Does Lucas formula make sense? Ever tried it?

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Scientific

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Does Lucas formula make sense to you? Have you ever tried it?

Lucas formula: famous simplified nutrient mix (and its variations) of simply 5 ml of General Hydroponics FloraMicro and 10 ml of FloraBloom per gallon (no FloraGro), used for hydroponics from beginning to end of grow.

Liking to "keep things as simple as possible, but no simpler," and resenting the marketers and snake oil salespeople who seem to want to separate unwary growers from as much of their money as possible by trying to make them feel that they need a dozen bottles of expensive stuff, I thought it might be interesting to make things as simple as possible and try the Lucas Formula.

When I looked into it, though, two things struck me:
  1. I typically use a total of 1 to 6 ml of GH FloraSeries nutes per gallon. <edit> Oops, I was looking at my coco drain-to-waste notes. For DWC I use more like 10 to 15 ml total, though less at the beginning</edit>Lucas uses 15 ml per gallon and then keeps diluting it by topping of the reservoir each day until the amount added equals the reservoir volume (that is, you add another 15 ml to a 10 gallon reservoir after you have added 10 gallons of top-off water). That does dilute the mix eventually, but that first bath is really concentrated!
  2. Using just two bottles of a three bottle solution AND at the same level throughout the grow means nute levels aren't just way higher (into the toxic range for younger/smaller plants in my experience<edit>Again, I was looking at the wrong notes. 15 ml after the first couple of weeks is actually in a range I have used so not toxic. :P So I guess my concern is not customizing nute levels throughout the grow, the idea of which I always liked.</edit>), you also aren't adjusting ratios of N, P, and K throughout the grow.
Given all that, I'm curious why I keep seeing mentions of Lucas formula and how anyone could make it work well.

Any thoughts and (better yet) experiences with Lucas formula?
 
Yes. I used it on last years grow. Worked great.
 
I'll read your whole post later and give you some better insight.
 
You can start low 5/10 then 6/12 if plants are ok. Then raise to 7/14 I never went past 8/16. 8 ml micro per gal and 16 per gal of bloom. Lucas isn't a set formula. Just double the bloom. Hope I said all that right. Using the normal formula right now.
 
The Germinator said:
You can start low 5/10 then 6/12 if plants are ok. Then raise to 7/14 I never went past 8/16. 8 ml micro per gal and 16 per gal of bloom. Lucas isn't a set formula. Just double the bloom. Hope I said all that right. Using the normal formula right now.
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OK thanks. Good to know and thanks for the reality check.

Just for reference, here's a quote from Lucas himself (16 years ago!):
"I suggest General Hydro nutes at 0grow-8micro-16bloom in milliliters per gallon as the mix for established, 12" tall clones with well developed root systems. For smaller plants and newly rooted clones I suggest 0-5-10."​
 
There are 3 products from GH that mirror the original Lucas formula. The Flora Series - 8ml micro and 16ml bloom is the original and was later amended for coco to 6ml micro and 9ml bloom called the H3ad formula. Flora Nova Bloom with no grow at a rate of 8ml per gallon. And lastly - MaxiBloom with no grow at a rate of 7 grams per gallon of tap water - called the KISS method.

I have used all three and they all worked very well. I now use MaxiBloom only because it is inexpensive compared to using the Flora or FloraNova products. I use MaxiBloom from start to finish and the only additive I use is Silica Blast - I never have a deficiency.
 
MickFoster said:
There are 3 products from GH that mirror the original Lucas formula. The Flora Series - 8ml micro and 16ml bloom is the original and was later amended for coco to 6ml micro and 9ml bloom called the H3ad formula. Flora Nova Bloom with no grow at a rate of 8ml per gallon. And lastly - MaxiBloom with no grow at a rate of 7 grams per gallon of tap water - called the KISS method.

I have used all three and they all worked very well. I now use MaxiBloom only because it is inexpensive compared to using the Flora or FloraNova products. I use MaxiBloom from start to finish and the only additive I use is Silica Blast - I never have a deficiency.
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Great answer. Thank you!
 
I'm using a spreadsheet to compare feed charts and thought I'd post this side-by-side view FWIW.
The numbers are milliliters per gallon (3.8 liters).

Shown are:
  • General Hydroponics' feed chart
  • Nebula Haze's diluted version of GH's feed chart
  • Lucas's feed chart "for established, 12" tall clones with well developed root systems"
  • Lucas's feed chart "for smaller plants and newly rooted clones" (by which he probably didn't mean seedlings, BTW)
NuteComparison.PNG
 
You have to keep in mind ppm when using the formula. A seedling wouldn't need 1000 ppm so I'd use like 2 micro and 4 bloom per gallon then check ppm. Then adjust from there. I add 2.5 ml per gal of kool bloom liquid too. Starting in bloom. Again. Ppm is the key to knowing if you've put to much. IMO.
 
I personally don't like it but that doesn't mean you won't you use double the micro and no grow so to me it just makes more sense to follow directions
 
The Germinator said:
You have to keep in mind ppm when using the formula. A seedling wouldn't need 1000 ppm so I'd use like 2 micro and 4 bloom per gallon then check ppm. Then adjust from there. I add 2.5 ml per gal of kool bloom liquid too. Starting in bloom. Again. Ppm is the key to knowing if you've put to much. IMO.
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That makes perfect sense now that you mention it. You don't have to just blindly dump fixed quantities into the res but can use smaller amounts at a 2:1 ratio, monitor PPMs, and increase the dosage if you need/want to.

Thanks again. :thumb:
 
I don't even own a ppm or ec meter. I know that 7 grams of MaxiBloom is full strength and I adjust down depending on the age of the plant. I never have a discolored leaf.
 
bignugz420 said:
to me it just makes more sense to follow directions
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Yeah, I imagine General Hydroponics has some major league crop scientists on the payroll who have done a lot of work in lab and field to refine both product and process (and that maybe they roll their eyes when they see consumers altering their carefully concocted feed schedules?).

What got me thinking about doing this was watching the level of the FloraMicro and FloraBloom bottles decrease twice as fast as the FloraGro, even when following directions. It just seemed logical that maybe a method that just used the N in FloraMicro could work.

The down side of using the Lucas formula is that you have less control over the ratios of nutrients than when you use all three bottles (but apparently that's not all that important, since the simplified Lucas dosing schedule seems to work for people).
 
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