Great read on rockwool. Excellent tips in here.

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PhatNuggz

PhatNuggz

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Lol its rock, your plastic bucket will be far more poisonous to the enviroment. To each his own though

I've been using the SAME buckets for 3+ years with NO sign of breakdown

Seem harmless enough Rockwool Rockwool is a horticultural growing media made from the natural ingredients Basalt rock and Chalk. These are then melted at 1600° C into a lava which is blown into a large spinning chamber, which pulls the lava into fibers like "cotton candy.". Horticultural Rockwool growing media is primarily available in two general formats.

BUT

It’s Not Environmentally Friendly
I believe in environmental sustainability – it’s one of the reasons I’ve chosen to grow hydroponically. Rockwool doesn’t score well on the environmental scale. It’s not a natural material. Manufacturers use combine chalk and rock and then heat them up to around 3,000 degrees Fahrenheit. Next a stream of air is blown through it, resulting in extremely thin fibers of the rocky material. As the strings are blown out, they bunch together and form the material that you see for sale at the local hydroponics store.

Basically, they are taking two materials that are 100% natural (chalk and rock) and turning them into a hybrid material that will remain in that form forever. When you throw away your old rockwool it’s going to sit in a landfill looking just like that for a long, LONG time. If you absolutely insist on using it, try to save your rockwool in between your growing season and reuse it.

It’s Not Healthy To Be Around
Not only is rockwool unfriendly to the environment – it’s also potentially harmful to your health. New blocks can contain a lot of dust and loose fibers that can get in your eyes, mouth, skin and lungs. It’s similar to asbestos in the sense that the little fibers can lodge themselves in your lungs if you’re working with it a lot. It may not be as toxic as asbestos, but why take the risk? Not something that I’m willing to gamble with if I don’t have to – there are plenty of other hydroponic media choices! If you’re using rockwool, you should be using a mask, goggles and gloves when you work with it to protect yourself.
 
H

Hominine

1
1
I've been using the SAME buckets for 3+ years with NO sign of breakdown

Seem harmless enough Rockwool Rockwool is a horticultural growing media made from the natural ingredients Basalt rock and Chalk. These are then melted at 1600° C into a lava which is blown into a large spinning chamber, which pulls the lava into fibers like "cotton candy.". Horticultural Rockwool growing media is primarily available in two general formats.

BUT

It’s Not Environmentally Friendly
I believe in environmental sustainability – it’s one of the reasons I’ve chosen to grow hydroponically. Rockwool doesn’t score well on the environmental scale. It’s not a natural material. Manufacturers use combine chalk and rock and then heat them up to around 3,000 degrees Fahrenheit. Next a stream of air is blown through it, resulting in extremely thin fibers of the rocky material. As the strings are blown out, they bunch together and form the material that you see for sale at the local hydroponics store.

Basically, they are taking two materials that are 100% natural (chalk and rock) and turning them into a hybrid material that will remain in that form forever. When you throw away your old rockwool it’s going to sit in a landfill looking just like that for a long, LONG time. If you absolutely insist on using it, try to save your rockwool in between your growing season and reuse it.

It’s Not Healthy To Be Around
Not only is rockwool unfriendly to the environment – it’s also potentially harmful to your health. New blocks can contain a lot of dust and loose fibers that can get in your eyes, mouth, skin and lungs. It’s similar to asbestos in the sense that the little fibers can lodge themselves in your lungs if you’re working with it a lot. It may not be as toxic as asbestos, but why take the risk? Not something that I’m willing to gamble with if I don’t have to – there are plenty of other hydroponic media choices! If you’re using rockwool, you should be using a mask, goggles and gloves when you work with it to protect yourself.

A metric ton of misinformation here, from a poor understanding of microplastics and its externalities through the particulate size of Grodan and the role rockwool can play in composting. Unsurprisingly, this brand of fear mongering is provided unsourced.
 
AnselAdams

AnselAdams

Supporter
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A metric ton of misinformation here, from a poor understanding of microplastics and its externalities through the particulate size of Grodan and the role rockwool can play in composting. Unsurprisingly, this brand of fear mongering is provided unsourced.

Hominine;

You have made a bold statement but have failed to provide any supporting evidence. Please be so kind as to provide factual rebuttal so that others on the farm can judge for themselves. I think that reasonable, rational debate needs documented supporting sources on both sides. The pros and cons of RW have been debated in many, threads in farm. Some containing more fact than others. PhatNugzz has provided us with his sources in previous posts, we look forward to reviewing yours as well.

Thanks


 
cemchris

cemchris

Supporter
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Rockwool that we use from growing is made from basalt rock. There are many ways and materials used to make rockwool but specifically from growing its basalt rock. Most rockwool in Europe is recycled. In fact Grodan will pick it up from your facility to recycle it. Sadly they don't have a program like that in NA for all the big greenhouses (AFAIK). The alternative to Grodan is coco. A lot of the neg feedback comes from the coco industry. Coco has it's own problems with sustainability, pollution , and water usage.

