i have 2 plants, both are at the begining of their 5th week of flowering.
about two weeks ago i've noticed that in one of the plants, some of the lower fan leaves were starting to turn purple-brown, 3-4 days later it also happened with the other plant. since than, the color spread to some more leaves, but only to the lower/med sections and only to the larger leaves (not to the small ones which surround the flowreing areas).
in one plant, two of the purple-brown leaves developed large black spots (necrosis?), while all the other colored leaves appear fine if you check their buttom side (the black spotts were visible from both sides). the temperature don't drop below 60 F and is usualy above 70 F.
it seems that the discoloration has less effect on the veins of the leaves, as they are the last part to change color.
i searches a lot about this problem and did not found anything that looked similar.
disscussing this situation with a growshop salesman he adviced me to flush the plants as he think this is some sort of nut block - specificaly since i described my watering routine as one in which i water just untill the liquid start to come out beneath the pot and usualy not even that (all stays in the soil).
also, during the last days i notices the tips of the top leaves turning yellow (i guess it's a different problem)
i did not flush them yet, and would love to hear your advice - is there a problem? if so what is it? and what should i do?
pics and troubleshooting info below
What is your experience level? 2nd timer
.1) Type and wattage of lights. HPS 400w
.2) Distance from tops? about 15 inch
.3) Reflector type? cool tube set-up
.4) Is there a consistent fresh air supply? now there is, untill 3 days ago i only opened the bellows while the light was on
.5) Do you have an exhaust fan and a circulation fan? i belive it's called a bellows, the device that sucks air out, no fans
.6) What are the bulb wattages, kelvin ratings, and schedule? 400 watts, 12/12
.7) Specific brand and type of soil, (coco, peat based soilless...) and anything you've added to it. (vermiculite, perlite, worm castings...) light soil, no addings
.8) Size of container. about 1.5 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 mineral water, pH of 7.8 before adjusting
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...) test strips
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated lime, PH Up...) pH down
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule. i use bio-bizz organic plant food, like 6 differnet bottles, following the instructions - note that the bottles are 3 years old, but smells fine. at the begining i watered every 3 days and in the last couple of weeks i water every two days
14) How often are you watering between feedings, and how much per watering? isn't watering and feeding the same? i give the plants water with food inside every second day now, about 0.4 liter for each plant
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...) only the biobizz variety
16) Are your ph levels stable, or do they fluctuate? i cant tell as i can only check pH before i add the food
17) What is your ingoing water's ph? ...your runoff ph? idk
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? 2x3x7 (in feets)
21) What are the temps and humidity levels while lights are on? ...With lights off? on - 60% 73-85 F. off - 65-70 F
22) Have you seen signs of insects in the growroom? no
23) What strain are you growing? (Indica dominate or Sativa dom?) not sure, probably indica dominant
24) From seeds or clones? seeds
25) Is this an autoflower strain? i guess not