I think I might suddenly have a problem

[Alpaca]

I looked in my tent today to find this (brown parts are soft not dry):

I've been going light on the feeding, giving just 0.5 ml/l of green sensation last feed (0-9-10) in 7 liters. Mainly because I've been having some orange rust spots that I thought was calcium lockout at first

The browning is only happening on older growth, am I more likely over or underfeeding right now? My soil pH is around 6.5 and I'm in week 7 of flower. I wish I had a ppm meter but I don't yet

 

[Alpaca]

I'm a dumbass, the browning near the vent is probably from me testing out a heater blowing into the vent 3 days prior, which turned out to be too powerful after testing for 3 mins. The heat stress probably induced this on that part

 

[Dirtbag]

I'm a dumbass, the browning near the vent is probably from me testing out a heater blowing into the vent 3 days prior, which turned out to be too powerful after testing for 3 mins. The heat stress probably induced this on that part

That will do it. I was gonna say it looks abiotic.

 

[Alpaca]

Am I right in thinking the orange rusty spots call for less feed? its definitely not the fungus and I checked pH for calc lockout

 

[mysticepipedon]

I'm a dumbass, the browning near the vent is probably from me testing out a heater blowing into the vent 3 days prior, which turned out to be too powerful after testing for 3 mins. The heat stress probably induced this on that part

I was about to ask if you had tested out a heater, 3 days prior. I amaze myself sometimes.