Rice hulls mixed with coco

[ED-209]

I've been using silica for ages in liquid form - it's not cheap and sometimes annoying to work with. Though I am impressed with the Med Tek silica.

Anyhow, seeing some info from Dr Bugbee on rice hulls got me curious about adding them to coco (either straight or in a stock 70/30 perlite mix). I searched and found people using them in soil mixes, but not specifically with coco in a DTW system. Rice hulls seem fairly easy to come by in brew shops. On the Dr Bugbee AMA it mentions "He now uses 75% peat, 13% vermiculite, and 12% rice hulls" as their base media in the lab. It's a starting point and subbing in might work. Unsure of if that might impact other factors - water holding and nutrients.

Anyone doing this instead of using aqueous silica? One less bottle is appealing, and seems cheap.

Cheers!

 

[Sedge]

I wonder how much silica is released in a three month grow ,,
and whether the amount of silica is going to be enough to make much of a difference ,,
Then you have the Arsenic factor ,I wonder how much of that gets released and if it’s enough to worry about.


I also wonder if it would be more quickly available to the plant if you burnt the husks and used the ashes,,Silica will still be there but same with arsenic and any base metals ,,

matter of fact rice husks sound pretty toxic for an accumulator plant like cannabis,,don’t know why it’s added to organic mediums in the first place, or any soil mix that is marketed for accumulator plants I mean isn’t “organic“ meant to represent something we can consume and feel comfortable with thinking that it has no toxins in it ? Well thats what I thought anyway.

The more I think about it ,the use of rice husks sounds pretty fucked up.

I wonder if it’s worth pulverising quartz to fine powder is worth
doing, I figure over time it is if you continually use the same medium . And that’s probably one of the cleanest ways to introduce silica without paying for bottles,,




This post is bought to you by the word WONDER.

Which peculiarly enough is an anagram of wrendo, which isn’t even a word and makes absolutely no sense at all.

 

[ED-209]

I wonder how much silica is released in a three month grow ,,
and whether the amount of silica is going to be enough to make much of a difference ,,
Then you have the Arsenic factor ,I wonder how much of that gets released and if it’s enough to worry about.

I did water chem at uni, and spent a fair bit of time looking at solubility of silica... with regard to using crushed quartz - that wouldn't likely contribute much to available silica since you need very high alkalinity to dissolve silica from solid.

The arsesnic content of rice hulls - now that I hadn't noticed mentioned. That could be an issue indeed. I'll have to look into that one and see what the numbers are like. I'm certainly not of the view that organic is best - I love synthetic and am comfortable with chemistry. The only temptation is to simplify things day to day more than anything.

I can't recall for arsenic since I didn't look at it much (mostly looked at cadmium and lead), but would think it would fall into similar category of being bioavailable at specific pH....which is probably in the acidic side...which is probably close to what we use for nutrient feed (or at least close enough to). Either way, this isn't looking good...

That said, people are using ricehulls in beer brewing without consideration of arsenic. So should investigate that side and see where that lands, as that would be more direct and problematic than via bioaccumulation in a plant as an intermediary...

As far as amount of silica released by the hulls, from what I read 20ppm silica is all that is required, so it isn't a lot to release over the period of the grow. What might be harder to gauge is how much it is consumed by the end if reusing the media...

Lots to ponder and wonder of xmas day

 

[itchybro]

the jury seems to be still out

arsesnic , highly toxic metalloid whose elevated concentration in plants is a serious concern. In addition to its toxic effects , limits the uptake of minerals that are necessary for plant growth and general physiological functioning

Arsenic (As), a naturally-occurring metalloid, is not essential for plant growth, but it can accumulate in plants to toxic levels. As a result, it can enter the food chain and pose health risk to humans. Multiple mechanisms are involved in the uptake and metabolism of As in plants.

Is arsenic a nutrient?
It's possible that it's an essential trace element for humans, but if so, it's going to be pretty far down there in the trace. But it really does seem to be essential in some smaller mammals, so it's not that crazy an idea.
-----------------------------------------------------------------------------------------------------------------------------------------------

Why is arsenic bad for soil?

