Leaf Discolorations

[DevilDog_0651]

Problem: Noticing brown spots on my leaves, which appear to have become present overnight

Strain: Northern Cheese Haze by Mephisto Genetics
Age: 8.5 weeks old
Medium: Mother Earth Coco + Peat Blend
Feed: Base Bloom (3-12-6), Bloom Booster (2-15-4), Smart Tea for microflora etc., Advanced Nutrients CalMag (4-0-0)
Feed Strength: Last feed was around 1/2 stregth
Feed pH: 6.4 (medium is buffered between 6.4 and 6.8)
Feed PPM: Ranges between 400 and 800 or so + roughly 120 water PPM
Temps: Swings from upper 50's to around 80 (growing outside in a shed)
Light: Mars Hydro TS3000 on 20/4, hung at 12-14" or so
Humidity: Whatever it is outside lol
Ventilation: 16" oscilating fan, blowing around the tops of canopy and at light. 8" inline fan moving air around, and a little axial fan mounted to top of shed (probably isn't doing too much)

What do you all think this could be?

 

[DevilDog_0651]

Anyone have any ideas? It looks close to a Phosphorous deficiency, and the nights do get cold and I know that can affect P.

My feed pH is consistently at 6.4 to 6.5, so I don't think it's a pH issue. Should I increase the P amount in my feed?

 

[Arthur]

Could be Phosphorus. The lack of responses is most likely due to the mixing of soil and coco grow styles. Coco answers and soil answers are different. The coco answer would be your pH is WAY too high. No higher than 6.2
The soil answer might be increase feed, or your pH could be a little low, or you have too much calcium, and would need more investigation.

 

[DevilDog_0651]

Could be Phosphorus. The lack of responses is most likely due to the mixing of soil and coco grow styles. Coco answers and soil answers are different. The coco answer would be your pH is WAY too high. No higher than 6.2
The soil answer might be increase feed, or your pH could be a little low, or you have too much calcium, and would need more investigation.

Darnit lol, so I picked the wrong soil, again! Next time I'm just going to use plain old dirt

 

[Arthur]

Darnit lol, so I picked the wrong soil, again! Next time I'm just going to use plain old dirt

Coco is great stuff, I grow in it regularly, but is not soil, it is empty, inert. Great for control. And it doesn't stay too wet... it will grow some real monsters! Hopefully we'll get some help, there are a few around that have been in this spot...

Best part about coco (other than the size of plants) is with issues like this, the answer would be flush and reset to good values and continue. With soil it's a more gradual thing.

I grow in both soil and coco, but not mixed!

 

[DevilDog_0651]

Coco is great stuff, I grow in it regularly, but is not soil, it is empty, inert. Great for control. And it doesn't stay too wet... it will grow some real monsters! Hopefully we'll get some help, there are a few around that have been in this spot...

Best part about coco (other than the size of plants) is with issues like this, the answer would be flush and reset to good values and continue. With soil it's a more gradual thing.

I grow in both soil and coco, but not mixed!

So is peat considered soil? I thought this was a soiless mix. This is what I'm using https://www.mother-earthproducts.com/product/charged-coco/

The bag does say soil on it...But it looks like coco shavings and peat moss lol

 

[DevilDog_0651]

I will look into flushing it out and starting over with the nutrients. Is this okay to do during flower period?

 

[Arthur]

I will look into flushing it out and starting over with the nutrients. Is this okay to do during flower period?

Went and did a little reading, looks to me like the correct pH (might check with mother earth for their recommendations) is 5.5 to 6.2 shooting for 5.8, which would put it squarely in hydro territory.

 

[DevilDog_0651]

Went and did a little reading, looks to me like the correct pH (might check with mother earth for their recommendations) is 5.5 to 6.2 shooting for 5.8, which would put it squarely in hydro territory.

I see, I was told by the grow shop to use 6.3 to 6.8 as this mix is buffered. I'm fairly new to this, so I may have misunderstood what they were saying. I will do some digging. Thank you @Arthur for your help!

 

[DevilDog_0651]

So after speaking with someone else at the grow shop, they said I should be aiming for around 6.0 with this mix. That could explain things! Next watering will be at 6.0 with no nutes.