There is one other thing you might want to look into eliminating. A virus. When you are taking cuttings are you cleaning your cutting equipment between each cutt. Is there any rust or any resin on the cutting instrument. Are you cloning in a tank were they share the same water source. Is all your equipment including anything you use to hold or transfer water or hold the plants and cutts all sterilized. There are viruses known that can cause dudding or miniture growth or pests that can get into and around the roots that can transfer viruses and cause stubby and thick unnatural root growth. There is a virus going around the usa that is know to have effected a large percentage of plants and seeds and clones that have been spread. The virus causes lower yields, bland scents and bland potency. There are other viruses and pests that can cause similar issues. With the virus in the usa its even known to have effected in some areas tap water sources. If a virus like that is the cause no mater what you do all plants will quickly get effected as its on the equipment, surfaces, pots ect. I remember when dark heart started to bring awareness to this, it was too late by the time they found out and wasnt easy to work out. Plants had already been passed out every were for some time and many producers had already produced flower for many cycles that had reached the dispensaries and private use community. Dark heart had to completely shut down there facilities and destroy everything an go into deep clean and then quarantine. Would probably be a nother thing you should look into.
