Growing In PERLITE/VERMICULITE

Hipster2U

Well-Known Member
Back in the 80's when I was young and ignorant I grew bag seed in solo cups using a 50/50 mix of perlite/vermiculite on a drain table, recurculating miracle grow at one tablespoon per gallon. I knew nothing about pH or anything. I ran the same solution for weeks at a time. What an idiot! I tell you, though, it was some of the most incredible weed I ever grew in my life.
 

SomethingToDo

Active Member
Around the 22 min mark, Bruce Bugbee explains what his university uses to grow.
It’s 50% Peat / 50% vermiculite.
He explains that vermiculite is the only component that contains silica which is beneficial for trichomes. Silica can be added later but it already exists in the vermiculite.
Perlite works well too but after 30 years of research, vermiculite is the university’s preferred media.
Dr. Bugbee explains in good detail a lot of different media that’s commonly used.
Check out the whole video if you have time. It’s a great resource.

I ended up watching this video, lots of great information but I believe they use the peat/vermiculite as an additive to soil. The point of the perlite/vermiculite mix is it is a neutral pH and is soilless basically. No microbes, or bacteria, and you can simply run your nutes through it and you'll have a much lower pH. Since peat moss has a pH of like 4 I am not sure how that would work without soil as a buffer. Mr. Bugbee also explains they use lime along with it to raise the pH of the peat moss.
 

ScienceGrow

Member
I ended up watching this video, lots of great information but I believe they use the peat/vermiculite as an additive to soil. The point of the perlite/vermiculite mix is it is a neutral pH and is soilless basically. No microbes, or bacteria, and you can simply run your nutes through it and you'll have a much lower pH. Since peat moss has a pH of like 4 I am not sure how that would work without soil as a buffer. Mr. Bugbee also explains they use lime along with it to raise the pH of the peat moss.
He does not use the mix as an additive to soil. His method is literally 50% peat and 50% vermiculite. He said you can use perlite in place of vermiculite, and I have used some perlite to help with my drainage in bigger pots (getting up above 5 gallons), but the vermiculite is necessary in my opinion, otherwise you would need to add silica some how.

The ph is buffered using dolomite lime as an additive, but just enough. It also brings other nutrients.

Gypsum is added to bring some more nutrients, but even less than the dolomite.

The substrate is put in a pot with excellent drainage. I am going to try putting some clay balls at the bottom of my pots this time to prevent back soaking of draining fluid, and also help with drainage.

The pots are placed in containers during watering.

***MOST IMPORTANT PART***

The cannabis pots are watered using a 20-10-20 fertilizer solution with micro-nutrients, at a EC (electrical conductivity) value of 1.3 mS/cm. They are watered until 10% of the solution is drained through into a SECOND CONTAINER, which is the fluid you collect to measure the EC. The micro-nutrient profile is similar to the ones used for orchids, but is exactly the kind used in Jacks peat-lite special or Peters professional peat-lite special 20-10-20. They are urea free. THEY ARE ACIDIC, WHICH IS WHY IT IS ESPECIALLY IMPORTANT TO BUFFER YOUR SOIL WITH DOLOMITE LIME TO COMBAT THE PEATMOSS AND FERTILIZER ACIDITY. WHEN THESE ELEMENTS ARE COMBINED I HARVESTED 2 POUNDS FROM 2 PLANTS THAT GREW FROM SEED IN 3 MONTHS. THE PLANTS GREW SO FAST THAT I HAD TO PUT LITTLE STAKES IN THE SUBSTRATE BED TO KEEP THE LOWER BRANCHES FROM BUCKLING DURING FLOWER. I ALSO HAD 2 WEEKS OF NO SUN DURING A FOREST FIRE. THIS METHOD IS GOD TIER.
 

BonnMac

Active Member
He does not use the mix as an additive to soil. His method is literally 50% peat and 50% vermiculite. He said you can use perlite in place of vermiculite, and I have used some perlite to help with my drainage in bigger pots (getting up above 5 gallons), but the vermiculite is necessary in my opinion, otherwise you would need to add silica some how.

The ph is buffered using dolomite lime as an additive, but just enough. It also brings other nutrients.

Gypsum is added to bring some more nutrients, but even less than the dolomite.

The substrate is put in a pot with excellent drainage. I am going to try putting some clay balls at the bottom of my pots this time to prevent back soaking of draining fluid, and also help with drainage.

The pots are placed in containers during watering.

***MOST IMPORTANT PART***

The cannabis pots are watered using a 20-10-20 fertilizer solution with micro-nutrients, at a EC (electrical conductivity) value of 1.3 mS/cm. They are watered until 10% of the solution is drained through into a SECOND CONTAINER, which is the fluid you collect to measure the EC. The micro-nutrient profile is similar to the ones used for orchids, but is exactly the kind used in Jacks peat-lite special or Peters professional peat-lite special 20-10-20. They are urea free. THEY ARE ACIDIC, WHICH IS WHY IT IS ESPECIALLY IMPORTANT TO BUFFER YOUR SOIL WITH DOLOMITE LIME TO COMBAT THE PEATMOSS AND FERTILIZER ACIDITY. WHEN THESE ELEMENTS ARE COMBINED I HARVESTED 2 POUNDS FROM 2 PLANTS THAT GREW FROM SEED IN 3 MONTHS. THE PLANTS GREW SO FAST THAT I HAD TO PUT LITTLE STAKES IN THE SUBSTRATE BED TO KEEP THE LOWER BRANCHES FROM BUCKLING DURING FLOWER. I ALSO HAD 2 WEEKS OF NO SUN DURING A FOREST FIRE. THIS METHOD IS GOD TIER.
I'm starting my first grow using Bugbee's recommended media and amendments.
Very happy with the results.
 

