. All part of dialing into the strain yanno?

  8. should i do this at the same time i switch to 12/12 or leave it at 24/0 and switch to 12/12 when they are all 2700k
  9. This is WRONG (Not saying that disrespectfully). There is no difference in veg and flower with the Lucas formula. The Lucas formula is 0-8-16 for the ENTIRE grow.

    0-5-10 is for CFL lights only, and 0-5-10 would be used for the entire grow under CFL.

    The only change is if you have a strain where seedlings or clones can't handle full strength, you can cut it in half (0-4-8) for the first 2 weeks. But other than that, if you are running the Lucas formula correctly under HID lighting, you are using 0-8-16 for the whole grow, veg and flower, and if you use the add back formula with nutes, you need no res changes for your entire grow.
  10. :smoke:

    General Hydroponics Flora Series Feeding Strategy - Lucas Formula

    G-M-B (Grow-Micro-Bloom)
    0-5-10 - For Vegetative cycle (18/6)
    0-8-16 - For Flowering cycle (12/12)

    The numbers above indicate the number of milliliters (ml) of Flora Grow, Micro or Bloom formulas that I use in one gallon (US Liquid) of nutrients.

    You will notice I dont use any of the Flora “Grow” formula, do not need to, the Flora "Micro" provides plenty of Nitrogen.

    There are two ways to work with this formula:

    1. Top off the reservoir daily using a pH corrected water solution as required to maintain full reservoir level. After adding back an amount of water equal to the amount of your reservoir capacity you should change the reservoir and put in fresh solution.

    2. Top off the reservoir daily using a pH corrected 100% strength nutrient solution as required to maintain full reservoir level. Continue to use this nutrient solution without dumping the tank unless the PPM rises above acceptable levels.

    Between vegetative and flowering cycles you should dump your nutrients, then flush (possibly with Clearex) to remove salt buildups, then change to the other feeding program. Always shake your GH nutrient bottles before using them!

    For young plants, just transplanted into the hydro setup, give them 50% strength nutrient mix to prevent overfeeding them while their young. Gradually bring up the mix to full strength as they grow over the next few weeks or so.

    The lucas formula is normally intended for use with RO or near 0 PPM water.

    NOTE: The Lucas formula eliminates the need for Epsom salts to correct (Magnesium) Mg deficiencies in most normal feeding programs recommended by manufacturers. Cannabis needs a lot of Magnesium to thrive.

    The Flora Micro is providing the Nitrogen and the Magnesium in the proper balance, thus there is no need for the Grow formula and little or no room under the maximum acceptable ppm limit of 1600 @ 0.7 conversion.

    Calculated EC/TDS levels:

    EC microsiemen:
    0-4-8: 946 µS
    0-5-10: 1184 µS
    0-8-16: 1894 µS

    TDS @ 0.5 conversion:
    0-4-8 = 473 ppm
    0-5-10 = 592 ppm
    0-8-16 = 947 ppm

    TDS @ 0.7 conversion:
    0-4-8 = 663 ppm
    0-5-10 = 829 ppm
    0-8-16 = 1326 ppm

    Addback Calculator - (For Advanced Users)

    Say you were running the 0-8-16 formula, at 0.7 conversion with a 22 gallon res. When you first fill it up, your ppm will be around 1330.

    Now you have been growing for a week, and some of the water has been taken up by the plants, some has evaporated, and now your res is at 947 ppm. You need to get your ppm from 947 to 1330. Here is the equation:

    ((target - current) / target) * 8 ml per gallon * res gallons = Flora Micro (ml) double this figure to get Flora Bloom (ml)


    ((1330 - 947) / 1330) * 8 * 22
    (383 / 1330) * 8 * 22
    0.3 * 8 * 22 = 53 ml Flora Micro

    53 ml Flora Micro, double that and you get 106 ml Flora Bloom. So 53 ml Flora Micro and 106 ml Flora Bloom to add back to your 22 gallon res to get you from 947 to 1330.

    Using Hard Water GH Micro

    I had been experimenting with using the Hard water Micro as a substitute for the normal Flora Micro, this to account for my hard 350 PPM water and the lack of a large enough RO filter at the time. It has worked well for me. I just kept my reservoir below 1150 PPM @ .5 conversion and its all good.

    One tip - do not pH down this stuff, the hard water micro will drop pH gradually over the next 24 hours, for example I mix up a batch, it is at like 6.2, the next day, its at 5.6-5.8 after running in the system for a while. If I pH downed that to 5.7 before putting it in the system, it ended up as low as 4.8-5.2 by the next day.

    My conclusion, the hard water micro was buffering the alkaline crud in my water, it just doesnot do it ASAP fast like the phosphoric acid.

    Using GH Flora 3-part liquid nutes:
    0ml of Grow, 8ml of Micro & 16ml of Bloom per gallon of RO.

    Lucas Method(s)
    The method you use to maintain the nutrient levels in the reservoir, after you've mixed them, depends on the equipment you have & your level of understanding. There's a simple change-out method & an add-back method. Both are very successful with the add-back having a higher yield but also being a bit more complicated & requiring an EC/TDS/PPM meter of some sort. I highly recommend anyone new to the community to use the simple change-out first & to only use pH drops or a pen for it. It will allow you to concentrate on the plant more.

