Leaves losing color and leaving spots

[JS550Fan]

I guess it depends on the particular pool product. Though I used to be a Certified Pool Operator I can't for the life of me recall what the chemicals might be. You could compare to the ingredients used in General Hydroponics' PH control kit, as that is what I, and many others around here, use to adjust pH (not that I do that anymore with my organic grows).
By the way, that kit is available quickly on Amazon (if that works where you are), for a decent price.
Otherwise you could use vinegar.

 

[Bigg Al]

Have you checked under the leaf? Looks like spillage to me but I'm no plant doc.

And these 3 items will help you more. If you dont have them I suggest you get them, if you will continue to grow.

PH up and PH down

Ppm pen(it checks how much food your giving them)

Ph pen. Checks your ph of water, and nute solutions.

Hope this helps!

 

[HonestGR]

Thanks!

Dealing with pH levels is a new science for me. The most widely available substance I can find to lower water pH levels is used for swimming pools and hot tubs. Can I use these or do I need specific a pH down solution for gardening purposes?
How urgent is the need to fix this problem do you reckon? If not urgent I can get back to my site in 5 days, before that and it's going to be a hassle for me..

pH is pretty important. If the plant cannot absorb the nutrients required it could get worse, or additional problems could arise. There are a few things you can use around the house.

I think its baking soda will reduce the pH. Be careful using it not to use too much or it will swing it in the other direction.

I only really use pH up/down bottles from my hydro store, so I wont really know if there are any negitive effects, but I dont think there are any. Maybe do a quick google search to see prior to.

In soil I keep my pH between 5.8-6.3 with the nutrients I run. I always alow it to slightly swing towards either end as nutrients are best absorbed all over that range.

If you always feed at 6.0 if will limit nutrients absorbed, so let her go back and forth!

Hope this helps!


Edit, correction: Baking Soda to bring pH up and vinegar to bring it down. Just woke up, brain is just booting up for the day!

 

[OldGrumpy]

Alright, regarding the pH issue im all set, thanks all for the valuable input.

My only remaining question is how timely this matter needs to be resolved.

 

[Bigg Al]

Alright, regarding the pH issue im all set, thanks all for the valuable input.

My only remaining question is how timely this matter needs to be resolved.

I say leave it alone. Young plant, you'll lose those leaves anyway when she gets older and you defoliate them late in the grow.

 

[Arthur]

What's the starting ppm of your water? Do you have a water report available?
8.1 would have me looking at an RO system.

 

[JS550Fan]

Good point. There is a good chance that the TDS is high. My well water ranges from 75-225 ppm.

As recommended above, a pH pen and a TDS pen are very useful tools to have when growing, and are well worth the cost.

 

[Waira]

- no other signs of trouble, not wide spread or advancing fast, so I'm leaning toward a mild infection or physical damage; nute splash shouldn't cause this unless it was overly concentrated to begin with for any application,... Foliar feeding is a common practice across the whole horticultural industry, including cannabis...
... at 8.1pH, water sounds pretty hard, which can become a problem down the road.. cumulative mineral build-up can screw with both pH and nutrient uptake, but this early on, I doubt it's behind this... look into getting an inexpensive TDS or EC meter, and consider using a low ppm water source; those self fill units are a great deal with perfect water! You can blend them to soften it up...
... pH down, citric acid will work, or a dedicated product for this,... hard water strongly resists correction, the high mineral CaCO3 content is why, so another reason to test that water and maybe start blending it...
... new growth looks fine, so stay on light feeds for now... let's see if it helps slow or halt advancing...

 

[OldGrumpy]

- no other signs of trouble, not wide spread or advancing fast, so I'm leaning toward a mild infection or physical damage; nute splash shouldn't cause this unless it was overly concentrated to begin with for any application,... Foliar feeding is a common practice across the whole horticultural industry, including cannabis...
... at 8.1pH, water sounds pretty hard, which can become a problem down the road.. cumulative mineral build-up can screw with both pH and nutrient uptake, but this early on, I doubt it's behind this... look into getting an inexpensive TDS or EC meter, and consider using a low ppm water source; those self fill units are a great deal with perfect water! You can blend them to soften it up...
... pH down, citric acid will work, or a dedicated product for this,... hard water strongly resists correction, the high mineral CaCO3 content is why, so another reason to test that water and maybe start blending it...
... new growth looks fine, so stay on light feeds for now... let's see if it helps slow or halt advancing...

55 mg CaO per liter is what I could find from public sources, the water is apparently "soft".

One leaf looked more or less dead but the rest of the plant, and other plants are healthy. The PH turned out to be 7.9, I added a small amount of nutrients and used a PH down solution to lower the water PH to 6.5.

Thanks for the help!

 

[OldGrumpy]

Autopsy picture of removed leaf.