White Spots on Leaves

[sally]

Dear All,

New to this so would really appreciate your help.

Indoor Grown
Soil Mix
Flowering Stage (6 days)
Water every 3 days (fertlizing 7-7-7 NPK every 2nd watering)

The whitish/yellowish/creamish spots started to appear once in the flowering stage. They are on the largest leaves and the bottom-middle part of the plan.

After research I thought I narrowed it down to two possibilities. pH problem of spider mite, however I searched thoroughly with a magnifying glass and could not find black spots, webs, or eggs. And for pH, I only use bottled water ( ).

Perhaps this is all normal, but thought better safe than sorry.

 

[Don Draper]

Hey OP. I've had spots like those a couple of times; once due to thrips (harder to see than mites, they move fast and can fly when adults), and more recently due to a ph problem. The point of that one leaf seems a little bleached and crunchy, so I'd guess ph. I'm a hydro guy, but what is the ph of your water and run-off?

 

[blackhole]

did you splash nuts on the leaves
does look like thrip damage

 

[Calyx Hunter]

It definitely looks like insect damage. I'd say spider mites. Look closely under the leaves. This is where they feed. Get a good organic spray like neem oil and you can stop them before they take over completely. Good luck!

 

[Calyx Hunter]

Oh and welcome to .com!!!!

 

[sally]

Thank you everyone for your replies so far,

Is it safe to say though that it is either pH (Tip of the leaf curving) or a pest problem and I could start treating for both?

I will measure the pH of run-off water and reply back to you Don Draper, ideally what should it be?

blackhole I did mist the plant a lot in the vegetative stage.

 

[canadarolls]

Welcome!!
Whats your relative humidity?
Can we see a whole photo of your beauty?

 

[GeorgeFoster]

Get a scope or something and look at the underside of those white spotted leaves....sure tell tale sign of spider mites.

 

[Fuzzy Duck]

I think ya mainly looking at a spider mite problem...

 

[Don Draper]

Thank you everyone for your replies so far,

Is it safe to say though that it is either pH (Tip of the leaf curving) or a pest problem and I could start treating for both?

I will measure the pH of run-off water and reply back to you Don Draper, ideally what should it be?

blackhole I did mist the plant a lot in the vegetative stage.

The runoff should be lower than what goes in, about 5.6 - 5,9. Here's a vid

[video=youtube;8lBYuGlvRNA]

[/video]

Looks to me like possible thrip damage over mites, because of the longer spots, almost like little white smears. Mites tend to suck only one spot at a time, and I've had both pests many times. If it isn't mites or you can't see them, it's probably thrips. Get something with Spinosad in it, I love Monterey garden spray, its cheap and effective (one or two sprays should do it), and it doesn't harm any strain I've run across. Mite treatments can be more costly, and can stress plants. Spinosad is gentle and also treats mites in higher dosages. Good luck!

 

[budstud]

Issue appears to be Ca deficit too me. If run-off reveals a root-zone ph that's low Ca will appear.

 

[sally]

Hello All

Thanks Don Draper for the video.

I measured the pH of the bottled water I use and it is 7.5.

I measure the run-off water and it is 5.6

pH problem?

Calcium problem budstud? (Sorry not sure what root-zone pH means)

 

[sally]

I would like to add that the water that I poured into the plant, to collect the run-off water and measure the pH, did not have any fertiliser.

The video said you need pour in the pH water, what does that mean?

 

[budstud]

Hello All

Thanks Don Draper for the video.

I measured the pH of the bottled water I use and it is 7.5.

I measure the run-off water and it is 5.6

pH problem?

Calcium problem budstud? (Sorry not sure what root-zone pH means)

The run-off ph is indicative to root-zone ph. 5.6 is too low for soil, you'll need to bring it up. @ 5.6 you'll start slipping in N/P/K and locking out Mg and Ca. Check out this chart and you'll see what I 'm conveying.

https://boards.cannabis.com/attachm...sted-leaves-some-tips-curled-down-phchart.jpg

 

[Don Draper]

Hello All

Thanks Don Draper for the video.

I measured the pH of the bottled water I use and it is 7.5.

I measure the run-off water and it is 5.6

pH problem?

Calcium problem budstud? (Sorry not sure what root-zone pH means)

Wow, your run off is almost 2 points lower than what you put in. The video says the run off should be 3/4 of a point to a point lower. Seems like your soil is pretty acidic. Like Budstud says, you need to raise the ph of your soil, probably by raising the ph of your water with a ph up products. I'm a hydro guy, so I'll bet one of these soil vets could tell you how to best accomplish this. Good luck!

 

[budstud]

If you don't have nutrients that contain Ca, you could lower the root-zone ph by shooting through tap water that's phed of 7 at least and monitor run-off until it reaches 6.5/6.8 , and if you have a few egg shells that you could crush to powder (about two shells for a teaspoon for smaller plants), you could work this into the top to inches of your soil, it will help eventually but is a slow to uptake. Chelated Ca will get you back on track quickly after root-zone correction. A properly phed root-zone will stop the deficit if corrected but spots will remain.

 

[budstud]

If you don't have nutrients that contain Ca, you could lower the root-zone ph by shooting through tap water that's phed of 7 at least and monitor run-off until it reaches 6.5/6.8 , and if you have a few egg shells that you could crush to powder (about two shells for a teaspoon for smaller plants), you could work this into the top to inches of your soil, it will help eventually but is a slow to uptake. Chelated Ca will get you back on track quickly after root-zone correction. A properly phed root-zone will stop the deficit if corrected but spots will remain.

No way to edit after a given amount of time, button disappears, but meant to say you could "raise" the root-zone ph in first sentence.