Help me with Lucas Formula and PPM in soil (or coco)

anomolies

Well-Known Member
+Rep for anyone that helps.

I'm currently using Miracle Grow (along with all the other additives in SPL1s formula) plant food for veg, thinking about replacing with Lucas Formula...

at the same time I'm just beginning to understand PPM. (though not so well.. and I still don't have a meter... saving for a Truncheon).

So I have a few questions... read on... (questions at the end)

I use a R.O. 5-stage filter, but the filters haven't been changed since 2006 so I can only guess at its effectiveness.

Regarding the Lucas formula (took this off "The Lucas Formula" on rollitup):

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
I also found this table suggested by someone around here:

Seedlings 50-150 ppm
Un Rooted clones 100-350
Small Plants 400-800
Large Plants 900-1800
Last 1-2 Week of Flowering Water!
I think I've heard of people running 3000 ppm in their reservoir with no problems?

However, I'm doing soil (also doing a seperate coco grow),

I am wondering if my PPM will be within the acceptable limit if I'm adding non-plant food and other additives.

These are the other things I'm adding per gallon (SPL1's formula):

1/2 tsp Dyna gro pro-tekt
1/4 tsp Humboldt Nutrients Flavorful (fulvic acid)
1/4 tsp Humboldt Nutrients HumBolt (humic acid)
1/4 tsp Humboldt Nutrients Prozyme
1 tsp Humboldt Nutrients Ginormous (during flower)
1 tsp Humboldt Nutrients Honey ES (during flower)

Sometimes I add Liquid karma at 1 tsp per gallon as well because I get bottles of these for free.
+Voodoo juice 1st/2nd week of veg.

Is this too much? Is it possible to estimate my PPM from this information assuming my R.O water is 0 ppm?

I want to replace Miracle Grow and still be able to use all my other additives because I already spent the money.


edit:

damn.. maybe I won't use LF afterall.. cus I did more reading and found out it's not meant for people who want to veg longer?
 

slomoking13

Well-Known Member
I've used lucas formula with hydro and hempy with 100% perlite but i don't think it would be ideal for soil, especially once you start using a lot of additives with it. The only reason i used lucas was because there weren't any easy ways to go all organic with hydro and i wanted to try growing in water. The only thing you have to be careful with when vegging longer with lucas is adding cal-mag to make sure you don't get magnesium def (you can always raise the amount of ferts if the plants need it, just always maintain 1-2 ratio between micro and bloom... for examply instead of just 5-10 and 8-16, you can raise to 6-12 and then 7-14 as you go). You will definately want new RO filters and a ppm/combo meter if you plan on running lucas. There are better options when it comes to soil and there are a lot of good coco specific nutrients out there if you are leaning in the direction. Also, 3000 ppm will most likely fry your plants unless they are mutants lol.. hope this helps you a little, there is a lot of misguided information on lucas formula. It was originally intended as an easy way to grow hydroponic assuming you have near 0ppm water and use limited additives. Although it will work in other applications, there are better ways. I'm a little biased though, i've tried growing with dwc,rdwc, ebb and flow, hempy, soil with chem, organic soil. So far, organic soil beats all i've done as far as overall potentcy, taste, and smell, not to mention it's the easiest. I will always be growing all organic in soil from now on!
 

anomolies

Well-Known Member
thanks.. would like more opinions.

With the LF, what exactly is the NPK ratio you're giving the plants? Maybe i'll just look for a one part nutrient that is similar.
 
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