I am about 2.5 weeks into veg with these six plants. Back row are Strawberry Cough sativa and front row are Deep Line Alchemy indica. My tallest indica plant in the middle has some spotting on two of the large fan leaves towards the middle of the plant. First noticed the spots about 5 days ago and I have treated all plants with a fungicide neem oil spray three times now. I haven’t noticed the spread to any other foliage yet, but I would like to nip this in the bud if it is in fact a fungus. I am thinking possibly septoria cannabis, but I haven’t noticed it getting any worse and no real necrosis to speak of. My second thought is that it could be some sort of nutrient deficiency, but I have not seen this spotting on any of my other plants and they are all on the same watering/feeding schedule. Details and pics below, any helpful information or suggestions are greatly appreciated!
California Light Works - Solar System 550 LED
Fox Farms Ocean Mix Soil - 3 gallon fabric pots
Distilled water only
Great White Killer Roots once/week
FloraNova Grow Nutrient - 3 days on/1 day flush, gradually stepping up PPM
I suppose it could be a deficiency of cal/mag. I just kinda figured I would see the spotting elsewhere in the tent, even on other foliage on that particular plant which is not the case.
I also thought with the soil i’m using that I would be ok without cal/mag throughout this grow.
@OlyBoy@Slym3r Running 5.5-6.5 PH with anything I give to the plants, mostly I try to get as close to 6.0 as possible.
@Austin Sorry, let me clarify…I started with clones that I bought from a local nursery that were 2-4 weeks old when I brought them home. I transplanted and did a week of reduced power “clone” lighting before introducing them to the full power veg spectrum which was 2 weeks 4 days ago. So the plants are more like 6-8 weeks old. I don’t plan on switching away from distilled water a this time, other than these spots on the one plant, they have grown wonderfully thus far.
I appreciate the advice! My plan moving forward is to up my PH closer to the 6.5 target and also introduce some Botanicare cal/mag (in a reduced ratio to begin with) into my feedings. I will continue to monitor these spots and go from there. I prefer using the distilled water to have a close to zero ppm start for mixing nutrients and I figured with the ocean mix soil I wouldn’t need to supplement cal/mag during this grow. But, I might be lacking a little. Also, because the plant in question is the tallest and most robust of the 6, perhaps it is showing signs of a deficiency sooner than the others might? At this point I do not believe the spots are a fungus purely because it has not spread to any of the other plants in the tent and does not seem to be getting any worse day by day. Thanks again for all the help, guys!
I have found that certain strains and even plants from the same strain/mother plant require different levels of cal mag and nutrients sometimes. For instance I currently have 2 Durban poison going in the identical environment and media, yet one requires more cal mag and dialed back nutrients vs the other that doesn’t seem to care what I do as long as it’s fed and watered lol.
This is why I use Mantis Buffered Nutrients, even fixed a hard to diagnose iron deficiency in a friends water supply. So much free time because I use Mantis, makes growing so much more rewarding.
Looks like you need CalMag to me as well, I’d run 5ml/gal til problem is corrected and then back down to 3ml/gal for a maintenance dose and ph your input water to 6.5 every time.
U actually need the cal mag from the water. Ro/distilled water, all u r doing is making things more complicated than need to be. If u water your garden outside with tap water then why water your indoor plants with ro. Now spring water is ok. It had calcium in it. But it can be pricey$$$. Every week. I do use spring water on seedlings just because the pppms can affect seedlings. But big plants…you can go thru a lot of $ fast.
If u do run cal mag start very light. And feed water . That stuff can build up fast in soil. But usually if u have a heavy base soil. No need for cal mag. But u r stripping out cal mag with ppm zero water.
