Hi guys and gals, first post. I have a little spot on one of my leaves, what could it be?

[SweetSkunk]

Hi AFN,

I am currently growing 12 sweet skunk autos (5 from royal queen seeds and 7 from sweet seeds).

I have noticed a little yellowish spot on of the leaves and wondered what it is. Possibly calcium? The thing is live in an area with really hard water so I wouldn't have thought calcium would be an issue.

Would love to know what you think.

Cheers
SweetSkunk

 

[KrazyDave]

Looks to me like it's where a drop of water has landed. Not sure if that'd do that though

[emoji41]

 

[GoAuto6]

The rest looks hood. Like stated above if it starts to spread I'd worry. Give it a few days. Do you have a soil probe? It could be signs of pH issues starting.. if it spreads. Im in an area that has hard water, I use RO water to feed/water with.

 

[bakEQuatorial]

Did you mist them? Could be a burnt mark. Wild wild guess from a newb....grain of salt required!


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[SweetSkunk]

Thank you all. I do mist them with neem oil, with the lights off of course (I have a constant whitefly problem which is sorted with neem).

I don't water at a set time and is usually when the lights are on, I'll try and water with lights off.

RO water is on the horizon but won't be used for this run.
I don't have a pH probe, are they expensive/necessary? If so could anyone point me in the right direction of a reasonably priced probe? Thanks again!

 

[GoAuto6]

The accurate 8 is what I use. Its worth it you can find them on eBay.

 

[Mike20132]

Thank you all. I do mist them with neem oil, with the lights off of course (I have a constant whitefly problem which is sorted with neem).

I don't water at a set time and is usually when the lights are on, I'll try and water with lights off.

RO water is on the horizon but won't be used for this run.
I don't have a pH probe, are they expensive/necessary? If so could anyone point me in the right direction of a reasonably priced probe? Thanks again!

Unless you have complete confidence in the stability of the growth-medium's chemistry, I'd say a pH probe is pretty much mandatory. And even if you did have complete confidence in it, they are still a good idea to have around.

 

[SweetSkunk]

So it is spreading... What ever it is. I haven't watered since the OP so I don't think it can be burn marks. Here is another picture. Also another plant (2 of them have started out really small, I'm unsure why) is also suffering from the same thing. Any suggestions?

 

[SweetSkunk]

Hi AFN,

I previously posted here about a sick plant. It was suggested it could be a burn mark which I've ruled out or a PH problem.

The problem is spreading so I need some advice.

I am running:

• 12 plants in 15L (3 gal) pots
• 3 X 600 HP's
• Light mix
• Tangs easy feeding schedule

So my next step would be to start checking the PH, which I've only ever done once in a failed Coco run.

How would I go about this? I would obviously need a pH probe and pH water tester. How would I go about calculating pH up or down with my results from measuring the soil and nuted water?

Let's say, just as an example, my soil is pH 6 and my water+nutes was 7.5. what calculations would I do to determine the required amount of pH up or down? And what pH up or down should I use?

I seem to remember in the Coco run that it was not advised to use either the up or down (not sure which one) as it was made up of one of the NPK elements.

Any advice on the pH or what's wrong with my plant would be great!

Many thanks and sorry for the long post

 

[Waira]

What are you growing in, and exactly how hard is the water? Do you have a pH and hopefully a TDS or EC meter to check hardness? Mineral rich water will become an issue if it's bad enough,...cumulative amounts of CaCO3, usually not in available forms will start to drive pH up, interfere with nute uptake,... the spots are odd looking, not the usual color for Ca defc.,... the neem spraying, too muc too often can get the leaves touchy for reactions,...
If you're growing in soil, or peat based soilless, even coco, checking in-pot pH is critical,... As for ROor Di water, you can blend it with your dechlorinated tap water, but you'll need that EC/TDS meter to do it,..... BTW, how close is that light, and what's the T and RH% in there?