Need a little help with diagnosis

Hi all,
I have Durban Poison Auto-flower plants and believe that they have been hit with Leaf Septoria/ yellow leaf spot.
Does this look like leaf septoria or something different. Organic soil, ILGM fertilizer, bug blaster, root guard and mold shield. Watering every three days or so, 1 day after showing Dry.
Using 5gal buckets with two LED lights at half power. Was staying wet for a few weeks but seems ok at this point as the plants have been sucking up consistently since hitting the flowering stage. Some plants are further along because of seed sprouting problems.


These aren’t needed for normal growing. I would avoid using extra products unless they are needed to address problems.

It looks as though it might be a nitrogen deficiency, but that can happen for a few possible reasons. Lets get some more information about your grow environment.


A support ticket will help us help you. Can you please fill out a support ticket? Please include what type of water you are using (RO, distilled, tap.)

COPY/PASTE the below list into your forum post.

Answer these simple questions the best you can.

If you do not know, or do not use something; Just say so; Or post

NA (non-applicable)

• What strain, Seed bank, or bag seed

• Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF

Soil brand and type

• Vessels: Pots, Grow beds, Buckets, Troths

• PH of Water, Solution, runoff (if Applicable)

• PPM/TDS or EC of nutrient solution if applicable

• Indoor or Outdoor

• Light system

• Temps; Day, Night

• Humidity; Day, Night

• Ventilation system; Yes, No, Size

• AC, Humidifier, De-humidifier,

• Co2; Yes, No

If growing Hydro some additional questions:

-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution

Always try to upload a clear picture of any issues you may have to allow the community to assist you. Pictures taken under natural or white lighting are by far the best.

Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner.


Magnesium defienciency.Get some Cal mag!In the meantime Epsom salt will help.Remove the effected leafs then add 2 tablespoons to 1 gallon of water dont use the whole gallon just about 3ozs!Remember the colors will never return green once they have turned yellow.

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@Drdan63 please fill out the information requested above so we can properly help you. Your plant does not look like it has a cal or a mag deficiency. If a nitrogen deficiency, your yellowed leaves will indeed transition to a darker color of green. Some leaves may not make it, but those that do will heal if a nitrogen deficiency.


I’m with Midwest, more info is needed and I don’t recommend adding anything until you have done some testing.


What strain, Seed bank, or bag seed

• Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF

Soil brand and type

• Vessels: Pots, Grow beds, Buckets, Troths

• PH of Water, Solution, runoff (if Applicable)

• PPM/TDS or EC of nutrient solution if applicable

• Indoor or Outdoor

• Light system- 2- 24"x24" square led grow lights at half power, 6108 lux each.

• Temps; Day, Night 85°f day, 68 night

• Humidity; Day, Night 45 to 60%

• Ventilation system; Yes, No, Size Yes, 400cfm variable speed evacuation fan with charcoal filter.

• AC, Humidifier, De-humidifier, no

• Co2; Yes, No no

Seeds are Durban Poison and Sour Diesel. These are from ILGM.
Using Miracle-Gro organic soil in 5 gallon buckets with good drainage, now… Only used root guard once as i had a drainage issue at the start causing concern. I’ve also sprayed the top of the soil twice with Bug Blaster to get rid of the small flies that come with soil. The plants are spaced a month apart, see drainage issues.
I also run a low speed fan blowing through the plants just above bucket level.

The plants are in a 500sqft shed sealed from light. Lights are running 19 on 5 off as i have 2 photoperiod plants as well. 8 plants total.
PH in run off is generally around 5.3 to 5.8

The rest are faring well

I don’t think this is yellow leaf spot, they just look hungry to me. This may be just not feeding enough or could be a ph issue locking out nutrients.

I see you don’t have ph and ppm listed in your support ticket, do you have tools to test this? If not, I would make them a priority. These are the two things that will help you troubleshoot plant issues and potentially keep you from having any plant issues. Buy a quality ph tester, you can get by with cheaper tds/ppm/ec pen if you’re on tight budget.

Miracal gro can be tricky for even experienced growers, so don’t fret too much. In the future try a higher quality orhanic potting soil that doesn’t have the time released nutrients. I like roots organic original blend, but there are plenty others too.

Thanks and sorry for the delay in response. I’ve been away as well as busy with the plants. I realized that the yellowing was a self inflicted wound. I ended up with what looked like just a few aphids. I mixed a spray bottle of Bug Blaster and lightly sprayed.
Soon after I posted my questions I found a green mold in the bottom of the spray bottle I used for the Bug Blaster. Evidently I didn’t get it completely clean. It was used for last years BB so I guess I got a little slack in my cleaning.
Luckily I caught it just in time. I cleaned all my bottles with hydrogen peroxide then boiling water. I then mixed new Bug Blaster, still had the aphids, and Mould Shield.
Luckily the Mould Shield seems to have worked as the plants seem to be recovering. Getting greener. And yes, the aphids are gone. Auto-flower are rapidly approaching harvest so just flushing from here. There’s always problems to learn from. Wish me luck.

I appreciate your response and help.
I’m sorry for not including everything on the questions but my copy and paste skills suck.
PH run off runs fairly consistent between 5.4 to 6. I don’t own a ppm meter, yet, but I’m finding I need one as you recommend.
The Miracle-Gro organic soil was a last minute decision as finding my preferred local supplier had switched away from their organic. I originally had the soil but ended up with a drainage problem causing me to loose 10 seeds. I dumped the soil as I was afraid of mold.
Anyhow… The yellowing leaves was a self infected wound.
I had a few aphids show up so made up a spray bottle with Bug Blaster and sprayed them. I soon realized there was what appears to have been mold in the bottom of the bottle.
I cleaned everything out with hydrogen peroxide then boiling water. Mixed new BB as well as Mold shield.
The mold shield seems to be working as the leaves are looking much better and getting greener. The aphids are gone now as well. Wish me luck.

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Always, and as much as possible!

Looks a little like calcium deficiency