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View Full Version : What should be a maximum ppm?



senorx12562
10-27-2009, 08:09 PM
Growing in soil, White Rhino, 3weeks into veg, using organic food (Age old grow), what would be a safe maximum post-feeding nute level in ppm (measured at runoff water)? Any help would be appreciated.

DreadedHermie
10-27-2009, 08:49 PM
I don't have a clue!

(For one thing, it will depend on ppm in your water...)

You could increase the dose very gradually, then back it off when tip burn starts to show.

a) I would do this on a test plant or 2, not the whole crop

b) Personally, I prefer a more conservative feeding plan. Less problems with buildup in the soil, better taste, etc.

I've found that running hot nutes in soil requires a close eye on soil moisture. As the soil dries out, the unused nutes become much more concentrated.

A safe nute level with moist soil can burn as your soil dries out. Just my experience, YMMV. Hermie :thumbsup:

senorx12562
10-28-2009, 12:38 AM
I don't have a clue!

(For one thing, it will depend on ppm in your water...)

You could increase the dose very gradually, then back it off when tip burn starts to show.

a) I would do this on a test plant or 2, not the whole crop

b) Personally, I prefer a more conservative feeding plan. Less problems with buildup in the soil, better taste, etc.

I've found that running hot nutes in soil requires a close eye on soil moisture. As the soil dries out, the unused nutes become much more concentrated.

A safe nute level with moist soil can burn as your soil dries out. Just my experience, YMMV. Hermie :thumbsup:
My tap water starts around 200 ppm. If you see my posts re horticultural oil in this forum you'll see why I'm asking. Essentially, I od'd my plants on nitrogen by using a fish oil based product to kill spider mites, not realizing that fish emulsion is used as a fast acting cure for nitro deficiency, and I had just fertilized the day before. Voila, a ppm reading in my runoff of over 2000ppm. I spent 6 hours today flushing all of my plants, and was wondering when to stop. No one responded, so I got most down to below 1000 ppm. I actually flushed them so much I had to add soil to cover up the grodan cubes.