needed: leaf splotch diagnosis

[caruzer]

Greetings - appreciate anyones insight here...
just finishing Flowering week 7. I had a few of these splotches on my tallest plant (Sour Diesel) for the last 2 weeks, but just assumed it was light damage. No change until this week, when it appeared on a few stalks of other plants (white widow). Mostly at tips, but some mid-leaf.

System
Indoor, ebb&flow
watering: 3x/day
Medium: Hydroton clay pebbles
Stage: Beginning of week 8 Flowering
Water: using tap @ 180ppm.
Nutes: General Hydro - Mixing to 1240ppm
- using Florabloom, liquid KoolBloom, FLoralicious Plus, and FloraNectar

Recent changes:
Cut out FloraMicro completely.
Increased Florabloom and Koolbloom



Is it nutrients or pests? Should I removed affected leaves?

Thank you!

 

[caruzer]

based on the Marijuana Garden Saver, it could be a calcium deficiency. If it doesn't spread and I'm about 2 weeks from harvest... should I let it be?

 

[coreywebster]

What scale ppm? Seems very high!
Why cut out micro?

No don't remove leaves.

 

[caruzer]

using 500 scale. Target TDS and cutting micro after week 7 are based on recommendation by local experienced growers and the clone provider (based on strains)

Here is my TDS history after mixing nutes - 4 weeks veg, then switched to flower:


For me, TDS always increases as the water is consumed or evaped. The 1240 was 5 days after the last mix. I don't top off the res, but I know some people suggest that.

{added}

I just diluted down to 1180. I agree that I'm at the upper limit for these plants, and there is some sign of nute burn, so I'm backing off.


Any ideas on the leaves? is that calcium deficiency? Thanks.

 

[CannaCountry]

Looks like you're short on a couple things, Ca being one of them. However, you're too far along to be doing much to them. Simply note it for your next grow. I'd taper back your N component; your plants look pretty green and you have a few clawed leaves. Otherwise, it looks like you'll be starting off this new decade on a good note. Good luck friend.

 

[caruzer]

Thanks for the feedback - making notes...
I didn't use any CalMag this round. My tap is ~180ppm and the plants seemed to be quite happy with the water/nutes... until ~ week 6. So perhaps they need a little bit more later in flower. Will also note reduction in N.

I'm curious. I would expect the PPM to be decreasing if plants are consuming nutes, and water level is maintained. I've consistently seen an increase as the water level drops (see below).

is it recommended to keep the res topped off? Should I see a decrease with consumption?

 

[CannaCountry]

I don't run my plants like you, so I can't really advise you on your res or your readings per se. Generally speaking though a plant 7 weeks into her flower cycle is going to eventually slow down.

 

[myke]

Does your res have a lid?As your water drops so should ppm if its not evaporating a lot.Not familiar with ebb flow I do rdwc so I dont really lose much water to evaporation.

 

[caruzer]

Yes - res is covered. It's mostly respiration. I get a bump in humidity after each watering.

I'm just curious if plants should ingest a measurable amount of TDS from the nutes (assuming you could account for evaporation and respiration).

 

[curious2garden]

using 500 scale. Target TDS and cutting micro after week 7 are based on recommendation by local experienced growers and the clone provider (based on strains)

Here is my TDS history after mixing nutes - 4 weeks veg, then switched to flower:

View attachment 4448320
For me, TDS always increases as the water is consumed or evaped. The 1240 was 5 days after the last mix. I don't top off the res, but I know some people suggest that.

{added}

I just diluted down to 1180. I agree that I'm at the upper limit for these plants, and there is some sign of nute burn, so I'm backing off.


Any ideas on the leaves? is that calcium deficiency? Thanks.

No it's not a Ca Deficiency, you're locking out K. I run General Hydroponics three part Flora Series with CaliMagic (their Ca additive) and a Silicone additive. Don't drop the Micro and get rid of everything else. Go simple and get to the finish.

I recommend following their feed chart:

https://gh.growgh.com/docs/Feedcharts/GH_FloraSeries-REC_03216am.pdf

Reduce your TDS to no greater than 900 which gives you roughly 700 nutrients and see how they do. In your next grow add ONE additive if you choose and see how that works. Using many different additives you can't see which variable messed you up.
Best of luck

 

[curious2garden]

Yes - res is covered. It's mostly respiration. I get a bump in humidity after each watering.

I'm just curious if plants should ingest a measurable amount of TDS from the nutes (assuming you could account for evaporation and respiration).

One more thing if your reservoir TDS keeps rising that's a sign you are mixing to much nutrient in solution. You want your res to hold close to steady over it's life. If your TDS drops over time you need to up your nutrients in solution.

