Unknown Recurring Flowering Problem

[elunex]

Hey guys,

I've had this problem on 3 of my last grows where I used 10L pots instead of 20L. I'm not sure if coincidental or related to pot size. But there appears to be some kind of problem causing discolouration of leaves that resembles a typical deficiency problem, but having spoken to a few local experiences growers, they were all saying something different as to the cause. The plants are 4 weeks into flower now, and its going to be a long 11 week cycle.

I'm growing in a high quality and trusted soil mix, using GH Bloom (had to cut out micros cause of Nitrogen toxicity). Watering at around 6ph. I've been feeding on every water, which is fairly often due to small pot sizes.

The issue is fairly rapidly progressing, with at least 2 new leaves a day showing the same symptoms. Any input would be great.

 

[Virgin Ground]

Is it actual soil or a soilless mix? What brand? If it is in real soil pH closer to 6.3-6.5. If in soilless your pH is ok. Could go a bit lower, 5.8.
What is your rh and temp?
What is your water source?
Are you using a cal-mag product?
Which light at what distance?
this info will help troubleshoot.

Also take a full plant picture in normal lighting, please.

 

[Emilya Green]

Hey guys,

I've had this problem on 3 of my last grows where I used 10L pots instead of 20L. I'm not sure if coincidental or related to pot size. But there appears to be some kind of problem causing discolouration of leaves that resembles a typical deficiency problem, but having spoken to a few local experiences growers, they were all saying something different as to the cause. The plants are 4 weeks into flower now, and its going to be a long 11 week cycle.

I'm growing in a high quality and trusted soil mix, using GH Bloom (had to cut out micros cause of Nitrogen toxicity). Watering at around 6ph. I've been feeding on every water, which is fairly often due to small pot sizes.

The issue is fairly rapidly progressing, with at least 2 new leaves a day showing the same symptoms. Any input would be great.

Hard to tell for sure since all you have given us is a detached leaf, but I am assuming that you are seeing this problem just in the top of the plant. If this is the case, I suspect you have a calcium deficiency, most of the time caused by pH. There is a huge difference between watering at 6.3 pH and 6.5 pH, especially toward mid to late flower.

 

[Virgin Ground]

I think pH problem also. The poster said they are watering with a pH "around" 6.0.
I think it is a good idea to teach new growers how to troubleshoot. What do you think? Develop that critical thinking?
Eliminating any environmental factors first and go from there? It helped me immensely during my last grow. Grow a better grower....maybe?

 

[elunex]

Is it actual soil or a soilless mix? What brand? If it is in real soil pH closer to 6.3-6.5. If in soilless your pH is ok. Could go a bit lower, 5.8.
What is your rh and temp?
What is your water source?
Are you using a cal-mag product?
Which light at what distance?
this info will help troubleshoot.

Also take a full plant picture in normal lighting, please.

It is a soil grow, full living soil. Brand won't be recognized due to it being a South African brand, however it is currently the #1 used living soil brand for horticulture in the country. Freedom Farms.

RH and temp are: 40-50% and temp around 28'C

Using tap water; and local growers here just use tap water, and don't need additional cal/mag traditionally as the tap water is fairly rich in it.

Lights are Bloomspect and Bestva LEDs at around 40cm.

Worth noting that I've done quite a few grow cycles with the setup and the same methodology without this issue.

My thinking is it was potentially caused by overfeeding of nutrients, causing a salt build up which is preventing the uptake of Magnesium perhaps.

Will post full pictures to come, but to be honest the issue isn't widespread enough to see it from such a distance yet, it's progressing, but it is affecting bottom leaves first - probably 1/3 the way up currently affected. And there's about 2 or 3 new leaves affected a week.

I don't rule out a PH issue, as I did drop down 1 or 2 waterings to 5.8 or so when struggling with calibration.

Also worth mentioning that the leaves tend to also have shiny spots on them in many cases. Almost looks like when one messes nutrients on a leaf, however they are higher up on the plant than I'd expect to see from some spillage.

 

[Emilya Green]

don't need additional cal/mag traditionally as the tap water is fairly rich in it.

It looks like in this case you do need calmag. This is fairly common with cannabis plants. Get some and try it... bet it helps stop the spread of this.