Indoor help , why does this keep happening?

[bushmasterar15]

Problem: brown spots on some leaves

Medium/grow method: 5 gal. smart pots--ffof soi

Feed: and supplements used: Tags easy feed nutes-- 5ml. per gal cal-mag every 2 to 3 days water ph to 6.5 after nutes

water source: RO water

Strain/age: 60 days from seed,32 days from flower

light used: Platinum 300- on the left is a Roleadro 800 watt COB

Climate:

Additional info:

 

[rick-j]

Thank you Slater, I have been adding cal-mag every watering, 2 to 3 days, 5 ml. per gal. I will strip the bad leaves, but I noticed this am that I am getting brown spots on my far right girl, I hate it!! I will up my cal-mag.

 

[rick-j]

Thanks, ive got 2 girl scout cookies from fast buds, and 1 forest fruit from Amsterdam seed co.

 

[Waira]

.... Ca defc., in part for sure,... RO water is stripped of the pH buffering mineral CaCO3, so it's up to the feeds and supplements to help boost that up; LED does seem to increase demand, not sure if COB vs standard blurple LED are worse than the other for this,... How far away are the lights?
AN is pretty mild, so maybe bump up the base bloom feed some, maybe start with a PK booster now too; I think there's some P defc. happening,.. don't like the pale tops, and I think I see some edge curling which hints at lights too close, and/or too warm, low RH%, strong air movement-- any combo of these can cause this,...
What are the T and RH% in there?
As mentioned, pH is always a possible underlying cause, but you'll need a pH probe to test in-pot... the Accurate 8 is a less expensive way to go,hsoillong probe here)... it's been a solid tool for most folks I know, including me! Or cough up the $$ for a Blue Lab model, but that's also a high maintenance unit because it's an electrode bulb type, like a pH meter, so all the care and calibrating comes with it,....
So, it's important because unless you know what that in-pot pH is, we're all guessing on the cause, and the fix will be different for off pH issues; they must be corrected first, adding more nutes into off pH pot will screw things up more! AN "pH Perfect" refers to when it's in solution only, not once it's in a pot, too many other influencing factors going on in there,... That f'ing OF soil is suspect to say the least, as you've seen,... avoid their soil in the future....too risky for quality control!

 

[rick-j]

.... Ca defc., in part for sure,... RO water is stripped of the pH buffering mineral CaCO3, so it's up to the feeds and supplements to help boost that up; LED does seem to increase demand, not sure if COB vs standard blurple LED are worse than the other for this,... How far away are the lights?
AN is pretty mild, so maybe bump up the base bloom feed some, maybe start with a PK booster now too; I think there's some P defc. happening,.. don't like the pale tops, and I think I see some edge curling which hints at lights too close, and/or too warm, low RH%, strong air movement-- any combo of these can cause this,...
What are the T and RH% in there?
As mentioned, pH is always a possible underlying cause, but you'll need a pH probe to test in-pot... the Accurate 8 is a less expensive way to go,hsoillong probe here)... it's been a solid tool for most folks I know, including me! Or cough up the $$ for a Blue Lab model, but that's also a high maintenance unit because it's an electrode bulb type, like a pH meter, so all the care and calibrating comes with it,....
So, it's important because unless you know what that in-pot pH is, we're all guessing on the cause, and the fix will be different for off pH issues; they must be corrected first, adding more nutes into off pH pot will screw things up more! AN "pH Perfect" refers to when it's in solution only, not once it's in a pot, too many other influencing factors going on in there,... That f'ing OF soil is suspect to say the least, as you've seen,... avoid their soil in the future....too risky for quality control!

Thank you very much, this is the first time ive had this pc on today, I will get back tomorrow first thing, thanks again---

 

[rick-j]

OK, good morning---- thank you to Waira for all your advice. I found a accurate 8 this morning. It says to Sprinkle water on dry soil--how much?, the girls need water today, I put the probe into the girl with the real bad leaves 1st thing this morning, it read 6.5, but is was also pretty dry. I checked the run off 2 days ago and it was 6.5. Temps have been real steady--70--80 at the highest. Humidity has been bad, barely over 30, its real low in N.M., one fan Was blowing directly on the spots of the worst leaves, the other is blowing towards the tent. I adjusted them last night, 1 fan high, 1 low. I also raised the Ptatinum LED 300 to 28" from 24", CHINESE COB to 30" from 26". I will wait till 5:00 after the lights come on to water, hope fully I will get some feed back before then. Once again, thank you very much for helping me. Now, I think its going to be a great day.

 

[rick-j]

PS--- I have been using Tangs auto feeding schedule, I noticed that post was from 2015, is it still a good schedule for a newbie like me?

 

[MR magoo]

at 60 plus days, these girls are almost done. maybe just ph'd water for the next two weeks is all they need. and yup the leaves will look worse as the buds draws from the leaves.
looks like your going to have a decent crop.

 

[rick-j]

Thanks, I really hope for a good crop, have had a lot of problems when I switched to LED, I appreciate your advice.

 

[Waira]

..yup, soil needs to be well moistened, but not soggy,.. water only to, never take pH reading after feeding, it skew results,....
Good on the light adjustments, Platinum lights are pretty fierce,....COB's too! ...between the blasting light and possibly overly strong air movement it might be enough to blow this problem up worse than usual,... pH's are good- so get on that Ca-Mg ....