Flood and drain rockwool

ToFarGone

Well-Known Member
So I have some rooted clones I threw into some 6” rockwool cubes and I’ve been wondering about watering schedules. I am going to do flood and drain. My res has a chiller and stays at 69 and I have a recirc pump with a water flow to keep the nutes and oxygen moving.

However it Seems as though there are 2 trains of thought on watering and I’m wondering what people have done in the past

1 says to flood the cube then wait potentially 4-5 until the cube has really dried up

The 2nd says flood 3 times a day and treat the rockwool like a hydroponics system in that every time you flood you push new oxygenated nute solution into the cube.

They have been in the 6” cubes 2 days now with only 1 flood so far.
 

PJ Diaz

Well-Known Member
So I have some rooted clones I threw into some 6” rockwool cubes and I’ve been wondering about watering schedules. I am going to do flood and drain. My res has a chiller and stays at 69 and I have a recirc pump with a water flow to keep the nutes and oxygen moving.

However it Seems as though there are 2 trains of thought on watering and I’m wondering what people have done in the past

1 says to flood the cube then wait potentially 4-5 until the cube has really dried up

The 2nd says flood 3 times a day and treat the rockwool like a hydroponics system in that every time you flood you push new oxygenated nute solution into the cube.

They have been in the 6” cubes 2 days now with only 1 flood so far.
As far as option 1, "wait potentially 4-5" what's, days? No no, that's crazy talk.

Regarding option 2, rockwool IS a hydroponic medium, so I'm not understanding the disparity.
 

ToFarGone

Well-Known Member
As far as option 1, "wait potentially 4-5" what's, days? No no, that's crazy talk.

Regarding option 2, rockwool IS a hydroponic medium, so I'm not understanding the disparity.
There are posts saying at first in veg to get roots to spread they will go 4-5 days between floods to let it dry out

For option 2 I meant hydroponic in that Dwc or nft the roots are constantly submerged. So people flood 3 times a day in theory exchanging the water pushing in new oxygenated/ nutes.

Just looking to see what others are doing to get the roots to push through the cubes before flowering them
 

RangiSTaxi

Well-Known Member
Use Hydroton. Rockwool is only ok for a gully systems where the water flows 2 mm from the bottom and the rock wool sucks up from the bottom think lettuce short harvest plants or possibly drip feed, think tomatos, but both have nutrient salt build up issues.

Rock wool holds too much water and not enough air, rock wool too many nutrient salts which it doesn't let go of build up over time, Use Hydroton , clay balls and save yourself a headache.

cannabis doesnt like wet feet or lack of oxygen, better off with hydroton, pumice or possibly perlite. hydroton being the less likely to block pumps or filters of the 3.

Its some what possible to get through veg with flood and drain rockwool but to get to the end of flower is another thing.

In every case , hydroton will out perform, in fact its fairly bullet proof compared to rock wool.

I see the attraction of rock wool , if it worked id be doing it.

but no. it doesn't work

I recommend Potting Mix to all newbies preferably indoors growing as growing outdoors is a headache in itself, and forget hydroponics till they have grow for more than 5 years in soil or potting mix.

I use to do flood and drain hydroton, it was awesome, but im doing potting mix now after 20 years growing, and what I grow is still awesome.

I do agree with your first post toofargone if your had to "try" make it work those are both good options.

If you want to have a go at it, its all good yearning and I love to be proven wrong.

It can be done, Ive done it myself. But i dont recommend it. keep us posted.
 
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Florere

Well-Known Member
It’s very doable with Mapito/rfx and I know also dudes who do it with cubes.
Look at this topic. It’s dutch but just look at the pictures. It’s from 2009


And this topic with a movie from even before that

 

Therrion

Well-Known Member
I've never had problems with Rockwool. Top feed is the best method because it washes off salt build up. Rockwool also has one of the best water to air ratios. If you are having drainage issue then try Pargro quick drain. What is your grow room temps?
 
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Renfro

Well-Known Member
A lot of people don't have problems with rockwool. I never had good luck with it. I had much better luck with hydroton or nothing, just use net pots, put a cover on the tray, drill holes for the net pots to sit in and walla. Maybe toss a coco mat in the bottom of the tray.
 

2com

Well-Known Member
Rock wool is a medium with lots of issues. It doesn't dry out quickly at all. And if you're going to do flood and drain,your cubes better be PACKED FULL of roots and THEN SOME to have success.
This isn't really true, and then the second point is basically true of most/all mediums. If you treat coco like everyone tells you, but you have a small, non-established root mass, it'll stay soaked for too long. It's the same with RW.
 

2com

Well-Known Member
Use Hydroton. Rockwool is only ok for a gully systems where the water flows 2 mm from the bottom and the rock wool sucks up from the bottom think lettuce short harvest plants or possibly drip feed, think tomatos, but both have nutrient salt build up issues.

Rock wool holds too much water and not enough air, rock wool too many nutrient salts which it doesn't let go of build up over time, Use Hydroton , clay balls and save yourself a headache.

cannabis doesnt like wet feet or lack of oxygen, better off with hydroton, pumice or possibly perlite. hydroton being the less likely to block pumps or filters of the 3.

Its some what possible to get through veg with flood and drain rockwool but to get to the end of flower is another thing.

In every case , hydroton will out perform, in fact its fairly bullet proof compared to rock wool.

I see the attraction of rock wool , if it worked id be doing it.

but no. it doesn't work

I recommend Potting Mix to all newbies preferably indoors growing as growing outdoors is a headache in itself, and forget hydroponics till they have grow for more than 5 years in soil or potting mix.

I use to do flood and drain hydroton, it was awesome, but im doing potting mix now after 20 years growing, and what I grow is still awesome.

I do agree with your first post toofargone if your had to "try" make it work those are both good options.

If you want to have a go at it, its all good yearning and I love to be proven wrong.

It can be done, Ive done it myself. But i dont recommend it. keep us posted.
So you're saying RW is only good for top fed, or bottom fed...?
 

2com

Well-Known Member
There are posts saying at first in veg to get roots to spread they will go 4-5 days between floods to let it dry out

For option 2 I meant hydroponic in that Dwc or nft the roots are constantly submerged. So people flood 3 times a day in theory exchanging the water pushing in new oxygenated/ nutes.

Just looking to see what others are doing to get the roots to push through the cubes before flowering them
No, you're on the right track. 4 or 5 days sounds pretty crazy. What I've learned is that the plant's roots benefit from a period of less saturation (dryer than when irrigated) no matter what medium, really. There is a perfect point of "drying out" that you should wait for while the plants are getting established in a container.

For example, you have a rooted clone in a rapid rooter, you let it fully root. You move it to a party cup, you water it once and wait until it is significantly less wet (24 at least on the first day for sure). You keep doing this until you have to water once a day (maybe a couple few/days). Then, if you haven't transplanted already due to height/timing/whatever, you'll notice you have to water more than once a day. At this point you could up the waterings to multiple a day, or move to a bigger container. With these hydro style mediums you can stay in the smaller container and increase waterings without much/any drawback for quite a while, requiring smaller containers and less medium.

Here you go: https://www.dudegrows.com/?s=capn+style
There's a 5 or 6 (or 7) part series on his style. It absolutely kills it, trees or not.
Hopefully some of that helps.
(edit: for clarity)
 
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