Hi CG and everyone
I'll start by saying I found this thread while googling some random issue, and found it to be so good, I've just registered for the forum and this is my first post here.
My question for you is regarding your 4" cube onto the 6" cube. I have recently begun using exactly this setup as my new designated grower status in Canada allows me 25 plants (previously I've been using flood and drain tables with 4" rockwool cubes and lots o' plants).
I have found that when I placed my 4" cube onto the Hugo block, within about 1 minute or so the 4" cube has enough water sucked out of it that it feels as though "it is so lightweight you could pick up the whole plant and block with a leaf blade without breaking it."
In my system (did you guess that I have a recirculating system), the solution is simple...I just run the drippers on 15 minutes every hour until the roots have a chance to take hold in the bottom block. The one plant I had on the side ( my system is built for 24 so I had a 25th one I was hand watering daily) was so dry, and the top of the hugo block too, that the plant got stunted and the roots never descended into the Hugo until I sliced it in half (the hugo that is) and placed a plastic bag in between the two layers. Finally this allowed the top cube to retain enough moisture to allow the plant to come back and then once the top half of the hugo was rootbound I removed the plastic bag and she was ok after that.
So my question is have you encountered this phenomenon and what is your 4" onto Hugo transplant procedure if you have one.
Thanks and much respect
The Recirculator
Happy Happy
This is common with rockwool. First off, soak the Hugo Blocks overnight prior to use. This will increase their holding capacity...the more water they hold, the less will be sucked from the 4" block. This should solve your current problem. I experienced the same thing when in a hurry and skipping the block soak step.
Make sure the root coming from the 4" block are not holding the block slightly off contactg with the 6" block.
After placing the 4 on the 6, water just the 6 for the first couple waterings. The idea is to tease the roots into the 6" block.
Last, and absolutely the most important, let the block dry out between waterings. Rockwool holds an assload of water, yet water is fully available to plant right to the last drop in the block. If you have experienced a block dried out enough to cause wilting, you'll know how feather light that block needs to get before wilting. When the rockwool is allowed to dry out between waterings, a large root structure will develope. Also, I've found that growth is fastest when the blocks are between 50% wet and dry enough to almost wilt.
Try placing the rockwool Hugo Block into a 2 gallon pot with some Hydrotons in the bottom. For larger plants I fill the pots half full with a rockwool crouton/perlite mix. It's important to only add rockwool croutons to a pot that will be holding a plant s
o big the block cannot hold 24hrs of water. Otherwise, the block will stay too wet and the roots will not bite into the pot medium.
Rockwool can be a bitch. That's why it's not a good medium for noobs. But, once you make friends with it, it can be a very productive and easy medium to use.