My plant is about halfway through the 4th week of flowering. Over the past week or two a problem has developed and I am not sure of the cause. It started with a few small brown spots (about the size of a pin hole) on the middle to upper leaves on the main stem. As these spots accumulated the lower leaves began to yellow between the veins (with the veins remaining green) before turning completely yellow and eventually dying (some leaves accumulated large masses of the brown dots in the middle of the leaflets, while others simply died with only a few spots). The yellowing has now progressed about 3/4 of the way up the main stem, and is beginning to work its way up the side branches. The spots are now beginning to appear on the upper leaves of the side branches as well, whereas before they were only on the main stem.
My upper leaves are curled down on the sides (like an upside-down canoe) and some have a curled claw shape. This made me think I had an over fertilization problem, but a flush last week produced no results. I also tried epsom salts at 1/2 tsp/gal at the beginning of this week, thinking it may be a magnesium deficiency (I use distilled water) but this also has proven unsuccessful.
Solid yellow leaf with brown splotches:
Yellowing between veins:
What is your experience level? first timer
.1) Type and wattage of lights. 23W CFLs x 6
.2) Distance from tops? approx. 2 inches
.3) Reflector type? Foil tape
.4) Is there a consistent fresh air supply? Yes.
.5) Do you have an exhaust fan and a circulation fan? Only exhaust
.6) What are the bulb wattages, kelvin ratings, and schedule? 23W at 12/12 (I believe they are 2700k, they are yellow, not the daylight kind)
.7) Specific brand and type of soil, (coco, peat based soilless...) and anything you've added to it. MG Potting Mix, no additives
.8) Size of container. I want to say it is about 2 gallons.
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings? No.
Your nutrients and water:
10) Source of water? (tap, bottled or filtered) What's it's ph before adjusting? Bottled distilled water, pH 6.4
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...) Drops/tube style test kit
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated lime, PH Up...) I have been mixing distilled water (6.4) to my tap water (7.5) to achieve the desired pH (~6.8)
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule. Gro-Fine Bloom (10-54-10) 1/4 tsp/gal weekly
14) How often are you watering between feedings, and how much per watering? I water 3-4 times a week, 6-8 cups at a time
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...) I use molasses at 1 tsp/gal
16) Are your ph levels stable, or do they fluctuate? Unknown, my test kit is not good for runoff
17) What is your ingoing water's ph? ...your runoff ph? Ingoing: 6.8, runoff unknown
18) Do you foliar feed? If so, with what, how often, and at what time do you spray? No.
19) Indoors or outdoors? Indoors
20) What size of closet, room or hut? Rubbermaid tub (2ft W x 1.5 ft D x 3ft H)
21) What are the temps and humidity levels while lights are on? ...With lights off? 84F on, 70F off
22) Have you seen signs of insects in the growroom? I see a stray gnat now and then.
23) What strain are you growing? (Indica dominate or Sativa dom?) I believe it is sativa dominant
24) From seeds or clones? Seeds.
25) Is this an autoflower strain? No.
Thanks a ton for any help =)