Mechanism of Arsenic Metabolism, Transport, and Detoxification in Food Crops. Higher concentrations of As in crop soil and groundwater may result in increased crop loss and catastrophic health effects in humans. Rice grains have been shown to accumulate 2.24 mg kg−1 As compared to other main food crops

-----------------------------------------------------------------------------------------------------------------------------------------------

Allot of root crops will accumulate arsenic in the skin of the root veg , carrot , potato , etc , so often best to peel them despite the many positive benefits of eating the skin , also older treated pine sleepers can have arsenic in them so prob not the best choice for veg beds , my understanding though is modern day treatments of pine do not contain arsenic

 

[ED-209]

the jury seems to be still out

Allot of root crops will accumulate arsenic in the skin of the root veg , carrot , potato , etc , so often best to peel them despite the many positive benefits of eating the skin , also older treated pine sleepers can have arsenic in them so prob not the best choice for veg beds , my understanding though is modern day treatments of pine do not contain arsenic

I'll do some reading and see what I can deduce from the evidence. A quick look yielded some interesting points to investigate further.

It is true we consume small amounts of it from food sources. I also wonder about trace amounts in synthetic nutrients as I'd imagine there would be some trace level in those. So we need to determine critical levels for presence, uptake and consumption... cool, been a while since I did some decent research. I'll report back and get the buy in

 

[ED-209]

For those interested, this is a Bugbee paper from this year discussing silicon soil amendments including rice hulls:

Dissolution of Silicon from Soilless Substrates and Additives

Silicon (Si) is a beneficial element that is usually ample in mineral soil solution, but it is minimally bioavailable from soilless substrates. Several Si additives are commercially available, but the rate of dissolution of Si is not well-characterized. The ideal additive would steadily release...

journals.ashs.org

It isn't a great paper - with regard to heavy metal issues, they only reference another study on basil which isn't relevant and they don't test it directly. A real shame - hopefully something they look at in follow ups.

From a read over recent papers seems to say that arsenic is taken up in rice by the same root pathway as silicon, hence it's accumulation and a lot of work is being done to prevent this by supplementing silicon in the soil to dominate up take. Would need to see if the root pathway is shared in eudicots. There still seems to be a lack of detailed info relevant to us on this though. I'll keep reading, but yeah, for the moment I might put this on hold and just keep with the aqueous stuff

 

[OZIOZIAUTO]

No rice hulls for me , simple

 

[OZIOZIAUTO]

Live worms in the medium and feed them it works

 

[ED-209]

Live worms in the medium and feed them it works

Live worms in a coco DTW? I would have thought they wouldn't thrive in such conditions. Or are you talking about living soil?

 

[R3za92]

Photo-Finish™

Enhance Plant Resilience with Photo-Finish™ Silica-Based Foliar Fertiliser. Strengthen Cell Walls, Deter Herbivorous Insects and Promote Photosynthesis. Photo-Finish™ Combines the Brix-Building Benefits of Silicon with Kelp, Humic Acid, and a Significant Potassium Boost. Ideal for Vegetative Growth.

nutri-tech.com.au

Try this instead of the med-tek. It’s $28 for 1l and the dosage is pretty damn low because it’s ag grade so will last you a fair while. It’s also got kelp and humic acids so a pretty good quality product as with pretty much all the nts gear.

My recommendation is to foliar spray it per the instructions as it will aid in the uptake. I’d also recommend their cmb trio (mostly to supplement calcium and boron which are often lacking in most grows without showing a deficiency, if your stems are hollow your low on calcium/boron or both) as well as a few others like their brix fix etc. if your willing to drop the cash as not all come in 1l bottles. If you don’t want to buy 5l dm me and I’ll sell you a litre of any of the ones I have sitting here.

