2nd round in same grow space, same problems

[JHake]

Hello RIU.

This grow is starting to show problems that the previous one here did, i'll go with info and pictures of the actual grow:

- Plants are in 2,5g/10L pots. Potting soil is either Klassmann TS-3 and/or potting soil from a local brand composed by a little bit of coco coir, mostly peat and some perlite. Both potting soils state in their labels the presence of NPK fertilizer (but no % for each element). The potting mix also has about 10% EWC added.

- Plants were transplanted from 0,25g/1L pots November 22th. Root health was good, although plants were rooutbounded. Plant health was also good, showing some deficiencies because of constant nutrient needs in that pot.
This is what plants looked like in the little pot before getting more yellow from nutrient needs:


- November 27 plants were watered with fertilizer:
Source water: RO
Fertilizer solution: Advanced Nutrients Sensi Grow Powdered + 1,2% soy aminos.
1,3EC/650ppm. pH meter needs calibration, but watering solution with those fert usually is around pH 6.

In this watering, we failed in achieving desired runoff, maybe it's part of the problem.

- The grow space has controlled temp and humidity, is within veg ranges. But we are suspicious of the intake/outake flow of air.
Lights are led with CREE chips, right now around 500-600ppfd.
The room were the little pots were grown, has the same lights, but better intake air.

- November 29, today plants presented the following symptoms:
* Intervenial chlorosis in upper leaves
* Burnt edges in some fan leaves




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This is the second grow in this space. On the previous one, i started in the project with the symptoms already present.
Pictures from previous grow:



The plants were doing ok in the other room were they were in the 0,25g/1L pots.

Is it possible that medium EC became too high due to initial NPK still available + nutrient watering without enough runoff?
I know that on the previous grow, also a watering with fertilizer was applied in the first days after transplant. Nutrient ratios in that fertilizer were slightly different, but concentration also around 600ppm.

As said earlier i'm suspicious about the intake-exhaust system and the air entering the room.

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Do you guys have any idea of what could be going on?

Thanks.

 

[DanKiller]

Mg deficiency will slowly "burn" your tips and plant, it looks like too much feed but actually it's not enough
You water with RO that's the first culprit why your plants are not getting enough Mg
All your problems are nutrients related as each of them depend on the other to move and do their thing
I would suggest adding Mg Ca to your RO water and only then add nutrients
Also 1.3 EC is not too high but maybe it can be too much, only the plants can tell you that,not people on forums.
you have to look at your plants.
I would reduce the feed for now just for good measure and make sure the water you use are better.

 

[Farmer's Hat]

When was the last time ph meeter was calibrated?

 

[JHake]

Mg deficiency will slowly "burn" your tips and plant, it looks like too much feed but actually it's not enough
You water with RO that's the first culprit why your plants are not getting enough Mg
All your problems are nutrients related as each of them depend on the other to move and do their thing
I would suggest adding Mg Ca to your RO water and only then add nutrients
Also 1.3 EC is not too high but maybe it can be too much, only the plants can tell you that,not people on forums.
you have to look at your plants.
I would reduce the feed for now just for good measure and make sure the water you use are better.

So base water would be now RO+CaMg, any suggestions on ppm for each element?
I have Magnesium Sulfate and chelated Calcium to tune de RO water.
I have gypsum/calcium sulfate for a top dressing if needed, we don't run it in the watering system because it's not totally soluble. I also have Calcium Nitrate, but not sure if i want to give nitrates all the time.

I also recognize the intervenial chlorosis as Mg def, but doesn't it usually appears on lower leaves?

When was the last time ph meeter was calibrated?

Never for the new meter. Previous meter was reading about 6-6,5pH.

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My partner is this grow uses almost all these elements at another grow. Same lights, same soil, same ferts. He uses tap water instead.

 

[Farmer's Hat]

Never for the new meter. Previous meter was reading about 6-6,5pH.

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My partner is this grow uses almost all these elements at another grow. Same lights, same soil, same ferts. He uses tap water instead.

If the other grow isn't having the same problems, then the only two variables that differ (RO WATER, PH METER) must be the source of your issue.
However, lets keep in mind that all plants have preferences. Thats the biggest obstacle when running multiple strains on the same reservoir.

 

[DanKiller]

Listen
RO water tend to screw a lot with your grow if you don't know how to make a proper solution that contains every element in the proper dose
When you grow with salts, go with tap water or learn ratios and nutrients first.
Also you can do EWC with RO and have good results but you need to plan ahead your topdressing and pre potting soil mix and pot size
Anyhow, switch to tap water, add some cal mag (0.3-0.4 EC is enough) and let the soil balance for a few days
The plants will let you know what they need from there

 

[DanKiller]

Btw the thing about this genetics will react like x and this will react like y is only true to a small extant, once you have everything dialed, you should see a very small variations between seeds if any.
Unless you grow some extreme landrace seeds indica or sativa
Most hybrids today grow more or less the same
I have more than 70 seeds in veg now from all sorts of genetics, mostly modern, they all look very good and healthy.

 

[JHake]

Listen
RO water tend to screw a lot with your grow if you don't know how to make a proper solution that contains every element in the proper dose
When you grow with salts, go with tap water or learn ratios and nutrients first.

