Potassium deficiency, nute burn or...?

[Goshenta]

Hey all. Long time lurker, first time poster. Please go easy on me. If there's material explaining this issue at length I'm having troubles finding it. Would love to be pointed in the right direction.

The plant on the left is White Rhino and the plant on the right is Blueberry. I was under the impression White Rhino was a voracious eater.. Had this issue crop up in veg, one of the other White Rhinos stunted so badly I had to remove it from the rest before switching to flower. Gave it to a friend who has been taking excellent care of it.

I started seeing deformities in the leaves no more than a week ago and have actually been using this as a signal to back off on nutrients for everyone else before I see more problems elsewhere. I'm following the FloraTrio drain-to-waste chart, currently feeding everyone at 400ppm in soil. I was giving them all 700ppm as recommended for a while but then I'd start seeing it build up in the runoff so I backed off again. This is my third grow, really starting to dial in on a lot of my issues so any help here would be appreciated!

Lets see what else.. Ah, they were switched to flower on 10/04/2020, I use R.O. water with a starting ppm of 3, I keep my tent quite stable around 68 degrees Fahrenheit, 55-60% humidity at the moment, and since I switched to flower I've been following my chart as closely as possible with the exception of diluting my nutes in order to keep the soil ppm at the recommended range. Oh, and they were recently transplanted into their 5gal finishing pots.

Here's a closer image of the issue. Does not occur on the topmost foliage, so I'm inclined to say it's probably not light burn. It also does not appear to be happening on the other two strains currently growing in the tent. Also isn't very widespread on the plant yet, but it's definitely progressing.

Any ideas? I was thinking I would give it plain R.O. water on the next feeding, 200 after that and back to 400 steady. Everyone else seems to be doing fine around that range for now.

 

[Aqua Man]

Hey all. Long time lurker, first time poster. Please go easy on me. If there's material explaining this issue at length I'm having troubles finding it. Would love to be pointed in the right direction.

The plant on the left is White Rhino and the plant on the right is Blueberry. I was under the impression White Rhino was a voracious eater.. Had this issue crop up in veg, one of the other White Rhinos stunted so badly I had to remove it from the rest before switching to flower. Gave it to a friend who has been taking excellent care of it.View attachment 1046080
I started seeing deformities in the leaves no more than a week ago and have actually been using this as a signal to back off on nutrients for everyone else before I see more problems elsewhere. I'm following the FloraTrio drain-to-waste chart, currently feeding everyone at 400ppm in soil. I was giving them all 700ppm as recommended for a while but then I'd start seeing it build up in the runoff so I backed off again. This is my third grow, really starting to dial in on a lot of my issues so any help here would be appreciated!

Lets see what else.. Ah, they were switched to flower on 10/04/2020, I use R.O. water with a starting ppm of 3, I keep my tent quite stable around 68 degrees Fahrenheit, 55-60% humidity at the moment, and since I switched to flower I've been following my chart as closely as possible with the exception of diluting my nutes in order to keep the soil ppm at the recommended range. Oh, and they were recently transplanted into their 5gal finishing pots.

Here's a closer image of the issue. Does not occur on the topmost foliage, so I'm inclined to say it's probably not light burn. It also does not appear to be happening on the other two strains currently growing in the tent. Also isn't very widespread on the plant yet, but it's definitely progressing.
View attachment 1046090

Any ideas? I was thinking I would give it plain R.O. water on the next feeding, 200 after that and back to 400 steady. Everyone else seems to be doing fine around that range for now.

If its not heat related my first thought would be something like russet mites. May wanna break out the scope and have a look.

 

[redshift75]

whats your temps? that kind of looks like a phosphorus recovery when i try to take em back from purple to green instead of keeping em yellow. are you possibly in a sub 50 temp space at night? or hit sub 50 one night? gives a very dry immobile burn that will turn some leaves to a hard brown crusty like feel. Which i s presented in the leaves that typically getting the most light first. Not the bud but the sugar leaves just below tip tend to be first ones to switch. when you go back and flush with high nutes to balance gives that counter nute burn. Just throwing out a possibility not saying thats what it is. at least for me and my area cold temps at night are always something to factor.

 

[Goshenta]

Basement temps, LED lighting (Mars Hydro TSW2000), good circulation. Lows of 65, highs of 72. Intentionally lowered from 68-75 to help purple the blueberry.

I'll pick up a scope and see what I find. There are some brown specks that I would've otherwise thought to be dirt... But I have no idea how it could've gotten on the leaves, so that makes me suspicious.

EDIT:
Might be a while before I get my hands on that scope.. In the meantime, I actually don't know much about pest control. Assuming it is russet mites or anything else, is there anything I can do to prevent this in the future, or at least control it?

