Perlite for Seedling Media

Hey everyone!

Long time… Radio silence… Sorry :face_with_peeking_eye:… So we’re finishing up a nice Lemon Galric OG (few hiccups but all goodish).

Now on to our experiment!

Goal: Grow from seed using neoprene collars as final home in rdwc.

Problem: Can’t really see just dropping a popped bean in a collar by itself.

Brainstorm: Find media that can sustain life, be easily washed off for transplant, hold moisture without over saturation (root rot), hold nutrient decently, stable, does not compact to much and provides air to roots.

Media: After a bunch of consideration a medium or fine grade Perlite.

Reasoning: Seems to check the boxes above (hopefully :grin:).

Began experiment last night a 6:00pm.

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8/15/2024 6:00pm
Prepped fabric pots with medium grade perlite.

Dry weight once filled was 3.7oz

1-15 min soak/top feed in RO (0ppm and 7.4ph)

Check run off water (cloudy, 0ppm and 7.4ph)

Drained weight of perlite/fabic bag 12.0oz

Repeated same test (15min soak/top feed, run off test, drained weight)

Drained weight 11.9oz, 0ppm (same) and 7.2ph (down 0.2)

No noteable compaction/moist top couple inches

Letting sit under grow light at seedling intensity overnight to record losses.

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08/16/24 6:00am

No compaction. Media still looks clean.

Weight is 11.2oz as of 6:00am

Total loss 0.7oz in 12hrs.

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08/16/2024 12:00pm
Top 2 inches feeling cool and kind of moist.

No settling of media.

Weight as of 12:00pm 10.8oz

Loss since 6:00am of .4oz

Loss since 6:00pm (18hrs) 1.1oz

To be continued this evening…

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08/16/2024 6:00pm
24hrs since start

Still under lights on low settings 18 on and 6 off

Top 2in or so cool but dry feeling, then slightly moist, followed by moist.

Not compacting/seems to be drying very evenly from top down.

Weight as of 6:00pm (24hrs) 10.4oz

Weight loss in last 6hrs 0.4oz

Weight loss in last 12hrs 0.8oz

Weight loss in last 24hrs 1.5oz

Continue letting dry…

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growing a weed my friend it is not hard :slight_smile: just saying

I did read what you posted

all the best and grow well

Dequilo

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We’re kinda nerds :nerd_face: lol

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Fine or medium grade Perlite seems like a solid choice for your needs. Looking forward to hearing how it works out in your RDWC setup.

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08/17/2024 6:00am
Still under lights
Feeling cool and dry throughout
Safe to consider dry and in need of resoak/top feed

Weight as of 6:00am (36hrs) 9.6oz

24hr to 36hrs seems to be a sweet spot for water/feeding (until roots developed)

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08/17/2024
Preformed run off test on test perlite
Ph was 7.3 and 0ppm
No noteable difference between beginning and now
2 total soaks/topfeeds

NO NOTEABLE DIFFERENCE IN COMPACTION/PH/PPM

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Update on the perlite experiment. So far so good! Day 8 update w/ride along of previous 7 days.

Strain: African X Princess 88

Seedlings media: Soak/Paper towel/100% medium grain perlite

Nutes: R/O and Cropsalt (always ph’d between 5.5 to 6.0)

Environmental Driver: Mainly VPD driven with focus on 75%+ humidity

Day 1: 8hr seed soak in R/O moved to damp paper towel in darkness method (paper towel kept moist between 2 plates on heat mat @ 80°f)

Day 2: 3 of 4 had small tap roots.

Day 3: All seeds had developed at least 3/4" tap roots most closer to 1.25". Moved to medium grain perlite in fabric pots and into humidity dome at 40% light (ionbeam ac infinity bars/dome). Buried a little deep about 3/4" to 1" because we are aiming for a longer stronger tap and the perite is looser than plugs by far.

Day 4: No change… That had not broken out of perlite yet. Fed 80ml of cropsalt/R/O blend per pot seedling strenght at 16% strength.

Day 5: 2 had popped from perlite.

Light 40%, RH average 82.5% Temp average 74°f VPD average 0.52

Day 6: All had popped. Fed 80ml of cropsalt/R/O blend per pot seedling strenght at 16% strength.

Light 40%, RH average 81.5% Temp average 74.6°f VPD average 0.55

Day 7: Growing first true leaves emerged/emerging. Fed 80ml of cropsalt/R/O blend per pot seedling strenght at 16% strength.

Light 40%, RH average 82.5% Temp average 74°f VPD average 0.52

Day 8 picture: They’re going good!

Not trying to be critical or anything…but what is the point in this? To see if you can grow in pure pearlite? And I don’t know how you could have cloudy water and 00 ppm on particulates? And from my experience, you are going to wind up with a bunch of pearlite stuck to all the hair roots when you go to transplant Just sayin.

Marty

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I gotcha and good points! We keep getting issues with fungus gnats with the rapid rooters over time and this time we are aiming to run RDWC in just collars to get rid of them/clean things up.

We aren’t currently looking into cloning and are planning to grow in perlite until the best 2 have 5 nodes or so. From there we will remove some of the lower branches and transplant into the system. Hopefully with the bottom stripped out they will develop more roots like a tomato plant and take off. Once settled in their new home, we’ll top/train and see where it goes from there.

