leaves have" rust specks" on them

some of the big fan leaves just dropped dead in two days. sporatically through the entire plant. doesnt look like normal nutrient burn. they completely burned up into a rusty brown. they also have rust specks burning through some of the other leaves. fourth week of flowering in soil.

I had a similar problem. I bet your PH level is TOO LOW when you water them. You want it to be about 6.5.

I have had a similar problem and recently checked my ph. I use Alaska Fish fertilizer and it sinks your ph. with the nute combo I'm using it drops to around 5.5. Not good for soil. Any suggestions for a cheap ph up?

my problem might be co2 burn. I put a homemade yeast and sugar bottle under the plant and the circulating fan accidently got switched off during the dark period

where do you get stuff to test the ph? I will do that also. thank you guys for the help

I heard coffee grounds up your ph. sounds right cause I know coffee gets acidic after it sits for a day

It is not the yeast generator causing this problem. Your pH is off and the micro nutrients are being locked out, causing the spots on the leaf. Correct your pH and the problems will go away. The damaged leaf will not recover, but the plant should grow unaffected leaves when this is resolved.

PW

so i got test strips. the total alkalinity is over 180. ph is 8.4 I have no idea what that means! pretty hard water too.