Growing with rockwool as a medium

[JDMase]

So I've seen some videos on YouTube of successful rockwool grows and wondered what your views are on it.

Have you tried it?
Do you like it?
If so, why or why not?

Also share your set ups and nutrient feeds if you like.

I'm going with 3" cubes going into pots full of the tiny cubes probably a couple litres each. Feeding with gh flora nova. Probably will do this first grow watering by hand a few times a day, I have 1 in soil a week ahead of my 3 others in rockwool as a sort of comparison. I guess I could do a grow journal if anyone is interested.

Thanks

 

[Jubilant]

I have not tried rockwool and never will probably as it is not a renewable or an eco-friend option at all. You can use Coco and reuse if you want some inert growing medium that is also affordable if you mix you own.

 

[JDMase]

Apparently commercially rockwool is reused, I had gathered I would do the same. I concur though that is a downside to the medium.

 

[Jubilant]

Apparently commercially rockwool is reused, I had gathered I would do the same. I concur though that is a downside to the medium.

It might be re-used never looked into it might very well be a viable option that is worth looking into I was more referring though to it not being a renewable resource

 

[JDMase]

It might be re-used never looked into it might very well be a viable option that is worth looking into I was more referring though to it not being a renewable resource

Yeah you're correct, although this is for a small indoor grow, where soil and coco are messy and not great yielder a.. However hydro ser ups can be big and expensive and rockwool seemed to be a good alternative. I do however have outdoor grows finishing now and will be starting organic outdoor grows, I feel like I'm balanced because of that.

 

[LandAndHeir]

Works for us 4 inch stacked on a 6 inch set on a drip tray hand watered with supernatural brand nutrients. Many many ways to utilize rockwool

 

[JDMase]

View attachment 3815701
Works for us 4 inch stacked on a 6 inch set on a drip tray hand watered with supernatural brand nutrients. Many many ways to utilize rockwool

Wow @LandAndHeir thanks for replying! Do you water 2/3 times a day? I leave mine in a tray, watered 3 times a day, occasionally overnight the tray dries up, but I'm happy with my results thus far! What sort of ph and ppms do you use? And what's your yield per plant?
I'm hoping to get maybe 2 oz per plant as this is my second grow with autos (4 dark devil, and a Dutch passion mixed bag)

 

[LandAndHeir]

We give these girls 2 sometimes 3 waterings per day, we stagger our pH and ppm according to the growth week, for example:
Vegetative state:
Clones 350 ppms @ 5.6 pH( grow only)
Small vegger 500 ppm @ 5.8 pH for about 4 weeks(grow only)
" Leach" salts before flower with 6 pH solution of leaching agent
Weeks 1,2,3 of flower 700 ppm @ 6.1 pH (bloom)
Leach salts before nutrient change again with 6.2 pH
Week 4 750-800 ppm ( half bloom half super boost)@6.2 pH
Week 5,6 750-800 ppm ( only super boost)@6.2ph
Leach salts again with 6.3 pH leaching solution
( This is where opinion comes in....you don't need to flush...because it does nothing to remove stored processed nutrients for the plant, they are a part of the plant now, however you can choose to stop feeding like we do, and let your plant eat it's remaining N from the leaves! I do personally feel like getting all salts from the root zone out helps flavor and burn but that honestly just my opinion) look up the myth of flushing and decide for yourself...you can feed til you harvest or you can do like us and learn your plants and when the appropriate time to begin taking away they're bytes to let them eat their reserves up.) - that topic can be discussed forever imo, it's all about what you like man. We save some loot not feeding the last 2 weeks and I've rarely seen this act adversely.

So week 7,8 for us is clean h2o @ 6.3 pH
Every reservoir gets 5 ml h2o2 per gallon and 1 ml sm 90 per gal
Refresh h2o2 every 3 days at same rate per gal
Water temp for us is between 17 to 20 degrees Celsius

Varieties dictate yield, but this system consistently puts out 2 lbs per light with producing cuts like Durban, blue dream , etc (9 plants per a light)
Harvest 1 light every 14 days in a 4 light room

 

[JDMase]

Thanks @LandAndHeir for that post! Awesome advice, I didn't realise that you should increase ph over time.
What strains do you grow? I'm doing auto dark Devils right now because of the YouTube guy grow pot cheaply, it's how I also found that you can grow in purely rockwool.
I'll have to look up leaching, it's basically what people refer to as flushing right? Except using a light nute mix? I think the strain hunter videos mention about flushing in that manner..
So much to learn!

 

[LandAndHeir]

Hey man I grow 26 varieties right now and pop seeds constantly, flushing is a myth my friend, il let you read about that yourself ,leaching is the term I use to describe removing salts that have built up in the rock wool by way of a mag potassium or citric acid solution flora kleen etc..I personally do this to insure my plants don't have nutrient lockouts because their uptake is being impeded by salt
My favorite varieties are my Tampa cut of crippy, Chernobyl, CCR ( my ak47 reversed onto blackberry x NYC diesel) the krinkle ( unknown landrace, possibly Pakistani or nepali, very fuely kush terps) and the blue dream make my top of the list

 

[LandAndHeir]

We gradually raise pH to get further from the peak nitrogen uptake range(5.5-6) as the plant flowers and into the phosphorus potassium range for higher uptake (6.1-6.4)

Soil ranges area bit higher so dont hold that broad interpretation as law it's just what I do in my world

 

[Dilago]

I'm currently doing a grow on rock-wool bigblocks and it is very forgiving and works like a charm.

