Sterilization and Re-use of Media?

[aintdedyet]

Hey y'all … haven't posted in quite a while, but aint ded yet!

Hope you're stayin' virus-free, and perfecting those social isolation and distancing skills. Never thought I'd see the day when I had to turn down sharing some smoke with anyone. Like many of my fellow forum members, I'm an old fart considered vulnerable.

So as part of doin' my part, I'm resisting the urge to visit the local shop. The problem is I'm out of media for my next indoor grow. The good news that I've stockpiled a bunch in the back yard from previous grows. It's a mix of potting soil, soil-less media (sphagnum-based), perlite, vermiculite, used both indoors and outdoors for previous cannabis grows, and for vegetables (all container grown). I spent some time sifting out the roots, and it looks like it will be a suitable media (good porosity, high levels of residual organic material, etc.).

My main concern is bringing nasty bugs and pathogens indoors, so would it be feasible to sterilize the media before use? Wish I had an industrial or lab-sized autoclave, but lacking one I'm thinking of cooking small batches either in the oven or the microwave … I'm thinking a steaming operation would be too messy in the kitchen. I need 12 gallons to fill 4 fabric pots.

I appreciate this will render the media essentially bare of any bacterial or other beneficial "living stuff", but I guess that's the goal, to eliminate any pesky critters that might come in and cause me problems later.

Any thoughts/input on this greatly appreciated ...

p.s. I'd be remiss if I didn't share what I've been up to, and some pics. Upgraded from 3 x 3 to 4 x 4 tent, and added a 600W LED to lighting. Currently entering harvest window on a set of 4 Blueberry x Lemon Haze autos that were started mid-January, topped once, LST'd, and defoliated on an ongoing basis. Pretty uneventful grow, but not happy with the particular brand of soil-less media that I used this time. Insufficient drainage, taking a week between fertigations, and ended up with WPM showing on the 5 gal. fabric pots (see pics). Ended up given H₂O₂ treatments, cutting slits in the lower part of the grow bags, and directing another fan right on the pots. Did the trick, and lucky no spread to plants. Surprising the difference in drainage characteristics between what you would think are just variations on the spaghnum/perlite theme.

Oh yeah, these autos caught me off-guard a wee bit by starting to flower in only 3 weeks, soon after topping. May have lost some yield, but it is what it is.

Previous grow was 4 WW autos, averaging approximately 3 oz. per plant, harvested indoors late November. Ran into a CalMag deficiency, but survived. Have since researched municipal water quality report and noted only 30 ppm of hardness. No wonder the deficiency, and have since incorporated CalMag into regular fertigation. Funny how you never stop learning … eh?

Before that was the summer grow. A wee bit of a nightmare, but it worked out OK I guess. 770 g from two Blue Dream and one Super Silver Haze, about equally divided between decent smokable and chocolate chip cookie material. Basically ran outta summer time. Mucho problems with bugs, some bud rot, immature bud development, and the dreaded hermies. In the end we ended up loading them onto my grandson's wagon and muling them into the garage, just to try and salvage a few more days. In the middle of a fairly good breeze too of course … must have been quite the sight for the neighbours! But hey, always look on the bright side right? I must have recovered 300-400 seeds … free seeds man! I've been using some to experiment with germination conditions, so I know a good chunk of them are viable and will sprout. I realize it'll be crap shoot wrt male/female, and may have to be on extra guard for hermies, but hey, these seeds may come in real handy if the world gets any crazier. Not a bad haul from 3 seeds that were originally freebies that came with the purchase of some autos.

apologies for the length … figured I owed y'all some catchin' up.

Thanks for reading, and thanks in advance for any input with respect to sterilization and re-use of media.

p.p.s.: How's my weather? 5 months later, still snow on the ground and freezing out, for frig's sake. On a positive note, makes social isolation and distancing a little easier to take.

Stay safe everyone … stay healthy … stay home … and please take this in the spirit intended … stay away.

[Rwise]

I had a gnat infestation, I re-potted the plants in soil I had baked at 250*F for an hour or so, then bake that soil (same 250*) she came out of for the next plant. The gnats are now dead, DE mixed in the soil also, some Fish Sh!t and Voodoo Juice to help restart the soil.

[Toker1]

Viruses can live at temps under 248F and it needs to be held above that for 30 min or longer to sterilize. This is a good method. And I am a big fan of fish sh!t.

[aintdedyet]

Thanks for the prompt reply Rwise … sounds like dirt might be on the menu in the near future.

Not sure I can get the products you mention, but I've been experimenting with this stuff during my current grow.

https://mygoodgreen.com/pro-grow/

I'm not sure but it may serve to rejuvenate a sterile media. I've used it both by initially charging my soil-less media prior to planting, and as a soil soak after fermentation with honey. Not sure if it's going to make a difference to the current yield results, but it may help get the next grow going.

Anyone with experience with this product?

thanks again

[Rwise]

I have not used that, any beneficial microbial stuff, those are what I have on hand
Just put a batch of ground leaf into the oven for an hour! Transplants later today.

[Cali]

Maybe try going with an organic”living soil” I have over a year now with the same soil. It’s still going good. I’m just saying because that will allow you to reuse your soil no need to buy new soil after every grow. And no extra work like testing ph the runoff and all that other none sense that comes with using bottled nutrients. If you are going to use that soil if you have it available mix in some diatomaceous earth and let it sit in a bag for a day or 2 with no air that should help. Or just cover the top layer about an inch tick of DE once it’s in your pot shouldn’t have any issues. I would throw any dirt in my oven. I matter what.

[Canuck147]

Might as well use what ya got - I did - have 4 autoflowers in recycled soil. Al I did was give it a flush. Sprouts have sprung up in it and they're doing alright.

[Gluteous]

Personally I wouldn't unless I had to. Dirt is cheap and you'll know it's clean and if your grow shop is open they'd love to see you about now, I'm guessing.

[aintdedyet]

Thanks all for your input. State of emergency declared and all non-essential shops closed, so went with the recycling option. Government run weed and alcohol stores have been deemed essential though, so that's a good thing I guess.

Went with 1 h @ 350F, with a stir half-way through. Minimum internal temp. of 165F … figured I was cookin' meat in one form or another. Not as stinky as I thought it might be, nor as messy.

Took a look at 40X mag. no signs of life. Will let y'all know if I have bug issues as the next indoor grow progresses.

stay safe folks

[FunkyButtLovin]

Sorry to hear about your store closing temporarily. My local is part of a big milling and animal feed place so it will not be closing down thankfully.