Rusted spots showing on a couple leaves.

  • Thread starter gomicao
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I am growing 3 Banana Bomb and 1 Cement Shoes plant in coots organic mix soil I mixed up from seed:

My soil consists of:
1/3rd Medium Perlite,
1/3 Sphagnum Peat Moss
1/6 Malibu Compost
1/6 Wiggle Worm Pure Worm Castings
Malted Barley
Crustacean Meal
Kelp Meal
Neem Cake
Karanja Cake
Oyster Shell Flour

Anyways the Banana Bomb plants are 5 weeks old, Cement Shoes 4 weeks and all in veg. Only one of the Banana Bomb is currently affected and only 2 leaves. The rest seem to be doing fine. I have 2 LED lights about 20 to 22 inches above them in a 3x3x7 grow tent, each light is 180 true watts. I keep the humidity between 57 and 60% and temps between 69F at lights off up to 78F when on. I topped them 3 days ago when they were about 12 inches tall, and when I did I mixed up my normal water and some premixed water with neem and ended up hitting them while lights were on for a few hours. The water it was in dried pretty quickly however. They were a lil droopy, but in 3 days sprung back and look really happy and much better than before and are now already nearly as tall as they were before.

I saw some gnats or fruit flies, so I started to water with some BTi solution. It looks more and more like it is fruit flies from the kitchen that made their way to my tent (red eyes/red/orange body). I have yellow sticky cards on the way to snag the 1 or 2 in the tent to ensure proper identification. I used a compost tea about a week ago. Other than that I have only been using water and molasses. I started out by using absorbic acid (vit c) to adjust my PH because it is like 8.5 out of the tap, but ended up deciding to go with the general rule that organic soil doesn't need its water to be adjusted if amended properly. I noticed these spots today on two leaves of one of my four plants...

I felt like pictures of cannabis septoria looked like the issue at first, but now I am of course confused as there could be many answers. I think I may go back to PH adjusting my water anyway with citric acid and potassium bicarbonate, just to eliminate any potential issues that could cause in regards to soil drift or nute lockout (regardless of how small a chance that may be it). I have admittingly sprayed/wet the leaves of the plants more times than I should for little to no reason and I plan to stop this, it is hard sometimes when using a sprayer to water not to mist them a little though. Anyone with any questions or thoughts? Should I remove these leaves? Leave them alone and monitor if it spreads? I s'pose I also need to bust out a loop and inspect leaves for critters too, but examining them with naked eye I have not seen anything.

PS Sorry for the blurple... I have done my best adjusting the pics/using a flash to accurately show the color of the close up of the leaves in question.


I believe lack of Calcium.

I would be pretty stoked if that is all it is! I was looking at leaf and plant diagrams, some posted here by SeaMaiden, but I was hoping that my soil and the addition of compost tea and molasses would give me an essentially water only grow. I was also planning on a top dress of the same soil amendments I used to mix it soon, and 1 or 2 times during flower. Of course I would have to wait a week or so to see things clear up from such a method. Not expecting nutrient issues already due to using 10 gallon pots.

Grow diary link here:

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