ISK

Well-Known Member
I've used both 100% perlite and 75/25% perlite/vermiculite and have not seen any noticable differences.

I now just use 100% perlite, but recently heard that vermiculite has silicon which has some benefits, so I may consider adding 25% vermiculite again
 

sadboy92

Well-Known Member
Around the 22 min mark, Bruce Bugbee explains what his university uses to grow.
It’s 50% Peat / 50% vermiculite.
He explains that vermiculite is the only component that contains silica which is beneficial for trichomes. Silica can be added later but it already exists in the vermiculite.
Perlite works well too but after 30 years of research, vermiculite is the university’s preferred media.
Dr. Bugbee explains in good detail a lot of different media that’s commonly used.
Check out the whole video if you have time. It’s a great resource.

a bit late but want to add a couple comments:
1. Bruce Bugbee is the man. Not only is he super knowledgeable, he has a very friendly vibe to him. Super soothing and educational videos.
2. Although I've never tried vermiculite (and I know many have had poor experiences with it), I *do* know that peat is incredibly hydrophobic. When peat completely dries out, getting it wet is a b!tch. I surmise that mixing peat with a hydrophilic medium like vermiculite might keep the peat consistently damp-but-not-wet with the right pot system and watering schedule.
(3. I don't know off the top of my head what potting system and watering schedule Bruce Bugbee uses.)
 

SomethingToDo

Active Member
He does not use the mix as an additive to soil. His method is literally 50% peat and 50% vermiculite. He said you can use perlite in place of vermiculite, and I have used some perlite to help with my drainage in bigger pots (getting up above 5 gallons), but the vermiculite is necessary in my opinion, otherwise you would need to add silica some how.

The ph is buffered using dolomite lime as an additive, but just enough. It also brings other nutrients.

Gypsum is added to bring some more nutrients, but even less than the dolomite.

The substrate is put in a pot with excellent drainage. I am going to try putting some clay balls at the bottom of my pots this time to prevent back soaking of draining fluid, and also help with drainage.

The pots are placed in containers during watering.

***MOST IMPORTANT PART***

The cannabis pots are watered using a 20-10-20 fertilizer solution with micro-nutrients, at a EC (electrical conductivity) value of 1.3 mS/cm. They are watered until 10% of the solution is drained through into a SECOND CONTAINER, which is the fluid you collect to measure the EC. The micro-nutrient profile is similar to the ones used for orchids, but is exactly the kind used in Jacks peat-lite special or Peters professional peat-lite special 20-10-20. They are urea free. THEY ARE ACIDIC, WHICH IS WHY IT IS ESPECIALLY IMPORTANT TO BUFFER YOUR SOIL WITH DOLOMITE LIME TO COMBAT THE PEATMOSS AND FERTILIZER ACIDITY. WHEN THESE ELEMENTS ARE COMBINED I HARVESTED 2 POUNDS FROM 2 PLANTS THAT GREW FROM SEED IN 3 MONTHS. THE PLANTS GREW SO FAST THAT I HAD TO PUT LITTLE STAKES IN THE SUBSTRATE BED TO KEEP THE LOWER BRANCHES FROM BUCKLING DURING FLOWER. I ALSO HAD 2 WEEKS OF NO SUN DURING A FOREST FIRE. THIS METHOD IS GOD TIER.
I guess I got confused because he started talking about soil oxygen levels and I figured he was referring to his mixture of gypsum/coir/peat/vermiculite as soil.
 

SomethingToDo

Active Member
I've used both 100% perlite and 75/25% perlite/vermiculite and have not seen any noticable differences.

I now just use 100% perlite, but recently heard that vermiculite has silicon which has some benefits, so I may consider adding 25% vermiculite again
I was running 100% perlite but I was hand watering which caused some issues. Once the plants got rather large I was having to hand water them constantly. If I setup some kind of automated watering system this wouldn't have been an issue but I didn't want to hassle with setting up a reservoir. So for me adding 25% vermiculite to the perlite really helps with water retention and delays how many waterings I have to do in a day.
 
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downhill21

Well-Known Member
I ended up watching this video, lots of great information but I believe they use the peat/vermiculite as an additive to soil. The point of the perlite/vermiculite mix is it is a neutral pH and is soilless basically. No microbes, or bacteria, and you can simply run your nutes through it and you'll have a much lower pH. Since peat moss has a pH of like 4 I am not sure how that would work without soil as a buffer. Mr. Bugbee also explains they use lime along with it to raise the pH of the peat moss.
Negative. The peat / vermic is the medium.
 
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