 

[redshift75]

Basement temps, LED lighting (Mars Hydro TSW2000), good circulation. Lows of 65, highs of 72. Intentionally lowered from 68-75 to help purple the blueberry.

I'll pick up a scope and see what I find. There are some brown specks that I would've otherwise thought to be dirt... But I have no idea how it could've gotten on the leaves, so that makes me suspicious.

EDIT:
Might be a while before I get my hands on that scope.. In the meantime, I actually don't know much about pest control. Assuming it is russet mites or anything else, is there anything I can do to prevent this in the future, or at least control it?

yeah so its not going to be phos deficiency from cold temps. in my case it takes the strain at sub 40 degrees. But i believe they say baseline is 50 degrees for roots for onset. really is genetic dependent

 

[Beachwalker]

Whats the pH?
How often do you flush out the soil?
What were your last run-off readings?

 

[Goshenta]

I haven't checked the pH of the runoff lately, but I always check and keep my mix at 6.3. Lets see... I typically don't like to flush my plants, I like to keep them within a certain feeding range to prevent over- or under-feeding them until the very end, but I have flushed all of these gals a few times. The Rhino more than the others, as it seems to be generally eating slower than everyone else despite being the same age. It had this exact same issue in veg, but the burn got 10x worse.. Probably because I thought it to be a light burn, moved my light away and kept the nutes the same.

I have made adjustments to lower feeding on Rhino, but she still seems to be progressing. I have scrogged these gals so it can be challenging to get a good reading off the meters.

Oh and I suppose I should mention I'm keeping the light at 18" above the canopy at the moment. Of my 4 plants, only White Rhino is showing issues.

EDIT:
I totally forgot to give you the numbers. So on the last flush the Rhino was at 1200ppm, flushed her down to 700 with everyone else. She is now suffering where everyone else seems to have flourished. I have since been feeding at 400ppm and getting good runoff around 600-700ppm. I think I need to water tomorrow, so I can get some more up-to-date numbers at that time. I should be able to borrow a scope later tonight and post some pictures on whether or not it looks like mites.

The flush I had to perform in veg... It was bad. Rhino was up near 2400, with everyone else in the 2000's. 3gal pots at the time. They all survived that flush no problem, recovered great. But I was feeding them steady 700ppm at the time and it just seemed to be too much.

 

[Beachwalker]

My guess is you have low soil PH and probably a buildup of salts; recommend you check the runoff and post both pH and PPM

 

[Deadstill]

Looks like the start of calcium toxicity.

 

[Goshenta]

Just checked under the scope, doesn't appear to be mites of any kind thankfully. I'll post runoff pH and ppm tomorrow. Kind of hard to get any kind of good quality picture out of my phone held up to a scope, but, here it is anyway.

 

[Goshenta]

Lot to unpack today. Lets see if I can keep it organized. First off, the issue progressed again overnight. I'm starting to lean towards calcium deficiency/toxicity caused by a salt buildup in the soil, but let me know what you guys think. Here's a leaf I didn't recall seeing any problems with yesterday:

Today was feeding day. I ended up feeding 3 of the plants their standard mix and I gave the problem child White Rhino pure R.O. water. Still no issues with anyone else. I believe today is day 18 of flower, so they were fed according to week 6 of the chart I follow. If anyone wants to check it out, here's the link:

https://gh.growgh.com/docs/Feedcharts/GH_FloraSeries-DTW_03216am.pdf

Following the chart at full strength has proven to be foolish for most of my plants. At the moment they're being fed half-strength. I mix according to the chart for 2 gallons, then I dilute it with an additional 2 gallons, mix and let it sit for 15 minutes to make sure the pH and ppm have settled. Three of the four plants received this water. The pH was 6.3 and the ppm ended up being 391. Spot on with what I've been shooting for. Here are the runoff results of all four plants:

Drunken Gorilla - pH 6.2, ppm 528
Blueberry #1 - pH 6.1, ppm 653
Blueberry #2 - pH 6.3, ppm 653 (consistent. I like it!)
White Rhino - pH 6.3, ppm 524

These numbers seem promising to me. If the issue was salts related, I think watering it with pure R.O. was the right choice here. Bit of extra information I've been dwelling on since the original post.. My entire last cycle was Drunken Gorilla, and I ended up having a nitrogen toxicity that I think might have been caused by the fact that I fed twice the recommended amount of CalMag the entire cycle. They hermied due to a power outage that caused my mechanical timers to malfunction and it wasn't caught in time, so they ended up being cut down early. The reason I bring this up is because I wasn't able to perform a final flush on those plants before I harvested them, and I kinda re-used some of that soil and the roots when I needed to re-pot from 3gal to 5. I don't know if that affects anything, but I figured it was useful information nonetheless. I was able to feed Drunken Gorilla by the chart at full strength with no issues most of the cycle, but I didn't start paying attention to my runoff until the very end. So this is all still very new to me.

