Need help! Brown spots on leaves not sure if its mold or what's going on!

[Smoke2much4good]

The pictures will say it all but I am having a bunch of brown burnt spots on leaves and I'm only 3 and a half weeks into flower so I need to fix it asap! I'm not sure if its mold like leaf spot mold, my water temperature dropped down to the mid 50s for about 5 days, humidity was in the 70s for the first 3 weeks have it down to low 60s high 50s now, daytime temp is always 82 nighttime temp is 75, not sure if thats the issue, or whatever it is I'm just not sure , any help would be VERY much appreciated!!

 

[Smoke2much4good]

[No message]

 

[f-e]

Looks like that well known deficiency, Over feed. Is it on veg food, as N seems to be foremost.

 

[Smoke2much4good]

It's on my normal feed I so every single time with no issues what so ever yea there a veg food a and b but I use less in flower no way that could be I've used this same formula 100 times

 

[f-e]

And yet I guessed that highly unlikely circumstance.
Are you mixing by volume, Or adding it until a meter says so?


Edited

 

[OG_Bishop]

looks like calcium deficiency but it could also be magnesium deficiency. what are you feeding them?

 

[Smoke2much4good]

I'm adding it and check it with the meter everytime

 

[OG_Bishop]

gonna need more info if you want to figure it out... what do you use? how much? what is the ppm? what is the medium?

 

[Smoke2much4good]

Heavy 16 , 1100 ppms right now, usually go up to 1250 during week 4 and 5 and bring it back down during the final weeks, I'm in coco, ph is 5.8 everytime with the occasional 5.7 or 5.9

 

[Creeperpark]

Looks like a light burns from a lack of calcium under LEDs. The amount of salt dissolved in water may also cause a calcium deficiency as it will decrease the uptake of water by the plant.

 

[HempKat]

You say you've used the formula you're giving it now 100 times so I take that to mean you've done 100 grows (or there about). Now I've never seen anything like what you have there in my own grows and I've no experience with working in coco so it's difficult for me to say anything specific. I would say pay close attention to the things Creeperpark says and also what f-e says, they both seem like knowledgeable growers that know what they are talking about.

The one thing I could say to someone with maybe 100 grows under his belt is pay closest attention to anything that's different about this grow compared to your last successful grow. I'm guessing that's why you mentioned the temperature change in the water and the humidity change? I do agree with Creeperpark in that what you're showing in your pictures reminds me most of light burn but I figure that's not a mistake a grower with 100 grows under his belt is likely to make. Now he ties it also to using LED lights, again that's something I've no experience with so I'm reluctant to offer much on that other then if you just recently switched to LED there might be something to look at there. What I have learned about LED's so far is that they behave differently then other more conventional grow lights and people who are using them for the first time tend to have trouble adjusting to them at first.

One thing I can say with some confidence is that it doesn't look to me like any mold I've ever seen.

 

[troutman]

My nutrient solutions have calcium nitrate in them. But I now add extra gypsum to increase my calcium levels
without adding nitrogen. Cal/Mag is nice, but in excess you'll overdose with nitrogen if you're not careful and
cause more problems. Gypsum won't change your pH and also adds some sulfur.

 

[anon710]

The pictures will say it all but I am having a bunch of brown burnt spots on leaves and I'm only 3 and a half weeks into flower so I need to fix it asap! I'm not sure if its mold like leaf spot mold, my water temperature dropped down to the mid 50s for about 5 days, humidity was in the 70s for the first 3 weeks have it down to low 60s high 50s now, daytime temp is always 82 nighttime temp is 75, not sure if thats the issue, or whatever it is I'm just not sure , any help would be VERY much appreciated!!

looks like you have a issue with ph and a build up of salts. how much run off you getting per water and how many watering's per day. Looks to me like you are letting the pots "dry out" too much causing EC spikes during the dry back, that in turn will mess your ph up and you get a lock out.

Like previous poster said you have 100 grows under your belt so you for sure know more than me.

 

[Three Berries]

Calcium acetate gives up it's Ca instantly when mixed with water. 25% Ca by weight.

 

[44:86N]

I am not a fan of growing in coir.

When I have used this stuff, I had major issues with potassium deficiencies, which is what that looks like to my eye.

Also, where is your coir sourced from? My understanding is that Mexican Coir is the best, but coir sourced from SE Asia is grown at sea level and contains a lot of salt. If supplies are getting tight, you may have gotten some low quality coir.

When I was using coir, I did flush heavily prior to use. So yeah, this could be a soluble salt issue. Do you have an EC meter? If yes, test a run through on your soil (using distilled H2O).

I also do not think coir has much of a Ph buffer.

At this point in your grow, I would just stop fertilizing and let the chips fall.

 

[Creeperpark]

I am not a fan of growing in coir.

When I have used this stuff, I had major issues with potassium deficiencies, which is what that looks like to my eye.

Also, where is your coir sourced from? My understanding is that Mexican Coir is the best, but coir sourced from SE Asia is grown at sea level and contains a lot of salt. If supplies are getting tight, you may have gotten some low quality coir.

When I was using coir, I did flush heavily prior to use. So yeah, this could be a soluble salt issue. Do you have an EC meter? If yes, test a run through on your soil (using distilled H2O).

I also do not think coir has much of a Ph buffer.

At this point in your grow, I would just stop fertilizing and let the chips fall.

Well said, friend.

 

[troutman]

Dolomitic limestone is a good buffer if that's what he needs. It will add both calcium and magnesium.