Need help with diagnosis

Hi all,

First time grower here. I'm having some trouble with a few of my babies. I've had a few deaths in the family already and it looks like one of our friends is on their way out. I was wondering if there was anything I could do. I also have some spotted browning on the lower leaves on some others that seem potentially problematic.

I'd like to thank each and every one of you in advance for your support and understanding during this trying time.