Rockwool cubes

High all DUGOUT here, I have a simple question to ask. When ordering my unit I also ordered 1" and 4" rockwool blocks and at the co. I purchased my unit from said the 4" rockwool blocks might hold to much water for the plants. I have a drip unit and was wondering if anyone had any info on this. Will they be over watered with these blocks or should I just use the 1" block. Thanks for any info you can give me. Burn one for me the old hippy dugout

go with the 1in.

I used 4" cubes on my first grow, and I found they held too much water and I was getting some ram's horning....my next grow, I switched to 3" cubes placed in a pot half full of hydroton, then the rockwool, then more hydroton, and I have not had any issues since doing so. I grow using ebb&flow, feeding 3xdaily for 15 mins.

Dugout said:

High all DUGOUT here, I have a simple question to ask. When ordering my unit I also ordered 1" and 4" rockwool blocks and at the co. I purchased my unit from said the 4" rockwool blocks might hold to much water for the plants. I have a drip unit and was wondering if anyone had any info on this. Will they be over watered with these blocks or should I just use the 1" block.

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You got some good advice- 4" cubes are not the best for cloning because they hold far too much water for clones. Ideally, you're looking to have about 50% of the water weight used by the plant or evaporated in 24h in rockwool. RW is highly absorbent and easy to overwater. See this guide on cloning in RW cubes for detail.

1" cubes are a bit small for cloning. They tend to dry out quickly and need dampening 3-4x/day when on a heat mat. The water stored in plastic wrapped 40mm (~1.5") cubes will get a clone which has not yet set root through 24hrs. Once they have roots, water uptake goes up sharply and they need watered every 12hrs.

You can use the 4" cubes as your main growing media but they are not generally compatible with drip watering. They're also too small for the size and water uptake requirements of advanced plants.

Drip feeding works best with low/er absorbency media like clay pellets. Low absorbency media permits frequent if not constant drip feeding. If small plants in pots of RW floc or RW slabs/large cubes were drip fed any more than 1x/day, overwatering is the likely result. Drip systems have a serious Achilles' heel- the drippers will clog with nute salts unless cleaned every other day with a toothbrush and plain water.



Tray-type flood systems are much simpler and require almost no maintenance.

I ran 175mm x 175mm pots RW floc in my flood systems for years, worked OK. I flooded that material 1x/day at lights-on.



I've switched to stuffing pots with Fytocell as it has a higher air content than floc and permits more frequent flooding- it's nearly impossible to overwater. I still tightly pack about 25-50mm of floc in the bottom of each pot to keep the Fytocell from coming out of the drain holes. Fytocell also floats- the wet layer of floc weights down the pots enough that they don't float. If you can't find Fytocell, try perlite instead. Behaves similarly. I flood Fytocell 2x/day for plants in flowering wks 1-2 and 3x/day for larger, more mature plants.

platypusmann's using pellets in a flood system, good for frequently introducing oxygenated nute soln to the roots, improving vigor and speed. When he puts his clones in RW in the pellets, he'll be keeping his RW above the flood level as he knows that frequent flooding of RW will cause overwatering symptoms. He's keeping his pellets wet and counting on the roots out of the bottoms of his RW cubes to seek down into them in the first week or so. RW cubes should be about 1/2" above the flood line. Once roots are down into the pellets, they can be flooded really quite frequently, starting with 5x/lights on and even more often for vigorously growing, more mature plants.

Al is dead on....my RW is 1/2 to 3/4 inches above the flood line...I use it as much as a stabilizer as a medium......Al you are good to be aware of exactly what I am doing....mad props!!!

Thanks, ppm.

I knew you knew what you know or you'd be having troubles, which you're obviously not.

PPM....I love it...never thought of that...LOVE IT!!!!

heh, there's the stoned slacker coming out in me... can't even be bothered to type out someone's full username, how lazy am I? Glad my abbreviation was one you like, anyway. We aim to please.