The big problem you are talking about is alternatives. Large scale greenhouses it pretty much comes between coco, rockwool, and perlite. You can't really run something like hydroton in acres of greenhouses. Rockwool and coco have their own pluses and minuses.


As far as health effects goes. All of these studies look at the application of rockwool as an insulation and production for that purpose.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2711883/ <--- all the half life tests on rats of inhalation.
"The International Agency for Research on Cancer (IARC) classifies RW as group 3: limited or immature carcinogenicity in animals, and unclassifiable carcinogenicity in humans

"Group 3: "Unclassifiable as to carcinogenicity in humans" There is no evidence at present that it causes cancer in humans.
IARC definition and list of compounds "

Basically rockwool dust has the same health effects as coir dust


I'd be more worried about the plastic totes and the material used to make all the hoses ect in a grow then I would be about rockwool. Also in the form we use rockwool, applying irrigation to, the likely hood of loose dust in fibers is almost nill since it is prewashed and conditioned after production, unlike production for insulation, and then constantly washed and irrigated which will remove any fibers or loose material down a drain and not into the air vs in something like using it as overhanging insulation. Also when using it in cube/slab form the cubes are rarely disturbed. Slabs are an even better choice since they are usually contained completely in a covering. The only thing that may kick up fibers/dust is when using loose rockwool filling pots since that is ground up. I'm not sure how much rockwool you have run but every time I get a case of 6in cubes there is pretty much nothing left over in the box afterwords with 64 cubes sitting on top of each other. Way less then all the coir dust everywhere from bagged coco.
 
Allouise.G

Allouise.G

6
3
Hi guys, I'm an old fashioned grower that's had alot of experience in growing outdoors unknown strains back in the 80's and 90's, I'm now giving modern ways a go but without too many costly in thought about changes, so out of 24 seeds Im growing I've desided to give Rockwool a try, I use my brain and have only tried 1 seed in Rockwool and thankfully I did because it's just not working for me, I think it would be silly for anyone to change completely and risk several seeds and alot of cash on trying too many at once for their first try at it, so the seedling just legged it! it germinated well grew so talk it almost ran away and that's about it, I seriously didn't think it would servive much longer so I thought I'd try something radical before I gave up and risked taking it out of the slab, which is not easy once it's in there, so I added some good quality seedlings soil to the top of the slab and built it up around the long fragile stem and watered the soil's nutes into the Rockwool, by the next day it was no longer legging it and growing foliage at a rapid pace, it's saved and is still in the Rockwool, my intention now is to gently cut as much Rockwool away from the outer edges without damaging the roots and then placing it in a nice sized pot of Soil, Coco, and perlite mix and go from there, it may not be a complete and permanent fix but as a temporary life saver it worked for it, thankfully I only tried one seed or I'd be in a sorts of trouble, I wouldn't recommend anyone simple changing their medium to Rockwool for all their entire yearling grow without trying one or two first as it could be a costly and disastrous result for what are now expensive seeds compared to the old days when we'd find 100's in our bags free and try anything to get larger plant's and yields, good luck to those willing to risk changing up to Rockwool with no experience, it's not an easy medium to work with at all , I'm glad I gave it a go, I wouldnt have known without a try
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Jeremey

Jeremey

45
18
I’m new to Rockwool. Lots of good info on here. I have 2 gallon flood/drain buckets. Right now I’m trying to dial in how often I should flood. I’m using GH3 at 3/4 strength. Sitting at 650ppms in the beginning of week 3. Leaves aren’t perfect yet. It also seems a little wet in those buckets. I started at three floods, then two, was going to try once a day. The PPMs are not rising, or really lowering either. PH is stable. Any info on your experience with this would be appreciated
 
Relentless799

Relentless799

1
1
I have been using 6in. Hugo and Biggie blocks for 10+ years and Capulator’s post is the most straightforward info I have read.
 
klapperkaak

klapperkaak

2
3
I've been using the SAME buckets for 3+ years with NO sign of breakdown

Seem harmless enough Rockwool Rockwool is a horticultural growing media made from the natural ingredients Basalt rock and Chalk. These are then melted at 1600° C into a lava which is blown into a large spinning chamber, which pulls the lava into fibers like "cotton candy.". Horticultural Rockwool growing media is primarily available in two general formats.

BUT

It’s Not Environmentally Friendly
I believe in environmental sustainability – it’s one of the reasons I’ve chosen to grow hydroponically. Rockwool doesn’t score well on the environmental scale. It’s not a natural material. Manufacturers use combine chalk and rock and then heat them up to around 3,000 degrees Fahrenheit. Next a stream of air is blown through it, resulting in extremely thin fibers of the rocky material. As the strings are blown out, they bunch together and form the material that you see for sale at the local hydroponics store.

Basically, they are taking two materials that are 100% natural (chalk and rock) and turning them into a hybrid material that will remain in that form forever. When you throw away your old rockwool it’s going to sit in a landfill looking just like that for a long, LONG time. If you absolutely insist on using it, try to save your rockwool in between your growing season and reuse it.

