Root health and Drainage

Hello everyone,

Super noob here. I’m stopping by to impart my ONLY nugget of wisdom on cannabis growing. I’m new to this hobby and I will be the first to admit I know less than most. BUT I do have a tip that might help others and even enhance the experienced growers. Oh, and it saves money too.

The first lesson I learned was that cannabis LOVES airy soil. 

Loves Loves Loves it.

  Most people turn to Perlite to bolster the oxygen in their soil, keep it light and porous for easy drainage. However, perlite doesn't come cheap and you can't reuse it. It breaks down and turns into dust after a few grows. I thought about what I could do to fight the root rot and overwatering problem we all encounter as beginners. Drainage is a serious issue to some and I think I have a clever solution. 

I started using perlite and realized that if the silt from the soil collects at the bottom of my fabric pots I'll have a issue with drainage. My little brain started working and soon I shifted it into overdrive. There HAS to be a better alternative to perlite. My fingers went "tappity tap tap tap" on the interwebz, Lava Rock? Pumice? Volcanic stone? Propane BBQ briquettes? YES that MIGHT work. 

Researched a bit and to my surprise, this is the answer I’ve been searching for. The lava rock does nothing to the soil. Completely inert, neutral to the environment, cheap, reusable, in abundance in EVERY hardware store and Big Box traps I.E. Walmart, Target, HomeDepot, Lowes etc.

I bought myself a bag and began to toil. Laid down 2 inches at the bottom, filled up the rest with my soil mix. FF Ocean Forrest w/20-30% perlite. Fast forward a few months and it was working GREAT. If it works this well on the bottom, how about a smaller lava rock mixed in place of perlite? Got myself a small bag of one quarter inch to three eighths sized rocks.

I'm going to include a few photos to better explain my discovery.

This is the bottom 2 inch layer of Lava rocks for immediate drainage assistance.

Size comparison for the 1/4 - 3/8ths bag of pumice.

This is the bag and brand I purchased incase you wish to do the same or if your local store carries it.

I decided to go the Lava rock route because it’s reusable and with a garden hose and 30 minutes drying time you’re ready for the next grow cycle.
Extremely porous, lots of air pockets, nooks and crannies for nutes and Myco to flourish and one hell of an anchor for your plants roots.

This coming month I’ll be in harvest and I plan on replacing some of the perlite with the smaller lava rocks (keeping the roots clear of anything binding of course) to see if the extra surface area will yield more available oxygen to the root zone of the plant.

The best thing I’ve ever read on here was “Focus on root health and growth to get a better outcome on top”. And that is probably the best advice one can ask for as a noobie getting into this hobby.

I forgot who the author of the thread was but if you're reading this? 

THANK YOU EMENSLY for that super nugget of wisdom.

Hope everyone is having a awesome weekend.
Chin up, Monday is still 1 day away.
Kindest Regards,

Wow! Seems like a really good idea! Keep us informed on how it turns out.

It must have a PH value to it…
Clay pebbles do
I would imagine you need to soak it in ph’d water for 24 to 48hr to buff it.


I’m glad you pointed this out, because I forgot to add an important detail in my above statement.

When you initially open and dump the Lava rock, it’s dirty and dusty. So a quick rinse is definitely in order. What I chose to do was dump the pumice out into a colander and hit it with a garden hose to get rid of the dust and dirt. Once the rock is cleaned, just let it dry and splash it with pH corrected water. Again let it dry. NOW you’re ready to go.

My initial attempt had a 0.2- 0.5 swing in pH… As I’m trying to keep everything between 6.5-6.8 pH. It wasn’t much but if you’re shooting for a target you need to allow yourself a correction window. (I was able to achieve this by just dumping 7 pH water over the rocks and pulling a pH reading from the standing water, 7.23-7.5 was the average after cleaning 4 bags, one bag at a time).

Let me clarify a bit more. My tap water is pretty damn choice. (The first time I’ve EVER gotten lucky over something so trivial) I spit a constant 6.9-7.1 out the faucet each and every time I turn the tap. Unfortunately I ALSO have chlorine and fluoride in my municipal water so I need to let it sit around for a few days before I even use a drop.

So with a quick rinse and a splash of corrected water the base pH of the lava rocks are whatever your corrected water is. Once dry they are left with the pH value of your final rinse.
Easy enough right? Well it was a little bit of a nut pinch getting to this point but I ain’t got crap else to do so why the hell not, right? Hope this helps a bit.

I’m about 2 weeks from starting my next experiment. What I’m planning to do is take two identical strains, put on in a pot with soil and perlite and the other lava rock instead of perlite. I’ll water them the same, give them the same nutrition, same soil amendments, same light time and light distance, I’ll even try to LST each plant in the same manner.

Well, that’s my plan and I’m really not even going to try and predict what will happen. I’ll just have to let nature tell me if I’m doing something the plants like or not.

Hope everyone is enjoying their Sunday morning.
To those of you of faith, God bless you, to everyone else I hope you are relaxing
on this day, kicking your feet up and doing something fun or meaningful for yourself
and loved ones.
Have a great day all,