In theory fingers crossed… the perlite will wash off nicely and we’ll have strong and healthy plants with a clean system without cloning.

The 0ppm and cloudy water was odd… But thats what the meter read. Maybe like a inert stone or the vessel itself in water it doesn’t contribute to ppm.

Hopefully, it cleans up nicely and we’ll see if it works. It’s all a learning experience for us and hopefully it goes well :grin:

Day 18 from very start update/completion

*Strongest 2 were kept to grow to flower

Goal: Clean transition from seedling to medialess RDWC
Start media: Medium Grade Pelite
End media: Medialess (Collar)

Beginning nutes: Cropsalt @ 16% seedling strength
Ending nutes: Cropsalt @ 125% seedling strenght w/1 foliar treatment of Dune

Environmental target: Early on 0.5 VPD worked up slowely to 0.8 VPD

Lighting: Starting ac infinity ionbeam 16 (built in humidity dome) Ending last couple days with kind led x330 at 25% @ approx 16inches

Findings: Seedlings did great with everything. Started with a short soak, then paper towel method and finally onto perlite. Definitely feel that light nutes helped from the start as perlite is inert. Kept nutes at 16% until firts true leaves then started working up in strength from there. Was going to keep going until fifth node but roots started pooping out the bottom of the bags.

Transpant process

Prep: container w/RO water for root rinse, wet wet wet paper towels w/RO to rest plants on after rinse, sterile scissors, gloves.

Process: Cut open bags and carefully remove plant. Rinse in RO changing water often. Once clean set on wet paper towels and cover roots to protect from light/keep moist. Move to collar and set in new home.






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Note… Did sustain a decent amount of root damage from where the plants grew through the bag. Hopefully they recover well abd we’ll see!

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Well one…I’m surprised that the pearlite didn’t stick to the roots as pearlite is porous. But it looks like it came off just fine. Good looking roots! Suggestion next time use plastic for the container, no need for fabric bags as the pure pearlite offers plenty of aeration and at that small stage you don’t need root trimming you need the best root mass you can get.

Now you have gotten me to thinking. And I know that it is already done with Rockwool, but I wonder how they would do with a ebb and flow system in pure pearlite from start to finish? They certainly wouldn’t starve for oxygen in pearlite as the pearlite itself is expanded rock and porous, and in bulk provided plenty of air spaces. I’m sure someone has already tried it.

It would certainly be a very light container. Sometimes I think to much lol.

You could call it RDWP Recirculating Deep Wet Pearlite lol.

Marty

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Hmm wonder if u can stich some velcro on the bags and reuse them for this purpose just have to peel the velcro to get the plant out. Lol. Nice work. Im shocked the perlite cane right off the roots ive had several pieces of perlite be stuck to the little feeler roots in the pots when i scope roots here and there. May have to try this out.

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Sorry stuck at work right now but definitely want to dive into everything a little deeper when i get off. So I’ll be back lol!!

Here’s a little read that we used when thinking about trying this out.

The Water-Holding Capacity of Perlite - Perlite Institute(Fig.

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Great info!

Well that pretty much enforces what I already knew about Pearlite. And that also pretty much answers the question if it could be used as a singular grow medium just as Rockwool is. The answer being yes.

Now personally I use a 50/50 mix of coarse Pearlite and Coco coir in my organic grows, it is actually not 50/50 as I put a gallon of both worm castings, and a gallon of organic compost into that 8 gallon fabric pot, as well as quite a bit or organic fertilizers as well. Between high nitrogen, general balanced, and flowering organic mixes (Gaia Green) I also add Azomite Humic acid, and Kelp meal. All of that to feed the microbes.

I also spritz the plants using Organic Fulvic acid in a 1/2 teaspoon to one gallon mix to cause the plants to produce more budding sites. I do this about 4 times during the veg.

The fact that it is 100% organic fertilizers that must be broken down through soil microbes, it is very hard to overfertilize. I use 9 full cups of the various organics in a 8-9 gallon fabric pot, I wind up with around 11-12 gallons of mixed soil after adding all the amendments. I’m thinking about adding hard wood charcoal next grow (also known as Bio-Char) the new trendy name for oxygen deprived burning of organic waste to produce charcoal lol. I won’t use regular charcoal, as that contains a lot of coal.

Now for me, I wouldn’t use this method as it is too hard to get 100% organic fertilizers for a application like this that don’t clog everything up. And it would take me right back to having to fiddle constantly with PH.

But for those interested in Hydro, or ebb and flow or any of the other methods, this might very well be a fantastic way to approach a good soilless medium with superior aeration. One could probably approach the growth rates of DWC using this as the aeration would be fantastic.

Marty

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@sssportsmfg & @Mark0427 We like both those ideas! They did have a couple slow first days after the transplant but they seem to be taking to everything very nicely now.

Maybe later on down the line we may go organic but so far we’re really liking sterile and yes we do see that the perlite may not get along well with organics in the long run.

They are taking off now and roots are taking off from where it used to be stem. So were really liking this setup.

We are trying out Cropsalt/RunClean at their set schedule and adding silica via Dune foliar spray.

We’ve been slowly creeping up vpd to 0.9 to 1.0
Temp 75ish RH 68ish little drift here and there.


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