 

[caruzer]

What is causing the lockout of K? Is it too much FloraBloom? or the other stuff?

I am using their feedchart, but have found that the recommended concentrations do not achieve the target TDS levels - even as listed on the same chart. plus, they list 1400ppm at stages. I certainly don't mind backing down the nutes... for many reasons.

I'm just starting week 8 flower today. I have a wide variety of strains (I know, bad move, lesson learned), and am now working the harvest timing. My White Widow and Gelato make up the majority of the yield. They have about 30% pistil change, and trichomes are still clear. The Sour Diesel is about 15% pistil shift and also clear trichomes. The rest are much smaller yield and at about the same stage as the WW.

I think im about a week or so from harvest, and am willing to take the Sour Diesel a little early, if necessary.

According to their nute charts... I should be ripening. By strain, they're mostly in the 7-8 week range, I'm about there, too.

So - should I:
1) refresh nutes to 900 PPM using just Micro/Bloom... then harvest when ready.
2) refresh nutes to 900 PPM using just Micro/Bloom... then flush, then harvest as ready.
3) flush now, harvest as ready.

I've been told to flush, but am open to more info. thanks.

 

[curious2garden]

What is causing the lockout of K? Is it too much FloraBloom? or the other stuff?

I am using their feedchart, but have found that the recommended concentrations do not achieve the target TDS levels - even as listed on the same chart. plus, they list 1400ppm at stages. I certainly don't mind backing down the nutes... for many reasons.

I'm just starting week 8 flower today. I have a wide variety of strains (I know, bad move, lesson learned), and am now working the harvest timing. My White Widow and Gelato make up the majority of the yield. They have about 30% pistil change, and trichomes are still clear. The Sour Diesel is about 15% pistil shift and also clear trichomes. The rest are much smaller yield and at about the same stage as the WW.

I think im about a week or so from harvest, and am willing to take the Sour Diesel a little early, if necessary.

According to their nute charts... I should be ripening. By strain, they're mostly in the 7-8 week range, I'm about there, too.

So - should I:
1) refresh nutes to 900 PPM using just Micro/Bloom... then harvest when ready.
2) refresh nutes to 900 PPM using just Micro/Bloom... then flush, then harvest as ready.
3) flush now, harvest as ready.

I've been told to flush, but am open to more info. thanks.

Get rid of everything but Flora Micro, Bloom and Grow (if GH hadn't dropped it to zero). In my 15 gallon res I mix the nutrient solution for 15 gallon in about 7 gallons of water. Then I put in my TDS meter and add water until I reach my desired PPM. If you choose to add CaliMagic add it after you have diluted the solution to where you want. I'd take them to roughly 700 to 900 PPM. Then balance your pH (recheck your pH after 24 hours and adjust for bounce back)

I really don't want to start the flushing war but it's simply not necessary to starve your girls as they are packing on the most weight. I'm hydro and I flush every two weeks with tap water for one feeding and pass a couple gallons through each plant to reduce any retained salt on my grow medium. Your plants flavor etc... comes from a dry and cure not starvation.

 

[lwgt]

You're burning your plants and the thing to drop at this stage of the plant would be the flora grow. You're too late to be adding any grow element.
Don't run without cal/mag ever until the end of grow then drop it as well. 180 tds tap water surely doesn't justify dropping the cal/mag.
You're on week 8...time to slow down on the nutes and develop them trichomes.
"- using Florabloom, liquid KoolBloom, FLoralicious Plus, and FloraNectar" all good stuff for finishing your plants and again the only thing to stop is the grow.
Adjusting your tds doesn't involve dropping nutes it involves regulating them properly. If you water and at your next watering tds is up your plants are not eating. Do not add nutes until you find the problem. Worst case senario you do a flush and start from scratch.
Example: tds are 800. I water and tds goes up to 1200. In 3 days when I water again tds should be roughly back around 800 so I repeat the process. If in 3 days the tds is 1000 mix half a mixture of nutes. If in 3 days the tds is 1200 mix no nutes and just add pure water.
From what you're saying sounds like you have 2 -3 weeks left so I would lean towards option #2 but refresh with everything but grow.
P.S. despite what other people say flower goes like this: weeks 1-3 they shoot, weeks 4-6/7 they pack on their weight and weeks 6/7 to harvest is ripen. I'm an indica fan (sativa time limit can be stretched) but that is the idea. Different strains vary. People that pack on the weight in the last 2 weeks before harvest are out of cycle.

 

[caruzer]

I havn't used any grow in many weeks.

