Root gel is not needed mate. presoak you rockwool 24hr in advance (ph issues) in a little NoShock 5ml/L and you can also add Greenfuse root as well at 1ml/L. (I also like voodoo j)
Also mist with greenfuse root and noshock.
Never 'over wet' rockwool or it will struggle to hold oxygen, less is more...think damp.
Try to take cuttings 3 weeks into mother plant's 12/12 so to monster crop from the cuttings and remember to use cube caps...essential if you dont want slime n shit.
Week 1: 1 x 100w household energy saver.
Week 2: 2/3 x 100w household energy savers.
Week 3: Big healthy thick white roots coming out the bottom of 4" rockwool with very few yellow leaves and is ready for light veg food.
Some strains can go straight to 12/12 (WW in my case) under other lighting methods or continueing 18/6 in huge E40 cfl's that has many benifits in veging and is usually highly recommended as only a few small household energy savers have served their purpose by this stage!
Very simple but very effective and works like clockwork time after time.
Some other growers may have other/quicker methods but this works for me in my northern european climate.
Happy days and happy christmas!