Lab Test Results From My Soil

Haven’t had anything interesting to post in a while. I decided to spend $40 and get my soil tested by a laboratory. This soil is what is left from my last indoor grow, all I did was chop the stem at ground level. My last grow was probably the worst one I have ever done, very poor yield and quality.

I will need to take some time to digest these results and try to understand them. Anyone have any thoughts right off?


Your numbers are crazy high. More like toxic. They’re telling you to add more N to help compost the excess of other minerals. I’d dump that into a compost pile and start again with new soil.


I apologize, I should have gave more info about this soil instead of just posting the lab results. It was late and I was sorta tired out.

So, this is the living soil from my last grow. Here is the original mix:

During the entire grow it was water only with the exception of a top dress with some Langbeinite 0-0-22 one week into flower and then a few feeds of organic Potassium. The plants looked like they had a Potassium deficiency which never improved after the feeds.

This is the fourth time using this basic recipe, the first three grows did fine this last grow was less than stellar. I had a lot of things going on in my life at the time; work, taking care of my disabled wife, had a heart attack (damn!) so my plants got ignored more than they should have and might not have been because of the soil mix.


Holy smokes those are some toxic levels Did you amend the FFOF with these nutrients then start the grow? That medium alone and straight from the bag is around 2500-3000 PPMs. Most organic growers don’t start top dressing nutrients for several weeks using these types of medium :love_you_gesture:


Actually I did amend the FFOF at the start of the grow. I followed what some other folks did with this who achieved great results. But you know how that goes.

It was hot for sure, I saw signs of excess nitrogen during the grow. The thinking is it takes ‘some’ amount of time for all this to break down and become usable. How much time I can’t really say.

I would like to add a couple of things. The soil test is geared towards agricultural testing with ‘high’ being optimum levels on this chart. I don’t know how applicable the relative ratings are applied to this type of highly amended soil.

I did test the PPM of my sample before sending it in and got a reading of just shy of 4000 ppm.


It is interesting to see the distribution of NPK and other nutrients in a PPM that is so high.

Cool test. Thanks for sharing.


It was locked out.

This may put your test into perspective some more.


Exactly. Too much calcium probably caused the potassium lockout? This soil test has been very informative so far.

Unfortunately they didn’t perform a cation exchange capacity (CEC) test so I can’t convert my PPM’s to base saturation levels. Unless there is some math I am not seeing right off.

I haven’t found a similar chart like you provided that shows relative PPM’s. Do you know of any?


I had the Lab send me the relative ppm’s they use for their charts based on a typical flower garden. On this spreadsheet below I scaled my ppm’s down by a factor of 10 to see the how the ‘balance’ between the minerals are.

I don’t know for fact but expect most of us run much hotter than your average outside flower garden so I don’t think I am 10x too much. If anyone can shed some light on that it could be helpful to me.

I was going through some posts from VIVOSUN facebook a bit last week and someone posted about miracle grow and cannabis, which is a weed. They also had problems, low yields an various problems. After reading made sense. Miracle Gro gets rid of weeds. Right after reading I went with fox farms

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Hi All,

Just thought I would update you on what I did this extremely hot soil. I ended up mixing it with peatmoss at a rate of 1/3 parts soil to 2/3 parts peatmoss.

I just flipped to flower mode a few days ago and so far my three plants (different strains) look really nice.

I got a crap load of peatmoss left over and would like to try and use it to build some more soil for my next grow if possible… if not I gets dumped outside somewhere.


Coming up on the end of the stretch, all three plants look fabulous… not a single brown/yellow spot anywhere. I had them in 1 gallon containers in this hot soil (before diluting with the peatmoss) and they were struggling with it.

Normally I finish them out each in a 3 gallon container. This time I planted the three of them in a single 20 gallon container. Maybe it is because my last couple of grows have been less than stellar… embarrassing to be honest. But I couldn’t be happier with how this grow is doing.