problems

so this is my first grow, everything was going good transplanted some clones i got and they were looking good but this past wekend it was super dry and i have a grow box out side in a shed so iot was pretty dry in there now my 5 white widow plants have yellow spots and some leaves are dying...

I have a problem and i'm hoping you can help. I have been growing my plant indoors since 4th October and i've just noticed these marks appearing on my plant someone mentioned phosphorous defiecency. Please a second, third and fourth opinion. The leaves are twisting a bit and as you can see from...