'...15 babies in my ebb and flow system ... 4" rockwool cubes .. so will i have to transplant the rockwool into hydroflora containers or anything or do i keep them in the rockwool? and one more thing since rockwool holds a alot of water how long should i flood twice a day 15 minutes ya think?
What system do you have?
You could get away with using Cori Board to cover the tray tops and just standing your cubes in the tray where the holes are cut in the Cori Board.
How big are your 15 babies?
Do you reckon they will be huge? Answering that question will determine whether or not additional support might be required to hold your plants upright over the course of time.
Personally I would have put my small 1" cubes into 14cm net pots and then put my net pots onto my flood & drain system.
If you aerate your reservoir then you can flood for longer periods than if you do not aerate your reservoir. The idea is not to drown your roots, but oxygenating the reservoir content will make this less likely and you can therefore flood 5-15 times per day for any time scale, but avoiding the roots are not too long without moisture.
When I worked with flood & drain I flooded for most of the day and occasionally drained. I had an aerated reservoir and an air line running beneath every net pot. I could run this system for 24hours daily without harming the plants in the way of cubes being too wet etc.
