Run off ppms for soil

I’m curious what’s a good run off ppm/ec for soil using synthetic nutrients like GH, FF , Ect. Also what do should the ppms get down to before feeding again? Thanks for any info.

I maintain my runoff PPM at 1,000 throughout the grow. Levels lower for a young plant is a good idea.


Got a question for ya. I’m having a problem with some plants turning light green up top. Ive used 3 different nutrients. I am adding lime but my ph is always between 6.2 and 6.7. Some of my plants will stay dark green and healthy with the same feed. Shit is blowing me away. It looks backwards of a nitrogen defiency.

The leaves are turning purple i guess where the chlorophyll is leaving the plant.

Also when im adding additives , should i still aim for 1,000 ppm ? Or do the base nutes up close to 1,000 that then add the rest like it says?

Lime isn’t a quick fix that will lower pH in a reasonable timeframe. It is helpful for balancing pH, but it cannot be used as a pH down product. Lime needs time to break down to have an appreciable effect.

Are you citing the runoff pH?

Some plants seem to be stubborn.

Maintain a runoff PPM of ~1,000 regardless of the additives used (silica, etc,…)

The desired ph for soil is 6.5 - 6.8.

New growth is usually a lighter color. That is not unusual or of concern.

The pale lower leaves look more like a magnesium deficiency. Are you adding CalMag? Lime should be adding Ca & Mg but it takes time for it to become available to the plant.


If your runoff pH is between 6.2-.8 you’re golden. I highly suggest sticking to one nutrient line. Most liquid, multi-part nute systems also need calmag incorporated.

Also, depending on your water source, shoot for 1,000ppms in/out as @MidwestGuy suggested. If you use tap or well water, take into account these can have already higher ppm’s, before mixing, whereas RO or distilled is virtually 0.


What nutrient line is best for soil you think. Im having problems with fox farm around week 4 of flower, its very aggervating. Mostly what you see here and yellowing leaves.


I use Jacks 321 for soil or coco. Its part A and B, with epsom salt (magnesium sulfate) Standard jacks ratios per gallon are…

3.6g part A
2.4g part B (calcium nitrate)
1.2 epsom

Mix part A until dissolved, then epsom until dissolved, and lastly part B.

I use tap water for soil. At that ratio, my pH falls to 6.43 every time. There are slight variations that other growers use, but that is standard, unless Jack’s has changed it. I use 4g part A, and 2g part B, no epsom, without issue.