    Simple Change-out method
    This simple method for using the Lucas formula only needs pH drops or a pH pen to be successful with. Let's use a reservoir that holds 10 gallons of mixed nutrient solution as our example.

    Using GH 3-part: 10 Gal

    Add 80ml of Micro & mix it in well.
    Add 160ml of Bloom & mix it in well.
    Adjust pH to 5.2

    Mark the level of the nutrients in your reservoir. Keep the level of the reservoir the same by adding RO water & keep track of how many gallons you're adding.
    Once you've added back the original number of gallons you mixed (in our case, 10 gallons) it's time to dump the reservoir & mix a fresh batch of nutes.

    That's it! (wasn't that simple? )

    You'll notice that I didn't mention adjusting the pH again. That's because you won't have to. All you should do on your first grow is check the pH daily & mark it down. Keep track & see the pH swing as it goes up & down through the life of the res. Watch the plant too & write down any changes you see in growth. If your pH bottoms out below 4 you have root rot or some other issue, adjusting your pH won't help.

    !!!!!!Note On 400w HPS & Lower Power Lighting: You May Find That Your Plants Don't Have Quite Enough Light To Grow Properly In A Full Strength Solution. Start With 0-5-10. Increase To 0-6-12 If Your Ph Steadily Rises & Goes Above 6.1. Keep Adjusting The Strength Until Your PH Swings Between 5.2 & 6.1 Without Going Past Those Points. Make Sure You Write Everything Down So That Once You Figure Out What Your Plants Like For Your Situation You Can Mix That Strength To Start With The Next Time.
    Just Remember That If Your PH Goes Up Out Of Range Over Time & Doesn't Come Back Down, You're Not Feeding Enough. If Your PH Slowly Goes Down & Down Below 5.1, You're Feeding Them Too Much. (This Is Of Course Assuming That Everything Else In The Garden Is Good.)!!!!!!

    This Is Not Mine

  11. I just put my baby into flowering. I used the 0-8-16 as said in the last post. I am under clfs so I don't know if this is right but not much I can do now. I am going to top off with fresh water until I need to replenish nutes. Hope all goes well. well see what happens

    thanks for all your responses
  12. Switch to 12/12. Your plants will start to sprout crazy branches everywhere (if indica strain... not sure if pure sativas do it), and make a few little preflowers. They will also grow much taller, and in a very short time period. Then they'll pretty much stop growing up and you'll see buds start really forming. That's when you switch to all 2700K. normally it takes 2-3 weeks.

  13. I just switched my plants to flowering. and i put in all 2700k lights. Is it too late to switch to what you said? and can anyone else verify this I've never heard of this before.

  14. Once again, in the most respectful way I can say it. This is WRONG.

    From the man himself.
    "btw, before I blaze ahead, I dont recommend 0-5-10 as a veg formula actually, I only recommend it as a low light formula.."

    From this thread

    Ask Lucas - Page 2 - Cannabis-World

    I do not spread false information, I only try to help.
  15. Bbadaxe. I am using CFL's so 0-5-10 is good for me. But i was unaware of that. I switched to 0-8-16 now and after much reading I don't exactly understand how i should top off my reservoir. Do I top it off with just pure water? not Ph corrected and no nutes, until I top off with the amount of water that is in my reservoir? or can I just top of with Ph corrected water as well as with full strength nutes?
  16. #16 BadAxe, May 25, 2010
    Last edited by a moderator: May 25, 2010
    Read that thread I posted above. Its all Lucas himself talking about what he knows. If you want to do no flushes, as I am doing (at least if everything goes according to plan) there is an addback formula for figuring out how much nutes go back in. If you follow this formula and your readings stay on point, you do not need to flush your res for your entire grow.

    So it would go like this. (You should have your initial ppm or EC readings recorded) Also assuming RO water is used.

    1. Add back however much water it takes to get you to full res.
    2. Take a ppm reading.
    3. Using your starting ppm and your just tested ppm, plug into the formula and that will tell you how many nutes to add back to get back to your starting target ppm. Take the total number you get from the formula, divide it by 3. 1/3 is the micro, the other 2/3 is the bloom.
    4. Drain a gallon or 2 from your res, and add nutes to this solution and mix to dilute (NEVER ADD STRAIGHT NUTES TO YOUR RES).
    5 Add that solution back to your res.
    6Take ppm and ph readings. You should be spot on.
  17. I do not have a ppm tester is there an easier way?
  18. Not that I know of to do it without flushing. With no ppm teter I hope you are using RO water? The Lucas formula can be run without a ppm meter if you are using RO water, might be a bit more complicated with hard tap water.

    Without a meter I would most likely use the add back of just water, and when you reach the total addback gallons that equal your res size, then I would flush and start over.

  19. Yea i figured I would have to flush. I just wanted to double check. And when you say just water should I Ph correct or not?
  20. Yes, PH corrected water.

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