Asked by humbleumbelfarm ·January 19, 2022 ·6.91k readers

Minerals (Diluted Seawater) Ratios and Soil Formula Application

Hi Drake, wondering if you could clarify diluted seawater ratios. At different places in your Pure KNF Recipe Book you have both 1:20 and 1:30 ratios listed for the soil formula/drench. And it looks like you're using 1:25 in the recipe on your soil treatment slideshow pdf. Does it matter which of these ratios I use for soil treatment? And I suppose it's better to use the different Minerals ratios listed in your book for different growth formulas, e.g. soil, bloom, fruit, rather than using one general ratio for all formulas? And for application of the soil formula, I plan to fertigate 3000 ft2 at a time which at 5 gal/100ft2 would be a 150 gal soil formula recipe. Can I put all the ingredients for this 150 gal recipe in a 5 gal bucket of water and fertigate it? Or do I need a larger tank? My fertilizer injector does 0.5-2.0%, which prob doesn't matter, but essentially it would be way over diluted by the time I run it through drip tape for 1 to 2 hrs and put out over 700 gal per hour on that 3000 ft2. Suppose I could run it for a shorter time to approximate 150 gal but it might not soak in much. Trying to find an approach that works for an acre of veggies. I have a 55 gal sprayer but fertigating is easier whenever I can do that. Super inspired by your work! Thanks for sharing bro! Cheers - Brian - Humble Umbel Farm

minerals soil-formula soil-drench

Top answer

dagoofman · Jan 23, 2022

iv been fertigating through a hose end sprayer for a yr now and it works great u just have to get the solutions correct for your sprayer the one i use has a dial so i adjust the sprayer to the solution i feel that even with overspray im just feeding the soil microbes and the plant so it cant hurt id guess and KNF is cheep enough that spraying extra outdoors through fertigation is not a big deal the only draw back is that unless u r mono cropping u r losing some of the nuance of KNF so i really only tend to fertigate 2-3 solutions on the regular leaf & growth (fat) and root & structure (skinny) i also do soil prep solution through the fertigation those i feel r more of a overall that every plant needs then i go to a pump sprayer during fruiting and ripening to tend to what each plant needs in that cycle of life if u r doing more of a mono crop in your fields id think fertigation would work really well i got the idea from a Drake KNF vid dont remember which vid it was they where making solutions and someone mentioned that one of the guys there uses fertigation for there solutions and they had just done the math to get the ratios right and its worked well for me happy experimenting

From the KNF library

From the KNF library Drafted by Claude from Office Hours and the books · Sep 2026 · 7 sources

Drake's library gives 1:30 as the standard soil ratio for diluted seawater. (Cho's Solutions, p. 15) The manual's 30 gallon recipe is 1 gallon of seawater in 30 gallons of water. (Pure KNF Manual, p. 53) Scaled to 150 gallons, that is 5 gallons of seawater. (Pure KNF Manual, p. 53)

The recipe book lists more than one ratio. It gives 1/30 as the dilution, then 1/30, 1/25 and 1/20 for ripening. (Cho, Recipe, p. 82) So 1:25 and 1:20 both sit in the book. Drake once said the book's ratios confused him. (Office Hours Ep. 148, 1:04:03)

The ratio does change with the job. The harvest formula uses seawater minerals at 1:10 to 1:20. (Office Hours Ep. 17, 54:08)

On tank size, Drake drenches his worst field through a 250-gallon tote. (Office Hours Ep. 30, 47:45) He also dumps about 10 gallons of seawater into a 275-gallon tank. (Office Hours Ep. 159, 26:06)

The library does not cover mixing 150 gallons in a 5 gallon bucket, injector settings, or drip tape run times.

Sources