Need soil mix help

h.h. said:

Are you in buckets?

Click to expand...

Microbeman said:

Is that one of those pH probes that you poke in the soil or did you check pH correctly?

Click to expand...

DTOM420 said:

It is a probe that you stick into the soil. Yes, I know that most of them are very inaccurate; but this one was recommended by several good growers I've met and it has matched all the slurry tests (is this the "correct" way you're referring to?) I've done. I have not done a slurry test lately because of this past reliability. But, I certainly can. Is there some other method, aside from the lab test, that I can use?

EDIT: I'm doing a slurry test right now. I'll post results in a few, when it's finished.

Click to expand...

Microbeman said:

If it is a meter which can be calibrated there is a possibility of accuracy, otherwise I've never heard of a soil probe under 500 bucks that is worth having. I could be wrong though. I've had several cheap ones and none were accurate.
Yes I mix substrate with distilled water to test pH. Some use run off water.

Click to expand...

DTOM420 said:

Thanks Tim! I couldn't get my Apera PH20 pH meter or even my pH test drops because they're in the grow room and the lights went out before I could get them. It'll have to wait until tomorrow.

It's entirely possible that I have misplaced my faith in this soil probe. Your knowledge is more than anyone I know but there are some really successful folks that run the plant infirmary on another community I belong to and they swear by that one particular tester as a good tool - Not anywhere near as good as those $500 units, but still helpful. They say all the other probes are a waste of money as well. The accurate 8 runs $60-$70.

Regardless, can you tell me your recommendation on how to add lime to a mix where you wanted to raise the soil pH? I mean, would you add it until you reached your desired pH and run with it OR would you add some, let it sit for a while, test and add more and let it sit again, etc until you finally reached the proper pH? Just no sure if the cooking/curing is required or if you can simply adjust all at once and run immediately? I'd like to know for future reference and my own knowledge.

Click to expand...

Microbeman said:

To start, meters which can be calibrated are normally placed into at least 2 different solutions (#4 and #7 approx.) to calibrate. Is this the case?
Temperature and moisture levels can cause different readings. I use auto temperature and altitude compensation meters.
Did KIS recommend the "Recharge, Great White Micorrhizae and a soil bacteria and probiotic called BiotaMax" and the bat guano?
Personally, I would use equal parts peatmoss and compost. Organic matter is the number one pH stabilizer, in my opinion.
There are several things that could be playing with your pH. The compost used could still be degrading, the sulfur in gypsum, the bat guano, anaerobic activity. Is the oyster shell flour the commercial mined product or crushed oyster shell? I use grit myself.
You could use a small amount of dolomite or limestone but like many organic growers I personally ignored pH once my plants were in. I used the meters for interest and research.
I figure, the mix you have is meant to support one growth cycle. It is much more complicated than I would use but it is what you have.
I suggest giving it more time. Basically you have created a compost heap that needs to finish.

It seems that things have changed since my conversations with Coot where we talked about mixing several ingredients and plant immediately. Soil cannot be living without a plant.

Click to expand...

DTOM420 said:

I mixed up a batch of soil and it's been curing/cooking for 48 days. I'll post the complete recipe below but its a Coots Mix base that I included all the additional amendments found in KIS Organics' complete soil mix; and Tad even gave me recommendations on the amount of each amendment to add. The last time I checked (2-3 weeks ago) the pH was right at 6.5, according to my Accurate 8 Soil pH Probe. However, when I checked it today, one container was showing 4.6 and the other one was showing 5.2! Now, I did add some biochar that I had crushed into small pieces and charged with some biology using Recharge, Great White Micorrhizae and a soil bacteria and probiotic called BiotaMax. I added those inoculants to some pH'd (6.5) water and made a slurry with the biochar that soaked for several days before I added it. I also watered the soil once with slightly alkaline water (pH 7.8) with some unsulphured molasses, thinking that it'd feed the microbes in the soil. I'm not sure whether one of these two things caused the pH of the soil to drop so much but I know I need to do something......just need some help with what that something is?

Question 1: Should I just add some AG lime to raise the soil pH? This seems like the simple solution but I don't know if it's the best answer. Also....How should I apply it? Should I add a cup to 10-ish gallons and then test the pH and keep doing this until I hit 6.5? Or, should I add a cup and let it sit for a bit again before testing it and then add more?

Question 2: Is there something else I should be doing to raise the pH

Question 3: What could cause this drastic pH drop?


Here's the ingredient list:

3.75 Gallons Lambert Sphagnum Peat Moss
1.25 Gallons of Compost and EWC
2.50 Gallons of Pumice
4 Cups Basalt
4 Cups Glacial Rock Dust
4 Cups Gypsum
4 Cups Oyster Shell Flour
3 Cups Malted Barley meal
2 Cups inoculated BioChar

1 Cup Insect Frass
1/2 Cup Kelp Meal
1/2 Cup Neem/Karanja meal mixed 50/50
1/2 Cup Crustacean meal
1/2 Cup Alfalfa meal
1/2 Cup Feather Meal
1/4 Cup Fish Bone Meal
1/4 Cup Rock Phosphate
1/4 Cup N Bat Guano
1/4 Cup P Bat Guano

I know that getting a full blown soil test from Logan Labs would be the BEST thing I can do but I can't afford it right now. So, I'm looking for the next best thing - some ICMag advice!

Click to expand...

I’m confused about your assumption that this was for a single grow cycle because it had so much in it? I was actually hoping for a soil that I could reuse over and over with less reamendments (if any) needed between cycles. With all that in there I figured the microbes would have plenty to break down for many cycles. What makes a simpler mix more conducive to a multiple run soil or living soil or whatever the term? I’m missing something. Sorry if I’m being dense but sometimes I’m slow to catch on. Lol!

Click to expand...

KIS said:

Hey wanted to chime in here with some thoughts too:

1. I think you would be better off doubling the base mix like you suggested, that's a lot of nutrients.

2. I think your pH meter is probably off, I wouldn't place much value in the reading. From looking at your recipe I would think if anything you will be alkaline or soon be alkaline from all the Ca you've added.

3. Better to err on the side of not enough nutrients than too much, so you can always add fertilizer/nutrients during the grow cycle.

4. A soil test, even the $25 one from Logan would give you a better idea on pH and your macro nutrients. My hunch is you're pretty high on P and Ca based on the inputs and possibly N, though that's less of an issue.

5. You can always throw a different less valuable plant in the mix and see how it does from a testing perspective.

Hope that helps! Oh and yes we do use a diversity of inputs in our mix, but I cannot say that there's been any research to show that delivers a better plant outcome. Anecdotally I like diversity for the potential to add/feed a greater diversity of microorganisms, but I wouldn't get hung up on your number of inputs but rather the quality of them, especially the worm castings/compost fraction. I'm confident you could grow excellent plant with a very limited number of inputs too.

Click to expand...

Microbeman said:

I meant just with those nutrients and water would see you through a single cycle, not that you could not keep growing in the same soil with additional amendments.

Click to expand...