yup root rot! just couldn't get them to come back some of the plants where starting to grow a whole new set of root and not really use the ones they had. so i decided to start with new clones, thought it might be faster and better this way. things i have changed was water chiller a must before the plants are put in and cover the totes or buckets with some type of wrap. start of with low amount of light and as they get bigger turn more on( not hitting them with 10000 watts of light from start). A good root zone management like h2o2 , root zone (dutch master) or ucroots. next low ppm like 100 ppm wk 1 and wk 2 150 wk 3 200 IMO or as need depends on how much the uptake. 5.5 ph and let it roll up to 6.1 then drop. never drop nutz directly in too the epic center always dilute and a top of rez phd. RH between 60 and 75 a plus for veg. temps at 78 to 82. if im missing something let me know. O and a good pre veg will help
you might want to look into capulators bennies for your UC its bennificial bacteria that kills anything bad in your root zone.. I will be running it as soon as it gets here in the mail.. You basically just make an ewc tea with it and then it takes the place of your root zone conditioner (zone,CS roots, aquashield) ... an easy way to explain it is DM zone ect. kills all the bacteria in your system making it a "sterile system".. Caps beneficials are bacteria that eats all the bad bacteria and makes them so the roots can eat them and feed off of them.. Thus making your water a good bacteria playground.. There are a few growers around here using it with great success in their UC's..
I just read this thread start to finish and I know exactly what happened. My brother, you need to keep your water temps BELOW 65 degrees in a brand new system until the microbial population has a chance to sort itself out. 68-70 degrees is just too high until you have a solid colony of beneficial microbes.
Fire up round two, get your temps down, clean out the gunk in your system and flush a few times- and as counter intuitive as it may sound right now, STOP USING STERILANTS. Unless of course you'd like to be totally dependent on them until you've grown a pathogen so strong that it takes killing your own plants to get rid of it.
I have been down both branches of this road, my friend. You can spend months/years figuring it out on your own, or take my advice and be running hard with a bumper crop next run. Your call.