Lucas formula - what strength? overfeeding?

Basic Growing Info
#21

in cannastats it says Lucas formula 7.5-15 provides a profile of 122N-99P-171K-68MG in ppm. https://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm Do you know how much N you can give?

On that page they write in veg you can give like 250-350ppm of nitrogen. In flower they say only max 100. But my guess is you still can give a lot of N in the first two weeks of flowering (stretch).

What is your experience in regards to amount of N in you fertilizer?

I am looking for a cheap all purpose mix.

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#22

do you use 5-10. Dont you have nitrogen deficiency in veg?

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#23

Never. :slight_smile:

Granted I stopped using GH a little while back, but I used the Lucas formula for a few years. 5-10 + calmag.

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#24

If youā€™re really concerned about it you can do 6/9 in veg and 5/10 or 4/11 in flower depending on what the plants like. Beyond that, it really isnā€™t much more complicatedā€¦

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#25

You donā€™t want to mess with the recommended ratios of nutrients from any company. Always keep the ratioā€™s the same.

2-4 , 4-8, 5-10 okay

1-3, 3-9, 4-11 not recommended.

To OP, literally just stick with 5-10. The plants will tell you whatā€™s needed. (Then if you have to adjust, you read the plants and do so.) Thereā€™s not way to know for sure, for every plant. You could have a nute heavy strain, you could have a sensitive strain. Generally speaking 5-10 will take care of most everything.

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#26

Well Danny I respectfully disagree, I think the whole point of this thread is that OP is exploring options and learning. I appreciate your desire to offer a simple solution, but you donā€™t have to be dismissive of something I said based on years of success.

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#27

sorry you took it that way. Didnā€™t mean to step on your toes.

The advice Iā€™m giving comes from well over 40 years of growing experience at a very large scale, true ogā€™s in the game. The thing with the actual nutrient ratios comes down to a science, it comes straight from the nutrient companies.

Iā€™m not saying youā€™re wrong by any means, thereā€™s no right or wrong way to grow. Doing what works best for you is the best way to do things. I was just sharing what Iā€™ve learned and information Iā€™ve been handed from those with an insane amount of experience.

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#28

In coco though there is the time tested head formula of 6-9ā€¦ Strain dependent supplement Epson 1gram per gal. But ya for SOP its easier and sits in the sweet spot at 5-10 1.2 t o1.4 ec depending on time of yearā€¦
My spin on it is I add 5mil calcium in the form organic chelated plant amp by cutting edge to good effect.

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#30

did anybody of you have a nitrogen deficiency with lucas formula or ironhead method?

#31

Guys, do you prefer topping off or addback method? How big is your reservoir? How often you change the nutrient solution completely?

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#32

you should only mix as much nutrients as you know you will use within a 7 day period. You can also optionally aerate that res. If you can deal with mixing nutes more often, fresh is best - but not necessary.

Unless youā€™re in hydro, you donā€™t really need* to top-off. In soil you can easily just refill the container. If there is a little nutrient solution remaining in your res, take that into account while refilling it and adding nutes again.

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