 

[ED-209]

Photo-Finish™

Enhance Plant Resilience with Photo-Finish™ Silica-Based Foliar Fertiliser. Strengthen Cell Walls, Deter Herbivorous Insects and Promote Photosynthesis. Photo-Finish™ Combines the Brix-Building Benefits of Silicon with Kelp, Humic Acid, and a Significant Potassium Boost. Ideal for Vegetative Growth.

nutri-tech.com.au

Try this instead of the med-tek. It’s $28 for 1l and the dosage is pretty damn low because it’s ag grade so will last you a fair while. It’s also got kelp and humic acids so a pretty good quality product as with pretty much all the nts gear.

My recommendation is to foliar spray it per the instructions as it will aid in the uptake. I’d also recommend their cmb trio (mostly to supplement calcium and boron which are often lacking in most grows without showing a deficiency, if your stems are hollow your low on calcium/boron or both) as well as a few others like their brix fix etc. if your willing to drop the cash as not all come in 1l bottles. If you don’t want to buy 5l dm me and I’ll sell you a litre of any of the ones I have sitting here.

Awesome thanks for the recommendation. I've bought fulvic acid from NTS before. Their stuff is quite economical and I'm down for ag grade products with clear guaranteed analysis!

I've also wanted to get more into foliar spraying - as I've done with the fulvic, but that photo-finish product looks really neat, same with the others you mention. Do you use them all and rotate and or use at targeted intervals? And then take it you don't add similar things (fulvic, silica etc) to your res?

 

[R3za92]

Awesome thanks for the recommendation. I've bought fulvic acid from NTS before. Their stuff is quite economical and I'm down for ag grade products with clear guaranteed analysis!

I've also wanted to get more into foliar spraying - as I've done with the fulvic, but that photo-finish product looks really neat, same with the others you mention. Do you use them all and rotate and or use at targeted intervals? And then take it you don't add similar things (fulvic, silica etc) to your res?

Depends on the product, I mostly run a cycle of foliar spraying spread over a 1-2 week period, the brix fix I’ll add to my res especially during flowering but also foliar once every couple of weeks. Foliar spraying is just more effective and targeted and you don’t need to worry about compatibility issues like fallout or uptake issues.

For example calcium is far easier for the plant to uptake as a foliar than via the roots and I run 3 different calcium products on a 2 week rotation (cmb trio (every 3-4 days because boron), phos-life once a week (micronised calcium phosphate for a calcium phosphorus boost which helps with phos uptake issues and combats purple stems) and a non nts micronised calcium carbonate every 2 weeks or so (nts make one as well but I got one from the states to try before I started buying nts gear and I’ve still got plenty left). I’ll run that cycle all the way up until week 2-3 of flower once I’ve got buds staring to set up.

Haven’t had a hollow stem since starting with the calcium products and every time I’m lax with the phos life my heaviest feeders get purple stems back within a week on new growth.

The photofinish I’ll spray once every week or so normally the day after the micronised products

The next products I’ll be buying from them will be their hydro shuttle (but I’ll wait until I run out of the house and garden cocos base I’m currently running and switch to ag grade base system) and a few of their microbial products. Will also probably grab a bottle of their cloak spray oil to add in with my veg foliar products to increase their effectiveness.

 

[ED-209]

Depends on the product, I mostly run a cycle of foliar spraying spread over a 1-2 week period,

Thanks so much for sharing all the detail. It is super helpful to get a picture of it all, really appreciate it. I'm gonna give it a solid look now, cheers

 

[frankreynolds]

I'd skip the rice hulls due to potential for heavy metal contamination and Cannabis being a hyper accumulator of said heavy metals.

If you can find it locally, which I haveen't been able to but havent looked hard you can use Calcium silicate mixed(wollasonite) mixed in with the coco. Should give a nice slow release of silica and calcium.

I'd just stick with NTS silica personally, as other have mentioned. I got 5L of there concentrated potassium silicate for 90 bucks years ago using it at 0.1ml per L in my res gives me 20 ppm of silica approx in solution