my process with rockwool.
Clone domed tray, I cut apart the plug insert tray into groups of 3x3 to make it much easier to clean and check roots without having to lift the full tray up. I put 4 rockwool plugs into the 4 corners of each plug tray Ive cut apart. The plugs are put into 5.6 ph water with no nutes if seedling, if clone than 200ppm of calmg and maybe a splash of 055 nutes, maybe superthrive too. Those are than domed for 10-14 days before I can transfer them into DM6.5 cubes. Those cubes I use 200ppm calmg maybe superthrive, sometimes ill put great white into the bottom of the hole of the cube where the plug inserts into. When I soak it, i do not fully soak them, i hold it into the nute water until the water goes about halfway up the hole. I than shake out all excess water, same with plugs initially, usually takes about 2 mins of shaking. They tend to weigh about 7.5 ounces. I than move the plug into the rockwool and keep it domed up for 4 to 10 days - it takes on the longer side if I use great white for roots to pop through the bottom of the DM6.5 cube. Once there are adequate roots showing at the bottom of the cube, they than get put into a 4" net pot I believe, only pushed into it about halfway, i rub the side of the pot with my finger to break off any excess rockwool, than it gets put into a dwc bin, making sure the water is about 2 or 3" away from the bottom of the net pot. For the next 72 hours I lift the net pot off the dwc bin to check its moisture content, ideally I want it to become more dry or staying the same saturation as when it started, If it becomes heavier, instantly i must remove some water and lower it down some more. Once you get roots into the water with your air stones at that point you can raise it to about 2" away, once the plant is over 12" tall than I can have the water level about 1.5" away from the base of net pot as there are more roots to block the splashing up to not over saturate the cube. The main prob this guy is having is those cubes ARE SOAKED... that is a big NO NO in rockwool. Now the only time I see root rot, is when pieces of the rockwool have falling down from the net pot into my water bin and parts get stuck on the roots which if not maintained will cause rot. Only way I can think to fully prevent that is use smaller rockwool cubes, or larger net pots and fill the bottom 1-2" with hydroton to help block anything from falling down into the water - and if that is the case ideally my water level would be 1-2" higher than prior to make up that vertical difference. current water temp for me is 67-70 in summer it can get around 74 but ive rarely noticed a difference in root rot between summer or winter times.