Help flowering plants dying

Help plants dying one by one and I don't know what to do or why I think it's root rot, temperature, humidity have been higher than ever with extra hot days lately and nothing else Ive done through veg or the other 4 weeks of flower has done this or killed them.

I'm going to get more perlite and make a new soil mix of 50-50 Pete to perlite tomorrow to transplant to anything else I can do to stop this in the future n from spreading?

If that's 4 weeks of flower...I'd start over

Water those things
Let them soak in water with a drop of dishwashing soap
You are under watered not rotting

Please don’t transplant in flower
Nothing good can come if it

That soil looks like it’s super heavy in one pic. Imo you’d do well to improve it before next run. I’d get some air to those also. In the environment you describe it won’t be long before your sick plants get mold imo

You need a better light ASAP, and honestly you really need to start over & do some research before you plant a seed.

That is a waste of resources.

RIP
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