Brown spots on leaves don't know what it is

Anyone know what this could be? It’s more noticeable when the lights are on and seems to over a pretty good area but then I turn off the lights and take a pic with the flash and you can barely see the spots. Only one of the plants has the spots and the other one has a piece missing off the leaf.

The browning in the leaves appears to be the beginning of cal-mag deficiency. The torn leaf is a torn leaf and nothing to worry about.

You should probably fill out a support ticket to get more detailed responses.

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Here’s the support ticket template for you.

Can you please fill out a support ticket? Please include what type of water you’re using.
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

• 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

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.

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Strain- GSCE Autoflower.
Soil- 707 formula w/ nature’s living soil in the bottom 1/3 and topped with half a bag of fox farms Forrest and ocean.
Vessel- 7 gal smartpot
Ph- water 6.0 from tap. Usually leave out for 24+ hours to help with chlorine.
Indoor tent 3x3
Light- viparspectre 900w full spectrum led
Temps- day 70-76 night 58-62
Humidity- 40-50 day 30-40 night
Ventilation- one ocillalating fan over the plants, two small fans on the top of the tent and a 4in inline exhaust used on low.
No co2

Should I be using cal mag with nature’s living soil?

Sorry about the blurple , only way you can really see it.

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@MidwestGuy @CMichGrower

How are you measuring pH? 6.0 is a bit low, but chances are if you’re leaving it out it may be pH 6.2 just before using. Are you using an air stone or just letting it sit?

It looks like a calcium deficiency. But, is it from low pH lockout or lack of calcium?

Can you do a soil slurry test? Just to get an idea where your soil pH currently sits.

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Last time I checked the soil it was at 7 so I tried to get it down by lowering the water ph. I don’t ph it until right before I put it in. No airstone, didn’t know I could use one. What is a slurry test. Just take some soil out and soak it? @Drinkslinger

It’s weird though, I have two plants and one isnt doing that at all. Also planted both at the same time and the better performing plant is into flower and the one that has the brown seems to be a few weeks behind. @Drinkslinger

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Seems like you have things dialed in.

Just out of curiosity, does your blurple light use 10w diodes? Is ninety 10w diodes how they got to call it a 900w light?

I grow under HPS, MH, quantum board LEDs, and a Kind “full spectrum” blurple. I was having problems with the Kind light causing a similar deficiency in my plant and I got frustrated enough to buy a professional quality light meter. What I discovered is that the light directly under the diodes were pushing the high end of acceptable light while just 10 inches off to either side the brightness falls off to almost unacceptably low light levels.

Make sure your light is at the manufactures suggested height, suggested height for mine is 30-34 inches, and move the browning plant off to the side a little, if possible.

Hope this helps.

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Plants in the same environment can be very different. Sometimes you get a weak one.

I used the apera ph20 years ago. It’s a good meter.

I assume you’re not adding any nutrients, correct?

pH 7 is fine for a living soil. I assume you’re growing this as a “water only” plant? Typically with “ water only” you’d use RO/rain/distilled water. A little chlorine or chloramine in municipal electric water can knock your microbial biome out of whack. Chlorine will dissipate better if you run an air stone for 24 hours. Chloramine will NOT dissipate.

Yes a slurry test uses approx 2oz of soil from mid depth in the pot and 2-3 oz of RO/distilled water. You combine, mix well, let sit for 10-15 min, then measure pH.


I had no idea that I would have to use distilled water. I am getting an RO system hooked up hopefully in the next couple of weeks. I have been giving them that water from the start. No nutrients, didn’t think I should. Should I be adding anything ? Will be switching do distilled water today to see if that helps any. Thank you. @Drinkslinger

I have it set to 28 inches , flowering height is 24 to 28 inches per the manual. Just lowered it the other day from 30in. I am also waiting on getting a better light, didn’t know they aren’t the greatest until after I bought it.


Well it doesn’t use the big 10w diodes like mine so that might be better. Only testing will tell. Does the manufacturer of your light have a chart that discloses different PPFD readings at various heights? My didn’t publish one and now I know why.

I would also like to say that to get all the way through flower without a cal-mag deficiency is difficult to do under the best of growing conditions. The further along you get before it shows up the better, but there is a good chance that it will happen and only get worse.

Look at pictures of other members grows where the plants are approaching harvest and you’ll almost always see some brown crunch leaves on the plants.

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Thank you, so it probably still wouldn’t hurt to use purchase some and add it in ? Negative on the light chart, at least not in the manual. Just this about the height. Should I flush the soil with distilled water?


@Drinkslinger should I worry about roots being in there? Also would it be OK to flush the soil with distilled water?

If you haven’t been adding nutrients then it can not possibly need flushing.

You can add cal-mag but don’t expect the leaves to recover, they will only progress to get worse. At least I’ve never been able to reverse it once it starts, just best to take preventive measures. Move the light higher and slow down the browning by adding the cal-mag.


I’m thinking about 4 inches up and see if that improves or do you figure more or less? Sorry first time so it’s kinda overwhelming lol. @CMichGrower

If you’re using living soil you do not flush, you also do not water to runoff.

Distilled water, or RO is what you want to use.

You can add a little cal mag (I prefer the earth juice version) to your watering schedule.

Most leds don’t have the spectrum that plants need to convert calcium. Hence many growers using leds will experience calcium and or magnesium deficiencies at some point. It’s usually shortly after switching to flower.

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