Brown mark on leaf northern lights x big budd

[sam2016]

Hi guys , I'm back again lol , ive just started week five of my new grow , early flowering , I'm changing from grow to bloom feeds currently feeding 2ml grow and 2ml bloom per litre and today I noticed a brown mark on one leaf of one of the girls , I don't know if its a deffiency , any help would be appreciated , I have a grow journal in the indoor grow section on this site , sorry I don't know how to link it but its just called " Sam's northern lights x big Budd hps soil grow" here's a pic , thanks for looking

 

[Waira]

...closer shot please Sam,... I think it's Ca defc., but some P defc, symptoms can overlap,...

 

[sam2016]

Hey @Waira thanks for the quick reply brother , I took a few better pics today sorry I've only got my fone s camera , I've noticed these marks on some other leaves on this plant too but my other 2 ladies are fine and they are all getting the same feed , I did top this one tho , u think that might have a bearing on it?

 

[Waira]

...Hmm, could go either way,.. are you using Ca-Mg, and LED light? What brand nutes, and frequency of feeds? Is this mid' to upper leaves, or lowers? Sorry Sam, I should have asked for a whole plant pic too, this will help,... feeds are light, so most likely it's a simple lack-of type defc. here, easy to fix,...

 

[Simplicio]

Hey @Waira thanks for the quick reply brother , I took a few better pics today sorry I've only got my fone s camera , I've noticed these marks on some other leaves on this plant too but my other 2 ladies are fine and they are all getting the same feed , I did top this one tho , u think that might have a bearing on it?

Could be something as simple as spilling nutes on the affected leaves, or something as confusing as wrong pH leading to Ca lockout.
If the problems started when you switched to bloom nutes, then the bloom nutes could be the problem. Most of them contain way too much phosphorous, according to chemical analysis of plant matter I've seen.
I'm growing the World Of Seeds version of this strain right now, along with a few other plants, and the NLxBB has been getting gold discoloration on some leaves, while the other plants aren't. This strain might be extra susceptible to those spots.

 

[sam2016]

Sorry @Waira here's some pics I took this evening , I'm feeding plagron nutes , algae grow and bloom , today 1ml grow and 3ml bloom , I went to the growshop today and picked up vitalink cal mag and added 1ml per litre tonight , I'm growing in plagron light mix soil with perlite , my light is a 250watt hps , I've a group journal in the indoor grow section , I'm sorry I dont know how to link it but its called "Sam's northern lights x big Budd hps soil grow" thanks again man

 

[sam2016]

Hey @Simplicio thanks for replying mate , defiantly no spillages on the leaves but like u said maybe the strain , do u have a grow diary on here , I'd love to see some pics of ur nl x bb ladies to compare ?

 

[Waira]

better! So, I'm leaning toward P defc, more than Ca,... what's you water source? With bloom well under way, demand for P is elevating now,.. BUT not having used Ca-Mg yet, pending water source info (tap has some CaCO3 in it, but the pH and a TDS/EC reading is needed to know exactly how much), and given where it's hitting (mid-level), Ca defc. isn't eliminated IMO,.... P can be tapped from fan leaves from here, and lower first usually as well,... I notice you have some tip burn too,.. older, or recent? Isn't Plagron organic, or nearly so? The dosage has been light, so is the soil, so the burned tips are odd considering,...how frequently do you feed? .... I would seriously consider getting a soil pH probe, like the Accurate 8... just stick it in, wait a few, and you'll have critical info about pH, which is some cases, is what's behind certain defc.'s, not just lack of,... less commonly, toxicity (too much of certain nute elements) can cause lockout type defc.'s as well,... So, you're getting Ca-Mg in, might want to elevate that some; what's the recommended dosage on the label?

 

[sam2016]

Hey waira , plagron alga grow and bloom nutes are organic I'm lead to believe , the recommended dosage on the bottle is 4ml per litre which I was giving until I began the transition from grow to bloom I began with 3ml grow and 1ml bloom per litre then 2 and 2 then 1 and 3 , I think I'm going to have to get that pH reader ur talking about , the dosage on the bottle of vitalink cal mag states 1ml per litre until symptoms subside . otherwise my ladies are doing pretty good , I hadn't expected them to grow quite so tall as I'm having height issues with my light now

 

[sam2016]

I'm feeding with every watering sorry I forgot to mention that