I do know about nutrients and ratios. In fact, base ferts are tuned since instructions from the label end up with a 1:1 N:K ratio.
Ca:Mg on the last watering was about 3:1. Ca from Calcium Nitrate (part B of the 2 part formula) and Mg from Magnesium Sulfate (contained in the part A of the formula).

Since transplant, only water was given because of the composition of the potting soil. I thought EWC would contain enough Magnesium.

The smaller room from where these plants come from, had similar grow strategies.

I will try the Mg in the water.

 

[Farmer's Hat]

Btw the thing about this genetics will react like x and this will react like y is only true to a small extant, once you have everything dialed, you should see a very small variations between seeds if any.
Unless you grow some extreme landrace seeds indica or sativa
Most hybrids today grow more or less the same
I have more than 70 seeds in veg now from all sorts of genetics, mostly modern, they all look very good and healthy.
View attachment 5442455

For sure. You definitely got your set up dialed in if you can run 70 plants, all from seed, without experiencing any major deficiencies.

Do you top dress dry amendments, in addition to running liquid ferts? Im curious about your approach.
I stopped using liquid fertilizers years ago, and rely solely on top dressing dry amendments. This approach works well for my small operation\hobby. Its obviously not efficient on a massive scale, hence the innovation of fertigation.

 

[DanKiller]

A & B ferts are not enough with RO water to answer Weed needs in a high pace environment (indoor), I mean they are but not a complete enough package
Most of them depend on tap water inputs.
Weed is Mg and Ca hog.
Mg is basically the core element in plants.
Iron in humans.

@Farmer's Hat
I grow in a mix of peat/coco/ewc
When my plants start showing signs of def I start giving salts as full organics is too slow for my turbo like environment haha
I use very small cups for pheno hunts and can't use only ewc or compost.
I do like to topdress some ewc once a month no matter the stage im at, just for good measure and to introduce elements that don't exist in the salts
I have very good results this way, I push them hard every step of the way as I'm impatient

 

[JHake]

Thanks for the answers Dan.

Last irrigation had aprox the following ppm:
N 165
P 43
K 232
Ca 92,5
Mg 28
S 48

Total concentration may have been a little higher or lower, but those are the ratios according to the product label.

 

[Wastei]

A & B ferts are not enough with RO water to answer Weed needs in a high pace environment (indoor), I mean they are but not a complete enough package
Most of them depend on tap water inputs.
Weed is Mg and Ca hog.
Mg is basically the core element in plants.
Iron in humans.

@Farmer's Hat
I grow in a mix of peat/coco/ewc
When my plants start showing signs of def I start giving salts as full organics is too slow for my turbo like environment haha
I use very small cups for pheno hunts and can't use only ewc or compost.
I do like to topdress some ewc once a month no matter the stage im at, just for good measure and to introduce elements that don't exist in the salts
I have very good results this way, I push them hard every step of the way as I'm impatient

You mean some traditional A+B formulas with higher Ca and Mg values than products being sold to amend the issues still doesn't contain enough in the base formula?

Saying A+B formulas doesn't contain enough Ca and Mg without stating what they are or what they contain is plain stupid.

 

[DanKiller]

Huh ?
Most A & B Solutions are not meant to be used with RO water unless you supply more Ca and Mg alongside it.
What are you not following here ?

@JHake take your friend with the tap water, does he have the same issues as yours or does his grow is more streamlined ?

 

[1212ham]

Tap water is a variable, the EC can vary wildly depending on location. My tap is over 1.3 here, .6 at my last house. I use RO.

 

[DanKiller]

Tap water is a variable, the EC can vary wildly depending on location. My tap is over 1.3 here, .6 at my last house. I use RO.

If your water is too harsh (1.3 is crazy hard from tap)
You should use RO and learn about ratios, no way around it
My tap is 0.65 and sometimes it burns young plants very slightly
As long as your not above 0.7 your good
Anything above that is a problem indeed.

 

[Rocket Soul]

600ppfd in veg seems a bit high to me, similar dli as midflower. You can try to fix it with nutes as mentioned above but i would simply lower intensity a little. Youll still see plenty of growth. When you say temps and rh is within veg range what actual values do you mean? Leds always need a bit higher temps than other hid lights.

 

[DanKiller]

600 ppfd is low, for every stage.
That's not the problem.
Plants can coup with a lot of light even from seedling (observe nature)
But they need the proper environment to thrive and make use of all that light
Environment is also the medium/feed you use, not just RH and Temps.
Make sure you balance your environment first, your ph, your feed, until your plants are happy
It may take time, but you wanna do it before you transition to flower.

 

[JHake]

600ppfd in veg seems a bit high to me, similar dli as midflower. You can try to fix it with nutes as mentioned above but i would simply lower intensity a little. Youll still see plenty of growth. When you say temps and rh is within veg range what actual values do you mean? Leds always need a bit higher temps than other hid lights.

25-26° C and 60-65%RH

 

[DanKiller]

I would drop the RH or raise the temps
You want 29-31c at canopy (60-80RH) in veg and 27-29c In flowering (50-70RH). reducing it again at late flowering after the budding has done it's course to even lower then 22-24c (30-50RH) if possible (it helps with trichome formation and mold issues) towards the end.
Max transpiration rates are always high heat high humidity
If you go low heat, go low humidity aswell.