High all, DUGOUT here. Thanks for all the good info. I really appreciate all of the quick reply's they helped a lot. Unfortunately I am new to this and don't understand a lot of the terminology some of you use. Al B. Fuct I appreciate the good info but a lot of the terms you use I don't understand and I suck at metrics just a metrics challenged American so I have to use this computer to convert. I am stuck with this drip system for a while because I am disabled and on a very fixed income. I use marijuana for pain due to I will not take narcotics due to my past and Marijuana seems to help just as well as that crap. I had never heard of the cleaning holes with water and toothbrush. I have ruined the one female I had from my so so seeds. I transplanted from bucket to My hydro unit and I screwed it up. I no longer have any smell to my plant and the upper buds the hairs are turning dark like they are burning up. I am watering for 45 min. every 3 hours is this to much? I have my light about 6 inches from the top of the plant. So do you think it is a waste of time to continue this plant or start over I know were most of my mistakes have been made. I am lucky when it comes to germination since I only grow 2 or 3 plants at a time I can take my 1" rockwool cube after the seed has has sprouted and put in cubes and set the cubes in a lipped pan with about 1/2 inche of water in the bottom cover with plastic and due to the warmth this time of year and set them outside to get started this seemed to work really well and then transplant the 1" cube int the clay pellets. I trasplant when they are between 4 and 6 inches tall. I know I have rambled on and I apologize so have a great weekend and burn one for me. The old hippy DUGOUT

Dugout said:

I suck at metrics just a metrics challenged American so I have to use this computer to convert.

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Tried Google Calculator? It does some amazing shit, not just simple maths, not just metric-imperial conversions, either. You can convert litres/100km into mpg, ml/L into oz/gallon, etc. Ever wondered how many smoots in a furlong? Wonder no more.

I had never heard of the cleaning holes with water and toothbrush.

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oh yeah.... a very necessary maintenance job with drips.

I am watering for 45 min. every 3 hours is this to much?

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Yes, and for almost all situations. What medium are you using?

I have my light about 6 inches from the top of the plant.

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Too close for just about anything but a 400HPS in a cooltube.

So do you think it is a waste of time to continue this plant or start over I know were most of my mistakes have been made.

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Got pix?

It's probably time to start over, but I'd like a look at this plant if I can get one.

I am lucky when it comes to germination since I only grow 2 or 3 plants at a time I can take my 1" rockwool cube after the seed has has sprouted and put in cubes and set the cubes in a lipped pan with about 1/2 inche of water in the bottom cover

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Hugely lucky. Surprised this isn't killing them outright. RW must not ever be allowed to sit in a puddle of water, nor be watered frequently or for long periods. It is highly absorbent and saturates in seconds. This drives all the air out of the material, necessary for root formation. RW must be kept damp, never wet or saturated. If you have slow development of seedlings in RW cubes which are kept in a puddle of water, you now know why.

Because of its high absorbency, RW is generally incompatible with drip systems, unless the drip feed runs for only a few minutes, 1x/day. Handwater seedlings or clones in RW cubes by dipping a corner of the cube in pH adjusted water (5.8 ). It's the best way of gauging how much water they are allowed to soak up.

Once you have roots out of the cube bottoms, the cubes can be put in pots of pellets. The drip system should then be organised to water the pellets only, never the RW cube. Drip rings are well suited for this purpose.

Hey Al, you're saying no drip feed from top of the unit down on top of RW cube?? I just made a system with the feed tubes running over the top of cup, although I haven't put into operation yet, should I change it to bring feeding tubes up underneath into the cups of hydroton? Sorry, don't mean to hi-jack this thread.

Al B. Fuct said:

Tried Google Calculator? It does some amazing shit, not just simple maths, not just metric-imperial conversions, either. You can convert litres/100km into mpg, ml/L into oz/gallon, etc. Ever wondered how many smoots in a furlong? Wonder no more.

oh yeah.... a very necessary maintenance job with drips.

Yes, and for almost all situations. What medium are you using?

Too close for just about anything but a 400HPS in a cooltube.

Got pix?