NYCD X Ms Universe.

Much easier than growing in soil far as i'm concerned.

 

[JDMase]

I'm currently doing a grow on rock-wool bigblocks and it is very forgiving and works like a charm.

NYCD X Ms Universe.

Much easier than growing in soil far as i'm concerned.

Oh wow are those the 6" ones? I didn't know whether to go for them or not, so I went for 15L bag of the small ones and I'm going to put them in pots and see how they do.

Care to share your feeding schedule?
I'm trying to dial mine in atm so they're getting varied feeds but they aren't showing any signs of being unhappy so far!

Had a nightmare this morning, my carbon filter somehow fell off and squashed my Colorado cookies auto! I've put it in a new 3" cube and I'm hoping it recovers!

 

[Dilago]

Sure, my feeding schedule is according to the KISS principle: just Canna Vega A + B during grow and Canna Flores A + B during bloom (or Coco A + B works also like a charm). I try to keep the Ec as low as possible and wil only go above Ec 1.4 the plants seem to need it.

A bummer that your filter fell!

 

[JDMase]

Yep! I hope tell recover, it's been 6 hours and no movement though some leaves had pulled off and the stem is bent.. Fingers crossed it recovers.

Thanks for the feed schedule. I've never heard of KISS principle before?

 

[Dilago]

Keep it stupid simple.

 

[killAgreenguy]

I use rockwool and I make sure I soak in 6.0 ph water before I transplant and I actually feed drain to waiste 3 days a week and my babies look nice I make a compost tea on mon add to my feed and feed on wed feed on fri flush every change in stage of plants life so for me that's usually 3 weeks ph anywhere fro 5.7 to 6.3 depending foliar feed till week 4 or 5 (and this is for me because I have my humidity and airflow under control and flush water and yucca ph 6.3 for a week after a pre flush that's how I do my thing wit the rockwool and I get anywhere from 35g to 65g a plant dry working on som new techniques to get that more like 50-80 hopefully soon but so far so good I use 6x6x4 cubes veg for 2-3 weeks then transplant onto 36" slabs 3 per slab and flower like this

 

[JDMase]

I use rockwool and I make sure I soak in 6.0 ph water before I transplant and I actually feed drain to waiste 3 days a week and my babies look nice I make a compost tea on mon add to my feed and feed on wed feed on fri flush every change in stage of plants life so for me that's usually 3 weeks ph anywhere fro 5.7 to 6.3 depending foliar feed till week 4 or 5 (and this is for me because I have my humidity and airflow under control and flush water and yucca ph 6.3 for a week after a pre flush that's how I do my thing wit the rockwool and I get anywhere from 35g to 65g a plant dry working on som new techniques to get that more like 50-80 hopefully soon but so far so good I use 6x6x4 cubes veg for 2-3 weeks then transplant onto 36" slabs 3 per slab and flower like this

Thanks for the tips man, I'm using pony tailing in veg and then I'm bending the stems at around 50 degrees to even the canopy out as they stretch in flower.
I've had a lot of flower stretch in my rockwool babies and I'm not sure why? I'm guessing it's just a mixture of hydro and HPS light?
I've got two phenos of dark devil, one soil and 3 rockwool (should've done a side by side but ran outta soil)
Maybe I'll do a diary or something I've not kept track of these at all they just grow so much every day.

 

[JDMase]

So the two on the left are a short pheno with a weird non symmetrical leaf structure in early veg and the two on the right are tall growers. The bottom left is in soil and about a week or two ahead of the others.
I trained the rockwool ones a lot less as they stretched so much and weren't as leafy. I'm hoping I haven't made some noob mistakes and hindered them, they've had a lot of stress' due to me dialling in a new room and new method but I'm optimistic I'll get more than my last grow.

 

[killAgreenguy]

Thanks for the tips man, I'm using pony tailing in veg and then I'm bending the stems at around 50 degrees to even the canopy out as they stretch in flower.
I've had a lot of flower stretch in my rockwool babies and I'm not sure why? I'm guessing it's just a mixture of hydro and HPS light?
I've got two phenos of dark devil, one soil and 3 rockwool (should've done a side by side but ran outta soil)
Maybe I'll do a diary or something I've not kept track of these at all they just grow so much every day.[/QUOTE
I scrog and the key to mine is get the net as low as possible and when babies stretch it's arms full of beautiful buds

View attachment 3830921

So the two on the left are a short pheno with a weird non symmetrical leaf structure in early veg and the two on the right are tall growers. The bottom left is in soil and about a week or two ahead of the others.
I trained the rockwool ones a lot less as they stretched so much and weren't as leafy. I'm hoping I haven't made some noob mistakes and hindered them, they've had a lot of stress' due to me dialling in a new room and new method but I'm optimistic I'll get more than my last grow.