Potassium?

Johnnyz28 · Jul 3, 2020

Plant is in its third week above the dirt. Water when soil is dry down to my second knuckle. Basically every 2-3 days. Leaves feel "papery" and these spots just showed up. No liquid nutes, FFOF soil with perlite and some mychorrizae when I planted. Have a 480 Meijiu QB in a 3x3 (dimmed to 60% or so). Have given a small amount of cal mag but that was a week or so ago. The spotting is confined to a couple lower leaves for now. PH 6.3-6.7. Well water I test with an apera pen. Plant is in 3 gal fabric pot.

jondamon · Jul 3, 2020

Time to feed it if you ask me.

inth3shadowz · Jul 3, 2020

Hmm, id be interested in this diagnosis. I have a few about the same size that have a similar looking deficiency. Mine has some yellowing tips though, which I keep seeing is "overfeeding". I haven't fed yet, just in MG Organic.

Johnnyz28 · Jul 4, 2020

inth3shadowz said:
Hmm, id be interested in this diagnosis. I have a few about the same size that have a similar looking deficiency. Mine has some yellowing tips though, which I keep seeing is "overfeeding". I haven't fed yet, just in MG Organic.

I have been too to conservative with the watering. I hit them with more water than normal and they perked right up.

Johnnyz28 · Jul 4, 2020

So unfortunately after the lights came back on it has spread upwards. One of the oldest leaves has shriveled. New growth seems fine, but I feel like I need to figure this out soon we than later.

PadawanWarrior · Jul 4, 2020

Johnnyz28 said:
Plant is in its third week above the dirt. Water when soil is dry down to my second knuckle. Basically every 2-3 days. Leaves feel "papery" and these spots just showed up. No liquid nutes, FFOF soil with perlite and some mychorrizae when I planted. Have a 480 Meijiu QB in a 3x3 (dimmed to 60% or so). Have given a small amount of cal mag but that was a week or so ago. The spotting is confined to a couple lower leaves for now. PH 6.3-6.7. Well water I test with an apera pen. Plant is in 3 gal fabric pot.
View attachment 4613209

Does your well water come out at 6.3-6.7 or are you adjusting it, and if so with what?

Johnnyz28 · Jul 4, 2020

No adjustments, I check it everytime I water tho just to be sure. Runoff is 6.6 so everything seems fine pH wise

PadawanWarrior · Jul 4, 2020

Johnnyz28 said:
No adjustments, I check it everytime I water tho just to be sure. Runoff is 6.6 so everything seems fine pH wise

So it comes out at 6.3-6.7 from the tap? FFOF should be fine for awhile with plain water. Are you watering enough?

This makes me think it might be something else. How close is the light, and what are your temps?

Johnnyz28 · Jul 4, 2020

Temps are 71 at night with light on and 77 during the day. Had 1 day that hit 81 but that was an anomaly. RH is 40-50. Light is 24 inches above the canopy. FWIW the auto I have in there is going swimmingly. 18/6 light cycle.

PadawanWarrior · Jul 4, 2020

Johnnyz28 said:
Temps are 71 at night with light on and 77 during the day. Had 1 day that hit 81 but that was an anomaly. RH is 40-50. Light is 24 inches above the canopy. FWIW the auto I have in there is going swimmingly. 18/6 light cycle.

That's a little cold for LED, but it's not too bad.

Johnnyz28 · Jul 4, 2020

Yeah, I don't think it's temp related either, the pattern and colors look like either potassium or calcium deficiency. Would it be safe to add some calmag next watering?

cobshopgrow · Jul 4, 2020

have you tried to dim further down then 60%?

Johnnyz28 · Jul 4, 2020

Everything slowed way down on both plants when I moved it up or turned it down.

cobshopgrow · Jul 4, 2020

normally they dont need a whole lot of light the first few weeks.

3 weeks after soaking seeds, growen under about 22W older gen COB light.

Johnnyz28 · Jul 4, 2020

I dialed it back to about 50%. I'll get an update on the morning. Hope to see some positive progress over the next week

GBAUTO · Jul 4, 2020

I run the same fixture in my pheno tent.
I run it at 20" above the canopy-50% during veg and 100% in flower.

Johnnyz28 · Jul 5, 2020

This morning. Looks like a yellow tip on one of the new(ish) leaves. I attached a pic of the other plant that's doing fine.

jondamon · Jul 5, 2020

Johnnyz28 said:
This morning. Looks like a yellow tip on one of the new(ish) leaves. I attached a pic of the other plant that's doing fine.
View attachment 4614876 View attachment 4614877

I still call hungry like I did days ago.

you’ve only been feeding with plain water and yet the problem progresses.

plants still look hungry to me.

Johnnyz28 · Jul 5, 2020

jondamon said:
I still call hungry like I did days ago.

you’ve only been feeding with plain water and yet the problem progresses.

plants still look hungry to me.

Well know soon enough. I hit her with 1/4 strength Flora micro and grow. If that doesn't solve it I'm reluctant to just throw nutes at it and possibly make things worse.

Johnnyz28 · Jul 6, 2020

So I checked runoff again and it's coming out at 5.7...that could lock out magnesium, correct? What pH should I use to offset? Do I need to flush?

Potassium?

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