It's probably time to start over, but I'd like a look at this plant if I can get one.
Hugely lucky. Surprised this isn't killing them outright. RW must not ever be allowed to sit in a puddle of water, nor be watered frequently or for long periods. It is highly absorbent and saturates in seconds. This drives all the air out of the material, necessary for root formation. RW must be kept damp, never wet or saturated. If you have slow development of seedlings in RW cubes which are kept in a puddle of water, you now know why.

Because of its high absorbency, RW is generally incompatible with drip systems, unless the drip feed runs for only a few minutes, 1x/day. Handwater seedlings or clones in RW cubes by dipping a corner of the cube in pH adjusted water (5.8 ). It's the best way of gauging how much water they are allowed to soak up.

Once you have roots out of the cube bottoms, the cubes can be put in pots of pellets. The drip system should then be organised to water the pellets only, never the RW cube. Drip rings are well suited for this purpose.

Click to expand...

Space Angel said:

Hey Al, you're saying no drip feed from top of the unit down on top of RW cube?? I just made a system with the feed tubes running over the top of cup, although I haven't put into operation yet, should I change it to bring feeding tubes up underneath into the cups of hydroton?

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Don't drip feed the cube. Use a drip ring to water the pellets only.

Al B. Fuct said:

Don't drip feed the cube. Use a drip ring to water the pellets only.

Click to expand...

Thanks Al, will do! PS... I love your user name. has alot of character!

High all Dugout here, Thanks for all of the info. I only have rockwool 1" cubes and 4" cubes so what other medium might I be able to use instead of rockwool that I can find at like Walmart any info would be greatly appreciated. O yea so you don't have to look back I have a small drip unit that is about the size of a square 5 gal bucket. I don't want to screw up the start this time. Burn one for me the old Hippy DUGOUT

Space Angel said:

Thanks Al, will do! PS... I love your user name. has alot of character!

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Wait'll you meet my Uncle Butt and Aunt Tittie.

Dugout said:

High all Dugout here, Thanks for all of the info. I only have rockwool 1" cubes and 4" cubes so what other medium might I be able to use instead of rockwool

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You won't want to drip feed RW *anything*, not cubes, not RW floc. Like the other poster, you will want some clay pellets if you want to drip feed, using a drip ring, so the pellets around the cube are drip fed but not the cube itself.

Can't get pellets? Try perlite. Should be in the gardening area at Wally World.

Make a drip ring out of a T fitting and a length of the tubing that connects to your pump.

howdy al
pardon me for barging in, could you tell me if it makes any difference if the clones are cut and grown from 5.5mm, or if they are grown to that thickness in veg in the aero sytem and then flowered from smaller cuttings. the point being would they still produce 1 oz per clone either way. cut and flowered at 5.5, or grown from smaller clones to 5.5 and then flowered. up until now before reading this i was having a hell of a time getting 1oz per clone, got a few but not many, apparently the thickness of the stem is critical to reach that goal. would that also mean an even thicker stem could produce even more, say 1.5oz or 2
thanks obg

I can't speak to the yield difference between clones which started life with a nice thick stem as opposed to those taken from very thin branches- I can say that thicker stemmed clones root more quickly & vigorously.

thanks al

so basically you have found that stems over the magical 5.5mm threshold perform best, i am going to have to ramp up production to provide 96 of these babies very frequently.thank you again for your help

obg

I arrived at the 5.5mm figure by doing a few batches of clones with thicker and thinner stems and compared the results. All looked a bit like this:



The stack on the left all have stems of about 4mm or less. The stack on the right all are over 5.5mm.

Please see: https://www.rollitup.org/hydroponics-aeroponics/15030-batch-clones-rockwool.html

oldbongwater said:

i am going to have to ramp up production to provide 96 of these babies very frequently.thank you again for your help

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no worries.

You might consider doing only enough clones to fill 1/4 of your flowering area every 2 weeks. If your flowering area holds 96, you need 24 cuttings every 2 weeks. This way, you get 24 plants out to harvest every 2 weeks. Cuts the manicuring workload to manageable levels and allows you to clear space for the next batch in a reasonable amt of time. If your whole flowering area is ready for harvest at once, consider that it is going to take quite some time to manicure those plants to clear space for the next mob to go in.