Calcium deficiency? Brown spots

[Dr Cannabis]

Even a doctor can get sick I guess, and that relates even more to me, since I'm not really an M.D., and especially not for cannabis.

I have three ladies in a grow.. One tall (110cm), one medium (65cm) and one small (50cm).. They are all in early flowering now.

The medium one has brown spots on one of the leaves..

I enhanced this photo to make the spots easier to... ehm... spot.



And the original in LED/CFL light..



I'm gonna add some lemon juice in the water tomorrow to see if this takes care of the problem. My PH is quite alkaline.

I wonder if anyone has a better solution to this problem? Or if I even got it straight. Could it be boson deficiency instead?

The setup..



Humidity and temps should be fine. So.... WELP! :-(

 

[Waira]

:tiphat:... Yep, that Ca defc. alright! Very common, and an easy fix; do you have a Ca-Mg supplement? A dedicated product is best, but molasses will do in a pinch.... There's plenty of choices for this product,..(I like General Organics).... So, I need to know what you're growing in (soil, hydro'), and if you have done foliar spraying before, as this the fastest way to get stuff into the plant... Otherwise, follow directions on the bottle for your specific set-up,... so, get me that info please, and wellget this fixed up!
Also, your girls look very stretchy to me too, long internodals and very long leaf stems, likely because the light sources have been to high up, particularly the CFL's.... plus the bulbs should be deeper in the reflectors; you're losing a lot of light to the sides,... I'm a largely outdoor grower, so, maybe chat with one of the Mod's in the Lighting forum section about how to dial you set-up in better...

 

[Dr Cannabis]

:tiphat:... Yep, that Ca defc. alright! Very common, and an easy fix; do you have a Ca-Mg supplement? A dedicated product is best, but molasses will do in a pinch.... There's plenty of choices for this product,..(I like General Organics).... So, I need to know what you're growing in (soil, hydro'), and if you have done foliar spraying before, as this the fastest way to get stuff into the plant... Otherwise, follow directions on the bottle for your specific set-up,... so, get me that info please, and wellget this fixed up!
Also, your girls look very stretchy to me too, long internodals and very long leaf stems, likely because the light sources have been to high up, particularly the CFL's.... plus the bulbs should be deeper in the reflectors; you're losing a lot of light to the sides,... I'm a largely outdoor grower, so, maybe chat with one of the Mod's in the Lighting forum section about how to dial you set-up in better...

Heya Waira,

It's in soil with perlite, leca nuts and no bonemeal, and nope, this is my first grow, so I have never tried foliar spraying before. But don't you think it will suffice to add a teaspoon of lemon juice to a gallon of water or so? Foliar spraying seems a bit, well, I dunno, they're in early flowering, and I've read elsewhere that they you shouldn't mist in the flowering phase because it can result in mould when you're indoor growing.

As for the stretch, well, that's most likely because they had to spent the first 22 days of their lives under 15W lamp. There will be light intensity damage if I move the UFO closer, plus they will bend for it. That's the thing with LED, you have to find the spot between bending and light insuffiency. It's a constant balance. The CFLs are as close as they can get with that setup. Sadly.

What would you add to the water before foliar spraying, friend?

 

[Waira]

.... ...soil, good! That makes things easier... I don't know what you mean about the lemon juice, bro', all I've seen that used for is a mild pH adjusting for water/nute' soln.'s and soil; as mentioned, a dedicated Ca-Mg product is best, but molasses can help too, it's just not as concentrated.... but it does have MG and K in it as well, plus the sugars will make the soil microbes very happy! I use it @ 1T/gal for soil drench, about half that for emergency foliar... you must very careful with it this way, as indeed molds will like it too! During veg', it's a simpler, but with a budding plant, you have to a precise sprayer, hitting fans only, top and bottom, and doing your best to spray from the inside out, or sideways, to avoid overspray getting onto the buds....this is true for the dedicated product as well, but they have less sugar, so are a bit less likely to be mold food,... foliar is an emergency fix in the case of budding plants, so do it during lights on, but remove them from full blast light until they dry to avoid potential burning; also, a must for this is a wetting agent, or water spreader; this stuff takes the surface tension out of the water/soln. you're spraying, so it coats evenly instead of beading up and rolling off, etc.,.. basically, the more surface area covered = more gets absorbed... stuff get into the plants through the stoma's, closeable "pores" on the leaf surface, which are involved in gas and moisture exchange, the rest of the leaf surface is sealed up,... so, foliar is a bit tricky and labor intensive during budding, hence the 'emergency' part, but it's the fastest route in,... otherwise, soil will be fine too, just slower,... I don't know how severe it is over the entire plant, but what I saw was early symptoms, not severe ..yet! Either way, get something in the soil ASAP, if you're not set-up for foliar just yet...

 

[Dr Cannabis]

Thanks again chief!

I'm gonna try foliar spraying today, because there's already too much water in the soil as it is now. Their growth has stunned a bit, but they are indeed budding, and it does look more severe now. So I bought a bunch of things over the weekend. Proper fertilizers and gear. I wasn't able to get my hands on some Epsom salt before today.

But here's my new gear and boosters.. Time for chemistry!

 

[Nam80232]

Do you have a ph meter?

 

[Dr Cannabis]

Do you have a ph meter?

Not a proper electronic one, only strips and a really bad and cheap electronic one for swimming pools (pH and Chlorine). I'm waiting for one right now tho. Should be here within the week - at least - I have to go by those color strips until then, sadly.

 

[Waira]

Hey mate! Good score on the nute's, though I'm not familiar with this line,... I see the epsom salts, which is great for Mg and S, but it's Ca you need! Did you get a dedicated supplemental product with Ca in it? What's in your fertilizer isn't enough, you need more, without the other extra nutes,... And a wetting agent? If foliar is what you want to try, these are what you really need,...
>> LOL! Ooops, I missed the part about lemon juice and boron defc.in the earlier post! Yeah, that works for adjusting pH down, so does white distilled vinegar,... And no way, it's not Boron defc.... symptoms don't match, even though Br is largely locked out under alkaline conditions (7.5+)....

 

[Dr Cannabis]

Nope, I couldn't get any cal-mag or anything like that, as I buy everything locally or within a fair driving distance at least. But I got some calcium-magnesium pills made from dolomite lime. I wonder if I can just crush them and feed them in the soil, as foliar spraying seems far more tricky?

 

[Dr Cannabis]

Or how about some regular garden lime? I looked at some in a garden center, and the smallest bag was 15 kilos, seemed a bit lame to get 15 kilos. Oh well, then I have some for the garden as well eih. If it will do of course? I mean, by crushing it thoroughly, letting it dissolve in some water and feeding it into the soil.