Rockwool/dripper problem for a new setup

Treehausdc

New Member
I recently changed a small 8 light 32 plant system from coco coir with micro drippers, over to a Rockwool system(same drippers pump and setup)
However i can’t seem to get the top cubes wet at all.
the plants vegged into 6X6 cubes and then sat atop 8X8 cubes (i now know this is probably overkill, but next time I’ll not use the 8X8 and just keep them in the 6X6) the plants have begun rooting into the bottom cubes but are not able to reach the moisture at the bottom.
i run my pump for a total of 4 runs .25 gal each time. It was the same time as from when I had my coco coir in 5g buckets, so I figured I would start there and dial it down as the cycle continued and I saw how much was runoff. And see how much they dried out over night.
the first night passes. All the cubes are bone dry and the plants STRESSED. The top cubes are not even marginally moist and the bottoms are dry halfway up and moist to wet on the bottom.My runoff tank is fed by a little giant pump and it showed 22 gallons in one day.
so almost all the water being supplied to the cubes is draining straight through and into the drains and into the runoff pump. I have no idea why this would happen, but it’s clearly user error and inexperience with rockwool.
i thought to shorten the cycle and break it down into 8 cycles instead of 4
With a much shorter dryout period over night. But it ended the same. I’ve resorted to hand feeding twice a day until I figure out what stupid mistake I am making.
 

budman111

Well-Known Member
I recently changed a small 8 light 32 plant system from coco coir with micro drippers, over to a Rockwool system(same drippers pump and setup)
However i can’t seem to get the top cubes wet at all.
I do NFT and you don't want to top of the cubes wet, just damp and I even use Cube caps to keep them moist and no more
 

Tolerance Break

Well-Known Member
They have 0 moisture though and the plants are dying / wilted completely. That’s the problem
Keep watering by hand until you have a healthy amount of roots coming out of the bottom of the large cube. Then go back to your system. If the problem starts up again, increase the amount of water per run. Just my two cents.
 

Treehausdc

New Member
I get that, but I’m currently running a gallon of water per day into a 6X6 cube I feel there has to be a problem if it’s not any bit wet, like it weighs as much as a feather. Why wouldn’t any moisture stay in the top. It doesn’t make any sense. Does Rockwool use more than coco coir, water wise ? I’ve used this setup for lots and lots of runs before and had no problems. And no the drippers are not clogged the runoff tanks are filing fine and I watch them drip.
 

Tolerance Break

Well-Known Member
just dip them in water for about 4-5 seconds a day every few days as they hold a lot of water, always water from underneath rockwool and never from the top.

I use this method to air root prune seedlings on a wire mesh
I water from the top in veg, but I intentionally keep my plants pretty small. Whats wrong with top feeding?

It sounds like youre telling him to just toss his top feed set up if he is going to run rockwool
 

budman111

Well-Known Member
I water from the top in veg, but I intentionally keep my plants pretty small. Whats wrong with top feeding?

It sounds like youre telling him to just toss his top feed set up if he is going to run rockwool
Top feeding promotes fungi and pathogens that we dont want, use cube caps and keep them moist only and I'm not telling OP to do anything, maybe using it more purposefully is better is my penny's worth. GL.
 

Treehausdc

New Member
Top feeding promotes fungi and pathogens that we dont want, use cube caps and keep them moist only and I'm not telling OP to do anything, maybe using it more purposefully is better is my penny's worth. GL.
It’s not really top feeding but I hear what you’re saying. My question is for people who have stacked Rockwool in the past and may know a way to maintain some moisture in the tops prior to them rooting through the bottom blocks. The drippers are pushed slightly below the surface. Dipping them into water is out of the question. Imagine taking 30 pretty large plants out of trellis to dip them into water on a near daily basis
 

Tolerance Break

Well-Known Member
Top feeding promotes fungi and pathogens that we dont want, use cube caps and keep them moist only and I'm not telling OP to do anything, maybe using it more purposefully is better is my penny's worth. GL.
I believe you, but I have never heard this before. Care to give me directions as to where I can learn more about it?
 

budman111

Well-Known Member
I believe you, but I have never heard this before. Care to give me directions as to where I can learn more about it?



Advantages of air-pruning:
· promotes branched root systems
· encourages new roots to sprout
· prevents roots from spiraling
· prevents plants from becoming pot-bound
· plants may remain in pots, plugs or plant bands longer


LINK TO STUDY:
 

PLEDGEY

Member
It could be the cube at the bottom, the 8x8, is drawing out the moisture from the 6x6. I notice this when I presoak cubes myself. Stand them on top of each other to drain and the ones at the top are bone dry and weightless in no time while the ones at the bottom, eventually, drain nicely. Get 2 cubes and soak them with water. Stand the 6 on top the 8 and see if it drains it as dry......just a thought.
 

Star Dog

Well-Known Member
I've never grown anything other than seedlings and clones in rock wool...but ime when you sit one rock wool cube on top of another the bottom cube drains the top cube rapidly?

If you have some spare try it you will notice the bottom cube draining the top one immediately.
 

PizzaBob

Active Member
Started growing in rockwool 30 years ago. RW tends to hydrophobic if dry and needs be sufficiently wetted to be properly irrigated. I’m suspecting you let the cube dry out. Once that happens top irrigation will not absorb. If you are not getting any runoff even between the wrap and cube you just need to keep the pump going longer.
What is your cycle on time and intervals? Are you using a cycle timer or just a digital timer? Please give settings.
 
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