 

[Aqua Man]

Let's start over here.

I'm guessing you are in coco? What is the exact makeup of the media?

If so then let's get this feed and runoff sorted

 

[Goshenta]

The starting medium is fresh Happy Frog soil. The filler I used to go from 3gal to 5gal pots was the same soil recycled from a previous harvest with a bit of roots torn up and mixed into it.

 

[Aqua Man]

Ok I think your runoff ppm are low. You ph is absolutely fine.

IMO add 100-150ppm of cal mag to your RO.

Then add 3ml of each.

Ph adjust to 6.2-6.5

Then feed each plant the volume of the pot to help restore the nutrient ratios. Keep that ratio for 2 weeks then lower the grow.

I dont see and signs of tox. I think you need to make sure the plants have good airflow and possibly prune if needed to make sure they do.

Also NEVER feed a plant plain RO water. Water only day should be 100ppm of cal mag and thats it.

Feed feed water. And let the soil dry to about 30% before watering again.

 

[Goshenta]

I don't think I'm following. You want me to add 1/8th a bottle of CalMag to my R.O.? You mean the system? It's only a 4 gallon tank. Not very convenient, I know... But it keeps me off tap water. I'll make sure to keep adding CalMag as a baseline when I flush from now on. I'll also up the dose of it from now on and let you know if that helps.

 

[Aqua Man]

I don't think I'm following. You want me to add 1/8th a bottle of CalMag to my R.O.? You mean the system? It's only a 4 gallon tank. Not very convenient, I know... But it keeps me off tap water. I'll make sure to keep adding CalMag as a baseline when I flush from now on. I'll also up the dose of it from now on and let you know if that helps.

You have a ppm meter yes?

Cal mag vary on concentration brand to brand so....

Take your 4 gal of RO water. Add it at about half dose. Get the RO water to read 100-150ppm with only cal mag added.

Then add 12 ml of each grow, micro, bloom to the 4 gal of RO with cal mag added.

Then ph to 6.2-6.5

Then feed each plant with the volume of the pot they are in.... eg. 5 gal pot give it 5 gal of nutrient solution. This is to help bring the nutrient ratios back in line. Nutrient ratios are majorly IMPORTANT. If you have to mix several batches then so be it. You only need to do this once

Feed feed water. When watering take your RO and add cal mag to reach 100ppm total then water to runoff. Then let dry well 20-30% soil moisture before watering again.

 

[Aqua Man]

Then stick to this for atleast a week with NO more changes and see if the new growth is better. Stop changing things.

Any older growth or damaged leaves will NOT get better no matter if you solve the problem or not.

Plants like stability and changes need to be one at a time. Id you keep chasing things you are going to create more problems then you fix.

 

[Aqua Man]

I don't think I'm following. You want me to add 1/8th a bottle of CalMag to my R.O.? You mean the system? It's only a 4 gallon tank. Not very convenient, I know... But it keeps me off tap water. I'll make sure to keep adding CalMag as a baseline when I flush from now on. I'll also up the dose of it from now on and let you know if that helps.

Fixed it sorry I meant 100-150ppm not ml

 

[Goshenta]

BRILLIANT! I will do that on the very next feed for EVERYBODY. One final note, though.. I am using the entire nutrient line, not just Gro, Micro, Bloom and CalMag, but also everything else listed, as needed. Should I add ANY of those? I actually haven't been making any large adjustments, I've been trying to keep the soil at a very specific PPM. The runoff for White Rhino reading in-line with everyone else is exactly what I've been shooting for this entire time.

 

[Aqua Man]

BRILLIANT! I will do that on the very next feed for EVERYBODY. One final note, though.. I am using the entire nutrient line, not just Gro, Micro, Bloom and CalMag, but also everything else listed, as needed. Should I add ANY of those? I actually haven't been making any large adjustments, I've been trying to keep the soil at a very specific PPM. The runoff for White Rhino reading in-line with everyone else is exactly what I've been shooting for this entire time.

Forget the ppm in the runoff you have a mix of organic soil and inorganic nutrients. Unless its like 2000 just ignore it for now. If this was soiless or coco I would say otherwise.

Ph is the key here for now and your is absolutely fine.

IMO drop the rest of the shit. If you have a terp booster you can use it but at half dose. It will be the one high in sulfur.

All these additives usually do more harm than good and you should understand nutrient relationships before using. They make very minimal improvements when used properly and cause major issues when not. So for a newer grower keep it simple and you will do much better in terms of quality and yield.