I've never seen TDS drop, and the amount it rises corresponds directly to water loss. Replacing lost water just returns it to original mixed TDS level. I have been hoping to see the plants "suck up nutrients" - and they've been extremely happy, so I suspect they have been enjoying their nutes.... but I have yet to see a measurable "uptake" and I haven't heard anyone say that "your TDS should drop over the week as the plants eat". I'm asking because I want to learn - maybe the TDS is affects concentration and the plants ability to absorb nutes (osmosis type issues) more than it is "readily available/consumable nutes" (ie depleted upon consumption).

I'm not trying to pack on any weight, I'm just trying to finish the cycle. The leave issue was unknown to me, so I asked.
I log the TDS and PH everyday. I haven't had any large fluctuations in either. I keep it right at 5.8, and the TDS is always gradual. I've never seen a 400 pt TDS shift as you suggest. Maybe im missing something...

 

[caruzer]

In my 15 gallon res I mix the nutrient solution for 15 gallon in about 7 gallons of water. Then I put in my TDS meter and add water until I reach my desired PPM.

This makes way more sense. I was estimating and mixing test batches in smaller proportions, but was always an estimate.

I just mixed fresh nutes at recommended levels for 25 gals, in 17 gals of water. the result was 698ppm. this has been my experience with GH recommended nutes. Its a little lower than I was targeting, but since I'm near harvest, I'm gonna let the girls run on this.

Thanks for your comments and suggestions!

 

[GBAUTO]

I've never seen TDS drop, and the amount it rises corresponds directly to water loss. Replacing lost water just returns it to original mixed TDS level. I have been hoping to see the plants "suck up nutrients" - and they've been extremely happy, so I suspect they have been enjoying their nutes.... but I have yet to see a measurable "uptake" and I haven't heard anyone say that "your TDS should drop over the week as the plants eat". I'm asking because I want to learn - maybe the TDS is affects concentration and the plants ability to absorb nutes (osmosis type issues) more than it is "readily available/consumable nutes" (ie depleted upon consumption).

I'm not trying to pack on any weight, I'm just trying to finish the cycle. The leave issue was unknown to me, so I asked.
I log the TDS and PH everyday. I haven't had any large fluctuations in either. I keep it right at 5.8, and the TDS is always gradual. I've never seen a 400 pt TDS shift as you suggest. Maybe im missing something...

I use ec monitoring to see if I'm feeding the right amount of nutes for the plants I'm running. Ideally, if the ec of the system stays constant it means that the plant is using both water and nutrients at an equal rate. Rising ec means the plant is using more water than nutes, so a lower base ec would get it closer to equilibrium. The opposite would be true if the ec is dropping.

 

[caruzer]

Makes sense. Thanks.
In that case, there should be a measurable amount of "consumption" of TDS, assuming you added back the lost volume with distilled water. I'm gonna have to try that.

Based on my chart above, and measurements, it seemed that my res was just getting more concentrated over the week, and that there was no consumption of nutes. What a waste of a lot of nutes! I'm running much leaner now, so we'll see... and I'll compare with my next crop.

 

[lwgt]

That was an EXAMPLE: made easier to understand. Nute drop depends on cycle and health of plants.
You said you've never seen a significant drop, then maybe you have issues. When I was doing 6 and in flower weeks 2-6 they would consume 150-250 every feeding resulting in 6-8oz/plant every 14 weeks.
"I've never seen TDS drop, and the amount it rises corresponds directly to water loss" again...maybe you have a problem, and of course "corresponds DIRECTLY" is overstated. The whole point is to get it as CLOSE as we can.
Now I'm just going to throw this out there. Something to ponder. If you're in a constant state of nute imbalance/over feeding, however minute it may be, you are also in a constant state of potential lockout. Potential lockout would keep res tds levels high with unbalanced/unused nutes and result in deficiencies in the plants. If they're not eating or have ph fluctuations either way a res change would help.
I think a broader look at the plants would help.
What are you using to keep your res and roots clean?

 

[caruzer]

Thanks - yeah, I got that.

There has been no further leaf issue since I posted this. I don't have pH fluctuation. My plants look fantastic, and appear to be eating just fine. I'm nearing harvest and thrilled with my crop. I doubt that they have been in nutrient lockout, but will run the next crop leaner.

I am just trying to make sense of my data.

For example, yesterday, I mixed fresh nutes to 698 using GH recommended levels for week 8 flower. That's about 500 lower than the week before, and a lower TDS result then GH recommends. They've had three feedings on this mix over 24 hours. pH is still 5.82, they drank a gallon (from 20 to 19), and the TDS climbed to 760 (mostly in the 2 daylight feedings, less at night). Plants looks fantastic. I find it hard to believe that they didn't eat anything. I know - it takes more than 24 hours... but this is what my data typically reveals.

I'll drop the levels next crop and see if consumption is more apparent.