Grat3fulh3ad's Modified Lucas Formula

[hippie420]

So I will start by saying this is not my work or information by any means... This a popular Modified version of the Lucas Formula made by an icmag.com member named Grat3fulh3ad.

Highyas guys...

After watching and reading and generally being impressed with the results you've all been getting with the coco medium, I've had to make the switch myself...

Being the rebel that I am...Not having coco specific nutes, and having a full supply of GH flora micro and bloom, I've been working at tailoring the 'Modified Lucas formula' I was using in pro-mix to suit the coco better...

The mix I have arrived at has reduced levels of K and P, and a slight reduction in total concentration, because I have been keeping the runoff to a minimum (only a few ounces of water come thru, just enough to let me know I'm completely saturated...

So... when I was using a modified lucas formula... my nutrient profile when growing in promix was:
N 130
P 93
K 163
Mg 64
S 43
Ca 130

By mixing 8ml/gal micro and 14ml/gal bloom and watering with plain water every other watering...

In the coco, I am now using 6ml/gal micro and 9ml/gal bloom which gives the nute profile:
N 97
P 60
K 105
Mg 27
S 41
Ca 97

adding 1 g/gal epsom salts to the solution changes the numbers for mg and s to:
Mg 67
S 61


Adjusting for the extra available potassium in the coco, the new formula puts me very close to the 'target ratio'... Phosphorous is a tad low, but I think there should be no worries there...

Nothing is too far along in flower right now, but I'll get some pics up a bit later.

I have also seen advantage in keeping the coco fairly wet, I'm guessing that the coco holds the nutes so well, that as moisture evaporates out, concentrations rise...

Hope this helps some folks
-Hippie-

[Piggie]

Do you "charge" the coco with cal/mag or something similar before starting?

[hippie420]

No I just read through the post I got this info from and he's states that Cal/Mag would cause him issues in his formulation.