All - I'm looking for a little help identifying the issue I am experiencing. I am in week 8 of flowering and in the past 2 weeks I've been seeing my fan leaves starting to yellow then get brown spots. This is happening to the fan leaves from the bottom up. I've been looking online for the issue, but there are a few issues that might apply. Any help to narrow down my issue is greatly appreciated. I am using General Hydroponics "Flora Series Simple Recirculating" in rockwool & clay pellets. THANKS!!