Hi, This is my first post and my first time trying to grow cannabis.
Bruce bugbee seemed scientific, decided to try his mix but after mixing 50/50 peat and vermiculite +lime and gypsum my pH is around 7.0.
It was the time I figured out almost all the peat moss here are around 5.5 to 6.0 in pH.
what is the best way to fix this if i couldn’t find peat with more acidity?
thanks a lot for taking your time
5 Likes
Welcome to OG!
4 Likes
Welcome to Overgrow!
Have you watered it in well and done multiple slurry tests? It will read different depending on your waters input pH.
Come to think of it, lime is likely the buffer that’s keeping you up. Possibility? 
5 Likes
Use less gypsum and lime. You could dilute your current mix with a bit more peat and vermiculite to lower the pH.
It may go down after watering a few times and given some time to “cook” (week or 2).
6 Likes
Tnx
I did multiple slurry tests with different soil to water ratios from 1:1 to 1:2. I rinsed the mixture and it only helped a little with my reverse osmos water at around pH 6.5. added a more peat but still way far from 5.5 as mentioned in the videos I watched.
I dont know much about these materials, pretty new to botany in general. but as the videos describe lime is supposed to raise the pH which i didn’t need in the first place and this dolimitic type will add nutrients like Ca if i recall correctly
2 Likes
Thank you for the reply.
unfortunately I made the mixture before testing raw ingredient’s pH. there was some peat left and I added them but will never get to 5.5 with peat at 6.0.
what is the highest pH I can still grow safely?
will the plant lower the pH?
is it recommended to wash the mixture with adilute acid or add something like sulfur?
3 Likes
Welcome to OG, @Sohrab! It appears that you are well on your way to being an official weed grower! 
It’s a good club to be a member of. 
3 Likes
You want your pH at 6.5 according to bruce bugbee.
1 Like
Hey @ThePotanist . I have not seen you for awhile. Can you help this fellow with his PH problem?
1 Like
Thanks for tagging me @Magu ! I’ve been lurking as I can but its summer and I’ve been working to get my research plots up and running.
This is a great question about pH. The reason pH is recommended to be between 5.5-6.5 (soil you can go a bit higher and my experience has been 6-6.8 is a fine pH in soil) is because nutrient availability changes with pH. Too low or too high and you start to tie up nutrients in chemical forms the plant cant access very well. Or the nutrients are outcompeted for root space. Either way, not great. Also, a lot of harmful elements (heavy metals) become more available at high and low pH.
Peat is a common additive but im not very fond of it. Peat used in blends is a product of Peat moss and has a very acidic pH (pH 3-4) that can lock out lots of nutrients and harm plants. This is because bacteria in Peat convert sulfur to sulfuric acid. Typically, the best course of action is to try and alter the pH by soaking before mixing.
Your situation here sucks, and its not your fault. You paid good money to buy bagged soil mix from a name you can trust and it boned you. Honestly, I would trash my current grow and remix my soil. Adding some calcium carbonate (calcitic lime) will help and so will adding wood ash. Like literally burn a bunch of wood and add the ashes (good source of potassium also!). Biochar is another option to mix in, it is super good for soils and will help raise the pH while also help to retain nutrients and regulate water content. Plus its a cool substrate for carbon capture and promoting microbial growth!
It will take a little work to get your soil in good condition, through no fault of your own. But it is absolutely possible to do!! Feel free to reach out if you have any more questions, love helping people just getting started!
9 Likes
Let me ask if you have planted any seeds yet? If you have germinated seeds just gently wash off the roots and transplant into potting soil. If you have not germinated seeds then you can experiment with different things until you get it the way you want it. I never throw anything out. I either fix it or kill it with kindness but I keep trying. That is how we learn. When I grow a new exotic plant I will likely kill several before I learn how to do it. This community will help you every step of the way. 
2 Likes
Thank you very much.
I’m astonished by generosity of members here and amount of contribution on this basic topic in this short period.
I actually germinated two seeds seemed to be same strain from the same pack that I collected from weed packs over the years. the other shortage where I live is unavailability of legit seeds due to it being illegal. One could probably find original seeds here but i guess it’ll take some time and money to do so because of all the fakes that we’ve heard of. surprisingly they did a very good start and came out of soil in less than 5 days.
In the meanwhile I started making a growth chamber to be able to control the odor in the upcoming stages. first i tried with a low power light till the lights arrive and it slowed the growth as expected. after receiving lights and media I upgraded the lights and did the mix and transfer late at night. it was in the morning that I figured out the ventilation is not adequate for the high power lights and temperature has reached to 35°C and after testing the mix pH it was approaching to 8. it was too late both seedlings sadly died. I’m not sure which parameter was more lethal, heat or nutrient imbalance. they survived about two days in the new mix
1 Like
Thanks for the detailed explanation
I will do some more research on the additives you mentioned, prefer it to be fixed by some additives rather than buying more peat and vermiculite which i don’t need at the time.
But here most of the peat on the market with different origins have pH level in range of 5 to 7
1 Like
Tnx. referring to his video from 4 years ago titled: Maximizing Cannabis Yields with Dr Bruce Bugbee
he start with peat at 3.8 and by adding vermiculite it will be 4.5, dolomitic lime 40g/ft3 will bring to 5.5 as he describe as near optimum. I watched many videos from him even briefly talking about his new mix and in one maybe mentioned that they run the plants at higher than 5.5. do you have any links to a better video? I read on Reddit about a video dated about one year ago but couldn’t find it.
1 Like
Id recommend going with a bag of Mother Earth or Fox Farms soil. Its easy to start and you can amend with stuff like bone meal, blood meal, slow release granular nutrients, etc to recharge. If you can use a compost tea to charge the microbes up you won’t have to worry as much about pH. If you use the soil long enough and rotate different plants when growing Cannabis you can even make disease suppressing soil which is super cool!!
Even with adjusted Peat soil id be worried as the Peat breaks down. Peat, by definition, is extremely acidic and even if treated the breakdown products may be highly acidic. It is also a non-renewable and non-sustainable resource that does more for carbon capture in its own environment than it does as soil component in my opinion.
Bugbee’s recipe is only going to work if you use his same ingredients. And my guess is he has a conditioning period where he keeps plants out of the soil as it becomes more amenable to supporting growth. I also would shoot for the 6-7ish pH range as it seems to be more favorable for soil. If you use Peat as a soiless media then 5.5 is a good number, but really you got a range. I dont have it saved on my phone, but you can find charts that show nutrient availability based on pH on Google that will help illustrate the importance.
3 Likes
2 Likes
after leaving the mix wet for couple of days it’s pH is decreasing and it’s around 6 now. It seems that microorganisms are changing the environment right?
It seems the problem is going away and I can start using the mix.
Thanks for all the participation
3 Likes
Welcome to the OG ! 
1 Like
This happens with other blends also! Sometimes you just gotta let it condition a bit. Patience is a virtue in both plant growing and soil making apparently!
Happy to hear things are working out! Make sure to post pics so we can all enjoy and appreciate your work!
2 Likes
Or possibly there’s a buffering agent (eg lime) that is adjusting the PH.
Cheers
G
3 Likes