Could someone identify this nute deficiency please

Hi guys,
So this is a sativa Jamaican Peal non auto which im growing in the ground in a coco-perlite mixture.

It's mid June so it's still a long way off flower and I've just been feeding it standard nitrogen high Veg nutes.

I checked the PH today and it was 7... I believe this is too high for coco, it wasn't so high a couple weeks ago. So yeah here's a photo as I was unable to find a diagnosis for it online, the white marks are very unusual and these discolorations are occurring around the middle o the plant in medium aged leaves.

Please tell me what you think I should do. Do you guys recommend the 'PH down' solutions you can buy? They seem abit strange to me, like they could be full of toxic chemicals but I'm no pro grower or scientist so correct me if I'm wrong.

Thanks a bunch,
Jah Bless

Better plant picture please. Thats just a leaf.

Alienwidow said:

Better plant picture please. Thats just a leaf.

Click to expand...

The leaf discolorations are just around the middle of the plant.

Some of the branches are wilting slightly, not as sturdy as they should be. Also a few recent supercrops I've done are taking way too long to heal...
7PH is 2 high 4 coco right?

The plant doesnt look that bad. Could use some bamboo stakes maybe. Is it just a couple leaves dying?

ph for coco should be between 5.8 / 6.5 i use phosphoric acid to ph down, some nutes have this acid as part of there ingredients, you also need to vary the ph (high/low) between 5.8/6.5 other wise you will have MG deficiencies, are you using coco specific nutes, or just any old stuff ?

bobtokes said:

ph for coco should be between 5.8 / 6.5 i use phosphoric acid to ph down, some nutes have this acid as part of there ingredients, you also need to vary the ph (high/low) between 5.8/6.5 other wise you will have MG deficiencies, are you using coco specific nutes, or just any old stuff ?

Click to expand...

Just organic 'cannabis' veg nutes from my local garden centre, they are pretty widely used in spain and they've served me well over the last 3 years. So yeah where could i find phosphoric acid dude? what kinda product is it? should i just get a 'pH down' solution from my local growshop for convenience and reliability?

No one else got any help? I have no f**king clue what the white/silvery and orange/rusty sort of smears are... they're not pest problems, its a nutrient thing and I guess you would call it mobile as only the lower growth is being affected.. someone?

Yes get PH down solution if you are in coco. Sounds like PH is your issue. If it isn't already it will be soon enough.!
Check out this link and read the whole page. You have a better view of your plants, I am going on the one close up shot of the leaf. I may be off with my diagnosis, read it and see if you think it applies to you. If not then still read it because a lot of the info regarding PH is still relevant to you been in coco(counted within the hydro category) Wrong PH is the biggest cause of most deficiencies (not including organic soils). Correct that and many of problems will stop spreading.

http://www.growweedeasy.com/phosphorus-deficiency-cannabis

You also said "white marks" , cant see from the photos but also check out this just in case, always want to rule this out early or rule it in and get it dealt with..
http://www.growweedeasy.com/spider-mites
Again, this may not be your problem but you wana make damn sure is isn't because leaving it undealt with will screw you totally. Better to be safe than sorry with those little shits..

Here is a chart showing the nutrient uptake PH ranges which will help you understand why it helps to vary the PH between a certain range as bobtokes mentioned. You want to look at the side that represents Hydro. You can see there is a spot around 5.8 that will rob you of uptake of both Magnesium and Calcium, this is why you want to water both above that range and below that range, from one water to another or every few waters.


Good luck

most ph down solutions that hydro shops sell are phosphoric acid, just under a different name and a bigger price tag