Please help ID deficiency.

[Qbgrower]

Hi Folks! Hope everyones well.

Here I have leaves off my 68 day old Autoseeds GSC.

Shes In a mix of 50/50 soil/perlite in 15l Autopot with 2 biotabs and starter pack amendments. Under a 135w quantum board.

Some leaves have started to discolour, dry up and die over the last couple of weeks. I initially fed with around 10ml orgatrex with a sprinkle of bactrex which seemed to help a little. I then purchased some bio pk and fed at 2ml / 1.5l water 4 days ago then 3ml yesterday which looks to have caused slight tip burn although it does seem to have helped the other issues.

My first thoughts are a potassium or phosphorus deficiency. What do you all think?

Thanks in advance for the help.

Cheers
Qb

 

[namvet25]

Need whole plant picture.

 

[Qbgrower]

@namvet25

Sorry mate. I've updated the first post with pics.

Qb

 

[Waira]

-- looks like Cu or Zn defc., immobile (within the plant) micronutes both,... lack-of type defc.'s arecommon with these type of nute products... Biotabs is good, but I find "help" is usually needed by bloom! The problem is, while the nutes do have micro's in them, they have too much N (Orga'), or as you saw, the PK booster can still burn... adding enough of them in to fix isn't going to work, you need a dedicated micronutrient supplement for this,... In bloom, foliar is generally out unfortunately...
Why so much perlite? That's too much mate, you reduce soil's nute holding capacity too much at that ratio,....
What's the water source, pH, ppm? Anything else in the res'?.... it's unlikely, but the in-pot pH could be off, alkaline specifically, and locking out the micro's....

 

[Qbgrower]

@Waira


Used a 50/50 mix as that's what was recommended on the biotabs website but I agree that it's too much. Next grow im planning 70/30 soil/perlite.

Water is tap water with decholorinator and calmag added. pH sits around 6.3 and I have an air stone in the tank and an airdome in the pot. Don't have anything to measure ppm.

What would you recommend? I had a quick read about those deficiencies and it said to flush? I could also lower the pH of my water to maybe 5.8?


Thanks for the help.

Qb

 

[Waira]

that's a strange recommendation by them, very strange,.. none of the growers I know, in soil or coco do this... I guess it works, but that seem way too thin to me,... I'll tag @Biotabs F69 in on this,... likely, it'll have a lot to do with how heavy the soil is, lighter, "fluffier" soil (like Royal Gold King's Mix) won't need near that,.. some other brands I've seen can have more clay-ish, fine particulate components that hold water well, but don't "breath" as readily....
Good on the Bio PK, i don't think that caused the tip burn though,... tip burn is kinda generic, several things can start off that way,... and likely more than one thing is defc.,...
What's the dechlorinator you refer to? Are you sure it's plant safe? Canna' safe? ..might be OK in an aquarium, but not necessarily for cannabis growing,...
Earth Juice Microblast is my go-to micronute supp' - - largely sulfate based so S gets covered too.... dose the pots directly, shut off the valves if needed to dry things out a bit, enough that you can water it in well,... ina way, too bad you're in bloom, because foliar is the best fastest way to deal with this,... but in bloom, you tempt mold-fate with foliars unless done just right,... foliar tends to brown-out the pistil tips too, not a bad thing per se, cosmetic only,...

 

[Qbgrower]

@Waira

I'll try the find where I read the 50/50 mix. I use plant magic soil which is a light mix.

I contacted the producer of my dechlorinator when purchased and they said it was organic, EDTA free and safe for use in edible plants.

It's difficult and expensive to get that earth juice here, would biotabs boom boom spray be an alternative I could use? I've also been advised to get silicium flash?

Thanks for the guidance

Qb

 

[Waira]

Is you water treated with chloramine? ....that's the type that won't gas-off like the typical Cl treatments do by just letting them sit out for a day,.... if it's not, then you can skip the chem treatment and fill a bucket or two and let them sit,...
Neither of those are a good substitute for micronutes supplement, and foliar isn't wise right now,.. residues, mold are issues while in bud.... You'll have to do some research for alternative products in your country, but if you read up on EJM, you what to look for,...

 

[Qbgrower]

@Waira My water report says that chloramine isn't added but the individual chemicals are and it could be formed in the supply. I started using it late on last grow and noticed pretty rapid improvement in nutrient uptake.

I'll have a read at what's in earth juice and try to find an alternative.

Thanks for the help.
Qb