It’s Not Healthy To Be Around
Not only is rockwool unfriendly to the environment – it’s also potentially harmful to your health. New blocks can contain a lot of dust and loose fibers that can get in your eyes, mouth, skin and lungs. It’s similar to asbestos in the sense that the little fibers can lodge themselves in your lungs if you’re working with it a lot. It may not be as toxic as asbestos, but why take the risk? Not something that I’m willing to gamble with if I don’t have to – there are plenty of other hydroponic media choices! If you’re using rockwool, you should be using a mask, goggles and gloves when you work with it to protect yourself.

I just have to reply to this.. Rockwool is so much more benign then you make it out to be. Sure it's not 'natural' or organic and won't break down into compost, but it will mechanically break down into smaller pieces and eventually to dust. So is it really a problem to bury used rockwool under ground? I don't think so, as long as you remove the plastic wrap. The plastic wrap is a perfect candidate for pyrolysis. Most rockwool slabs that are used commercially are recycled either in compost or in the Netherlands they use it to make bricks.

Then there's my personal experience with rockwool.. I did an outdoor grow with tomatos and cucumbers on a few rockwool slabs with drippers. I was very surprised to find worms living inside the rockwool slab at the end of the season. They really seem to love the combination of moisture, oxygen, dead roots and grit from the rockwool, which they need to digest food. They are naturally capable of tolerating high EC from the minerals in soil, and hydroponic nutrients don't seem to harm them. I do wonder about the effect of synthetic chelates on them, but so far so good.
After cleaning up I tore up the slab and tossed it in the worm bin and the worms are actually most concentrated in the rockwool pieces believe it or not.
After a while the rockwool pieces get warm from a composting process. Again this combination of air, moisture, organic material and mineral nutrients is an amazing substrate for a hot composting process. Fast forward half a year, the worms broke down the rockwool into much smaller pieces. I sifted the compost and am now growing some vegetables and autoflowers with this compost as top dressing and they are doing excellent! Worms also loving life, more so then ever it seems.

One very solid arguement that you could make against rockwool is that it takes alot of energy to produce, as opposed to coco coir for instance. But then coco coir has to be hauled in on ships that use massive amounts of diesel... So if the rockwool foundry is more local, and for me most are, it could be better for the environment after all. So ultimately I think it's going to be similar in environmental impact.. I really don't see any objections to using rockwool.

BTW I dont know where you got your information from but it makes you sound like an overly worried mom.. There's a lot of warnings there without a real explanation of the actual danger. Fine dust of anything is a potential hazard for the respiratory tract and rockwool is far from the worst (I'm thinking about glass fiber insulation now, ughh) and it's kept wet most of the time, so there's no dust when it's actually in use.
 
JASONBROTHER

JASONBROTHER

206
43
so in my efforts to maintain a clean environment utilizing rock wool i have come across an idea that is working well so far.in the past i ran six inch blocks on top of coco mats with good results as the coco acts as a light proof breathable barrier to allow more root mass to grow beyond the block and increase over all plant size. coco is not a treated substance and carries gnats along with it, this sucks and is something i no longer deal with. i called envirotech green houses and spoke with a guy named josh, he was more than helpful in getting me a cut off of their light proof breathable fabric that comes as a four layer product. i pulled it apart to make a two layer product. i cut 6 inch holes where my blocks are spaced as well as holes for the top feed drip lines. so far it is doing what i want, roots are growing and i am maintaining moisture so they don't get air pruned. i will post mrs pics as time goes on. the root shots are spaced three days apart to show the growth rate.View attachment 434416View attachment 434417View attachment 434418View attachment 434419View attachment 434422View attachment 434423View attachment 434424
Bro,
It's my first time growing, and I started using rockwool. Because I could buy any products of floraflex in my country, and the only nutrient solution I can buy is the emerald harvest, so I just use two 6-inch rockwool to stack up. At present, the flowering period is the second week,

It gives me the feeling that the EC Value of rock wool must be well controlled. Compared with aeroponics and hydroponics, the EC Value of rock wool is the lowest. Moreover, it's difficult for me to control my watering at the flowering stage, because I can only buy very simple automatic watering equipment
 
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JASONBROTHER

JASONBROTHER

206
43
In my new air-conditioning system, the temperature in the tent reaches 30-34 ° in summer, CUZ I only get one plant, it is impossible to directly turn on the air conditioner in my home, so I bought this portable air conditioner online. For humidity, I can only buy a dehumidifier ,The dehumidifier and air conditioner operate at the same time, plus carbon dioxide equipment, so as to maintain the most suitable environment,

I personally recommend to use tap water (ppm 160). from germinates to the beginning of the Veg ,and the fourth week of the flowering period.

because the calmag is relatively small at that stage, and the ec value is easy to explode at the beginning of the plant(If you add nutrient solution and calmag at the same time),
and i only use RO water and Silicon (5ml / per gallon) and calmag (5ml / per gallon) during the late Veg to the first few weeks of flowering
 
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