Root rot, wind burn, fungus/mold?

Hi folks,
Been having problems with last few crops, not sure what, hopefully someone will know. Plants grown in bio biz (all mix) 600w hps bio biz food ( grow ,fish mix, bloom, top max, acti Vera, and cal mag from plant magic) 9”( 21cm) oscillating fan blowing at top 9”(21cm) fan on floor of tent, tent 1.2 x 1.2 metres. Tent and pots cleaned between every crop with Dettol ( household antiseptic)
Leaves curl inwards along length of leaf (serrated edge) to underside of leaf have red tinge and are at first limp then crispy. Affects top mainly 50% of plant leaves and both new and old leaves( small & large) Plant stops drinking water and loses smell. Happens overnight.
Have taken plant out of pot (10 litre) to smell soil for root rot doesn’t smell rotting but doesn’t have many roots. The first 2 times happened plants were on 5 th week flowering 3rd and 4 th 7 week flowering this time 3rd week flowering. Look forward to hearing anybody’s thoughts or have experienced this, thanks for reading have put pictures on but not sure if they have uploaded. Happy new year

Could be a lot of things to be honest. Overfertilization, overwatering, too much direct fan air (wind burn), high temps on the plants
can cause problems. Humidity (high or low) and pH issues can also wreck havoc on things. There's also soil pests that can cause
issues. You should make a list and start ruling them out.

It may have all started with overwatering.

You mentioned not too many roots. That should be something to research ASAP.

Start your root research with this link and good luck:

https://www.alchimiaweb.com/blogen/cannabis-roots/

Hey troutman thanks for the reply, I agree it could be a number of things. I can’t decide if it’s wind burn, root problem ( good link you sent), fungus. Ruled out the other possible problems.
over fertilised- use slightly less than bio biz grow schedule, flush every Sunday.
Overwatered- water when pot is light, top dry, usually 1 litre per day , flush 1 1/4 litre.
High temp- 28-30 cent
Humidity- 40 - 60%
Ph- don’t know but use garden lime
Wind burn- got new oscillating fans 2 crops ago but had problem before with older fans which weren’t strong. But the closest picture I have seen on internet is of a plant with wind burn. Have also read that usually only thing that makes leaves turn under is wind burn so not sure on this one.
Roots- yes roots aren’t well developed and aren’t exactly white have read link and ordered rhizotonic and trichoderma.
Fungus - plant loses smell I’ve read fungus can have this effect , has a green(?) smell. No obvious signs of gnats or anything on top of soil.
I’ve cut half of it down bottom half wasn’t affected really so left it to see if trichoderma has any effect.
Will let you know if it does.
Thanks