Lucas Method, no grow formula

Discussion in 'Advanced Growing Techniques' started by weedies, Apr 11, 2007.

  1. Just seeing if anyone still uses this. I found it online and it seems to work great. I'm 16 days in my 2nd harvest and everything is going great. Just wondering if anyone had anything to say about this method. Why or why you like don't like it?


    I just like it because its just twice the bloom to the micro and thats it! Start rooted clones off @ 600ppm and raise it to 1400ppm slowly and stick them in 12/12 around the same.


    For those who don't know... This is what it is.... Taken from a random google'd site.

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    Lucas Formula

    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)

    Example:

    ((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. ---
     
  2. I use it, it works great.
     
  3. Rump since you use this when first transplanting your clones or seedlings into the hydro system did you use 0-2.5-5 (50% nutrient level) and then gradually move up. I know you only vegged for ten days thats why I asked.
     
  4. i am currently about 2 weeks in, using 0-5-10 for them, thought it would be a little much, but it never hurt the plants really so i just left it, i guess another 2 weeks and i will have it at full strength, maybe 3...i am going for not needing to change out the res, i have heard of some people going 3 grows without changing the water
     
  5. After I get roots from a cutting, I place it back in the aero cloner with 50% veg formula in 6" net pots. I don't put them in the bubble buckets until I see roots comming out of the net-pots. When they go in the bubble buckets they are at 100% veg formula.
     
  6. I've heard much about this lucas formula, I in fact use those 3 part nutes (My hydro store ran out of AN).

    What I am yet to see or find is an entire logged grow with pictures using this formula.

    Could you point me in the right direction please?
     
  7. Look at Rumples harvest pictures. He used the lucas formula.
     
  8. Look at either my current grow, or my last grow (the white widow one). The last one I was still in the learning process and made a couple of mistakes - most notably not using the Formula full strength under HPS. I still ended up with a pretty impressive crop at the end, despite the problems.

    My current grow is going so smoothly it's almost boring....which really isn't a bad thing :D.

    Also, check out Mr.Goodstuff's grow log. He's been away for a while :)() but his log is really educational and his grows have been pretty impressive.
     
  9. Wow, this is a great site. The ole Lucas formula, I havn't seen or heard this was still around in quite a few years.

    Yes, I have tried it sucessfully a number of times. The one issue I found is the constant adjusting of PH in the nutrient mix. It seems that the Grow is a key in helping stabilize the PH for the week r so you use that mix. As you all know, you should change out the nute soulution every 7 daze or so.

    But, when I did use the Lucas formula, it worked with no ill effects. The plant still grew healthy and produced well. Until you find that one strain that DEMANDS more nitrogen during both Veg and Bloom. Not all strains are created equal.

    So I went back to the str8 3 part, using the grow. What I noticed very quickly, was that the starins that I was using the Lucas method on, grew noticably faster and "lusher"
    In fact, my overall yeild went up. Now, I didn't just use the str8 3 part as per the directions, I did in fact run about half of what it is ssuggested to run for the Grow nutrient.

    Never had any issues after that and it's been 3 years.

    My 2 cents.


    By the way, anybody seen or have an old Plant Toubleshooting chart called the sick plant guide by Nietche?
    This was probably the greatest piece of reading Overgrow had posted.
     
  10. I also use this formula in hydro and soil with alot of added AN sups. with great results,never had one issue with it. Prolly should have done some plants using just the Lucas formula but i enjoy dosing so much i thought what the hell.Works for me.:D
     
  11. i am using the lucas formula for my grow, no additives or anything...starting with 0-5-10, and will be going 0-8-16 soon because he now reccomends full strength basically the whole time... the link is in my sig..check it out if our interested
     
  12. He only recommends full strength all the time IF you use HID,otherwise its 0-5-10 all the time.Unless he made another change.;)
     
  13. i am using 400 watt mh, and then switching to hps for flowering
     
  14. You're doing something wrong then. While it does take a couple of days after you set everything up for the pH to stablize, especially if you're using R/O or distilled water, once you get going the pH stays very stable. My pH drifts slowly downward - about 0.2 every two weeks or so. But that's child's play to correct.

    Uh, no, you don't have to change out the reservoir. That's one of the beautiful things about the Lucas formula, because it makes it so easy and low maintenance.

    Of course each strain is different. My White Widow grow ran at 1100ppm the whole grow, 1150 burned my leaf tips. My current grow is running at 1350ppm. But they both used the Lucas formula the whole way. You just have to be smart enough to watch your plants and make some adjustments to your nute concentration levels if needed.
     
  15. Well the flora grow micro and bloom is of virtually the same concentrations as AN grow micro bloom...

    in fact the only difference is in the Grow formula, in flora it's 3-1-7 and in AN it's 2-1-6

    the micro and bloom however are exactly the same. Alongside these nutes I also use virtually the complete AN range. I used the AN grow just fine and now the flora set too is going just fine... no pH issues, no nute issues (at least not since i changed the batteries in my truncheon, lol).

    AN live and breathe weed... and their products second to none, flora nutes are almost identical to AN. So why hasn't this same thing been done to the AN nutes? In fact the ratios should be exactly the same anyway.

    Personally though, i'll stick to the 3 part. works for me.
     
  16. Not sure why Lucas originally used GH products and not somebody else. However if you look at the Ask Lucas thread he's got going, there's a spreadsheet listed in his signature. You can plug in the nutrient profile of any other product line, and it will give you the right proportions to approximate his formula.
     
  17. I use it because Rumple uses it. I've always had great results...but I don't have a whole lot of experience either so just trust Rumple ;)
     
  18. wait, so if you use hid's what changes? You use the flowering solution the whole way through?
     
  19. yes. if you use hid's, use 0-8-16 from start to end.

    thats 0 ml of grow, 8 ml of micro, and 16 ml of bloom.
     
  20. Sorry to bring up a dead thread but I havent been on in a while. With clones is it still 50% in cloning period or just some super thrive with them sitting in water?
     

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