Duke Skywalker
New Member
I have 6-inch Grodan blocks with FloraFlex Caps. Can I use just 1 line per plant vs. 2 per plant like I see in their videos?
Grodan Blocks
- Thread starter Duke Skywalker
- Start date
projectinfo
Well-Known Member
Two is better. One will work
Duke Skywalker
New Member
Thanks for the info!
I have the same, just started. Please can you tell me how often and for how long you are watering?
bird mcbride
Well-Known Member
I cut all mine from slab. It's less expensive. I noticed grodan is like $10 a slab. The hydro shop guy gets me a no name brand for $5 a slab, but it doesn't say which side is up, but that's not a problem for me.
I do a different style so I cut the cubes 2" x 2" x h". The 6" x 6" x h" is usually for constant flow systems.
The first time I seen this system in action I was really impressed, right up to about week seven, then the bud rot started. The roots will fill that 6" cube rather quickly. And with another guy who was using some kind of vermiculite or something with the cube his injectors kept plugging and crop failure.
If I were going to monkey with this, I'd put a timer system on the high pressure pump and give them 6-15 minute shots about 3-6 times a day with the injectors that go into the rockwool, depending on the humidity in the area where you grow. I would rip off the plastic and set them in hydro rock for drainage and root expansion.
My moms are done with drip ring but they are set as low as they can get. It runs for 1/2 hour every three days using about 2.5 gallons of spent res water for six moms, minimum. The temps are in the mid sixties Fahrenheit so they don't dry up so fast and I place a piece of reflective plastic at the base of the plant. When it comes time for taking snips I up that to everyday. When cranked up the six moms can do about 300-500 snips a week.
I only keep about an inch or so of rock under the cubes, but that's why I use tables and the trough for the moms, so the taps can stretch out instead of wound in a ball. The six inch cube is to large for a F&D table. The moms are in a trough...drain to waste.
If you want to water everyday with a nutrient solution, cut the ratio to about 1/6 of what is recommended for outside growing and aerate the solution before watering the plants with it. The moms don't need aeration because the mix is totally dissolved already. This can also be don't by shaking it in a jug well before applying.
Keep in mind that watering cycles and nutrient mix ratio vary, depending on where you live. Much like boiling an egg.
https://hydroponics.com/shop/grodan-rockwool-slabs/
I do a different style so I cut the cubes 2" x 2" x h". The 6" x 6" x h" is usually for constant flow systems.
The first time I seen this system in action I was really impressed, right up to about week seven, then the bud rot started. The roots will fill that 6" cube rather quickly. And with another guy who was using some kind of vermiculite or something with the cube his injectors kept plugging and crop failure.
If I were going to monkey with this, I'd put a timer system on the high pressure pump and give them 6-15 minute shots about 3-6 times a day with the injectors that go into the rockwool, depending on the humidity in the area where you grow. I would rip off the plastic and set them in hydro rock for drainage and root expansion.
My moms are done with drip ring but they are set as low as they can get. It runs for 1/2 hour every three days using about 2.5 gallons of spent res water for six moms, minimum. The temps are in the mid sixties Fahrenheit so they don't dry up so fast and I place a piece of reflective plastic at the base of the plant. When it comes time for taking snips I up that to everyday. When cranked up the six moms can do about 300-500 snips a week.
I only keep about an inch or so of rock under the cubes, but that's why I use tables and the trough for the moms, so the taps can stretch out instead of wound in a ball. The six inch cube is to large for a F&D table. The moms are in a trough...drain to waste.
If you want to water everyday with a nutrient solution, cut the ratio to about 1/6 of what is recommended for outside growing and aerate the solution before watering the plants with it. The moms don't need aeration because the mix is totally dissolved already. This can also be don't by shaking it in a jug well before applying.
Keep in mind that watering cycles and nutrient mix ratio vary, depending on where you live. Much like boiling an egg.
https://hydroponics.com/shop/grodan-rockwool-slabs/
since1991
Well-Known Member
This^^^. Of course it depends on you actual manifold..pump..pump height...and especially pressure (regular cheesy low flow pressure impeller type water pumps don't really have the oomph for a big manifold and even flow rates without some finagaling)
since1991
Well-Known Member
Do not remove the sleeve on any block unless transplanting to a loose medium like coco or peat mixes or clay rocks. Go to the Grodan website...they break it all down for ya. If your stacking onto bigger blocks or slabs..leave it on. Cuts down on algae. Forces roots to grow down into the new rockwool and gives less condos and apartments for fungus gnats and their larvae.
since1991
Well-Known Member
I had some ANCIENT rockwool slabs made by General Hydropnics (yes - way back they had them. At least they were wrapped in GH logos) that I whacked up recently for this. These fukin slabs were at least 20 years old too. Lol.
I'm using 40% coconut coir and 60% potting mix. Have tried the hydro before and I find that soil is pretty easy. Even just ripping out the finished ones then fishing out the root clumps. Straight in with the next and they're all happy. The wortst thing and biggest problem I find is the heat in summer. When the tent gets up to 50 deg C. It's a fight to keep the fan noise down. The power bills down and the harvest up
SuperHI TnT
Well-Known Member
You know cutting up stonewool releases those mineral fibers in the air which is not something you want to inhale...very similar to asbestos. Your body can’t expel stone fibers.
kingromano
Well-Known Member
yeah i like to spray mine with tap water when i handle them
not sure its as toxic as asbestos.. i even heard it dissolve in the organism .. so its not dangerous
not sure. if anyone can tell
kingromano
Well-Known Member
but a dust in the eye is painful as f
What about people who work in roofs all the time with batting made of the same stuff? A bit of overkill paranoia going on I think.
kingromano
Well-Known Member
yeah but its a bit different .. isolation material is glass fiber which is a bit different ..
im handling some horticultural mineral wool right now and with a good spray of water they become pretty inoffensive ..
Serverchris
Well-Known Member
No they literally make insulation out of rockwool too, most is fiberglass but just do a search on Lowe's or home Depot and you will find plenty rockwool insulation.