Ec rising IN RESERVOIR

try_hard

Member
It is still getting worse...
@Wastei @Kassiopeija I am sorry because I know I tag you a lot but I think this needs to be fixed.

Last rez change yesterday: 20L, 3ppm NaOCl, 20ml Cm, 60ml A+B f, 20ml Booster, ca 0.75ml pH+ to about 5.8 (now about 5.9-6.0)

I hope those pictures are now better depicting the leaf damage.

@Wastei since you are also running NaOCl, have you ever had this kind of deficiency? Because I thought that the added sodium might be causing a Ca lockout as I read that somewhere. How much Ca/Mg do you add/have in your nutrient solution?
 

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try_hard

Member
It really seems to be worse in the middle. On the outer sides its much better. I further increased the distance to the lights.

@Kassiopeija I tried it and my IR meter cannot be adjusted unfortunately.

What should I do to make them comprehend the light better? Even higher CO2 and Temp?
 

try_hard

Member
My current setup is a bit of a mess. I cant easily lower temps. But I increased the distance to the lights.
The observed damage is still slowly progressing...
As I read more and more about this, I think it may be some issue with availability of nutrients due to too low pH/EC or incorrect RH and temp,...

Maybe its not sufficient CO2...

With some sensors not working accurately (EC and CO2... thank god only the most important ones right now :roll:) and environment being unchangable at the moment due to coding reasons, treatment and diagnosis is definitely hindered.

Do you think that Cal or Mg is just not supplied enough? One consideration is that I am on the lower side of recommendation for nutrient levels but pushing the lights to CO2 enrichment territory. So increasing nutrients could help... But with my sensors not working I dont want to risk having them not only light and heat stressed, but also nutrient burned. Maybe its even underfeeding.

@Wastei @Kassiopeija At this point I hope you can make sense of my all over the place chitchat.

Bottom question to everyone:
How can I distinguish between these scenarios without any EC and reliable CO2 readings?
 
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try_hard

Member
Could that actually be too cold for the amount of light?
Could I see improvements if I raise the temperature?

I read something about heat to light intensity ratio being too light heavy for LEDs. Maybe I should push a few degrees higher?

Thats all speculation though.. If anyone of you thinks that this is bullshit, then you are more than welcome to say so.
 

Wastei

Well-Known Member
Could that actually be too cold for the amount of light?
Could I see improvements if I raise the temperature?

I read something about heat to light intensity ratio being too light heavy for LEDs. Maybe I should push a few degrees higher?

Thats all speculation though.. If anyone of you thinks that this is bullshit, then you are more than welcome to say so.
My flower rooms hardly never got over 25C/77F. Many people on here grow in temperate climates indoors with powerful LED's.

How often do you do res changes? Cheers!
 

try_hard

Member
My flower rooms hardly never got over 25C/77F. Many people on here grow in temperate climates indoors with powerful LED's.

How often do you do res changes? Cheers!
My temp swings from 27°C to 30°C via heating.
RH 50ish%

How strong are your lights and how big is the area?

I have measured about 1200 umol/m²/s in the center and about 1000 outwards (CO2 enrichment territory) with my 420W COB over about 1.2m² (a bit light heavy in the center). My plants seem to do better outwards. I think they don't handle the light as well as they could... I want to get them to cope better with the high intensity lighting in the center (should still be alright with CO2 that I do supply).

I change my res every 7 days but mix always smaller samples so I top up every 3 days most of the time.
What do you think about my Calmag ratio? 1ml/L and bottom recommendation for main nutrient dosage (distilled water, 3ppm NaOCL, 2ml/L A+B, 1ml/L Boost).

Thanks.
 

Wastei

Well-Known Member
My temp swings from 27°C to 30°C via heating.
RH 50ish%

How strong are your lights and how big is the area?

I have measured about 1200 umol/m²/s in the center and about 1000 outwards (CO2 enrichment territory) with my 420W COB over about 1.2m² (a bit light heavy in the center). My plants seem to do better outwards. I think they don't handle the light as well as they could... I want to get them to cope better with the high intensity lighting in the center (should still be alright with CO2 that I do supply).

I change my res every 7 days but mix always smaller samples so I top up every 3 days most of the time.
What do you think about my Calmag ratio? 1ml/L and bottom recommendation for main nutrient dosage (distilled water, 3ppm NaOCL, 2ml/L A+B, 1ml/L Boost).

Thanks.
4x4 650w strip LED. You could probably run slightly weaker mix but it's really hard to give good advices without any data like EC, pH and such. Cheers!
 

try_hard

Member
4x4 650w strip LED. You could probably run slightly weaker mix but it's really hard to give good advices without any data like EC, pH and such. Cheers!
If the pH electrode still works correctly (which I am just assuming at this point), then its almost suspiciously stable around 5.8 to 6.0. (Could be wrong but if you have something in mind, maybe it helps).

650W LED for 1.5m² is even slightly higher than me (assuming high efficient leds, which I assume). Do you know the PAR output by any chance?
If yours handle the light well than I am definitely missing something.
How much CO2 do you add?
 
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Wastei

Well-Known Member
If the pH electrode still works correctly (which I am just assuming at this point), then its almost suspiciously stable around 5.8 to 6.0. (Could be wrong but if you have something in mind, maybe it helps).

650W LED for 1.5m² is even slightly higher than me (assuming high efficient leds, which I assume). Do you know the PAR output by any chance?
If yours handle the light well than I am definitely missing something.
How much CO2 do you add?
Meijiu A8's and ran them in the absolut top in my 240cm/7 feet 10.488 inches high tent. Only the carbon filter between the light fixture and ceiling.

Never fiddled with CO2, never saw the need to do so. Plenty of nugs to go around
comes harvest.
 

Wastei

Well-Known Member
If you're not doing weekly pH calibrations I suggest you start doing that. Storage solution (KCL) and pH 7.0 is all you need.
 

try_hard

Member
I do calibrate weekly but the probe is already starting to fluctuate more than usual. Soon I will have my new sensor setup.

Meijiu A8's and ran them in the absolut top in my 240cm/7 feet 10.488 inches high tent. Only the carbon filter between the light fixture and ceiling.

Never fiddled with CO2, never saw the need to do so. Plenty of nugs to go around
comes harvest.
Hmm ok ok. You must have done really pretty well then. Do you think I could underfeed them (nutrient dosage wise OR maybe even too few cycles...) or is this without EC meter really impossible to say?
 

Wastei

Well-Known Member
I do calibrate weekly but the probe is already starting to fluctuate more than usual. Soon I will have my new sensor setup.


Hmm ok ok. You must have done really pretty well then. Do you think I could underfeed them (nutrient dosage wise OR maybe even too few cycles...) or is this without EC meter really impossible to say?
I don't think they're underfed dosage wise. But I would try doubling the cycles to 10 from current 5(?). As long as you don't heat the water with the pump you're good!
 

try_hard

Member
@Wastei @Kassiopeija I did the measurements you asked for.

all measurments made at the same time:
leaf temp (non calibrated IR thermometer) 29-30°C
air temp: 28.5°C
rel humid: 58.5%
https://vpdchart.com/#C,58,28.5,29.5,0 thats the vpd according to the very referenced page. The shown data point represents my dataset at this moment. If thats true this could VERY MUCH explain rust spots followed by upwards curling slowly spreading in center regions (least air flow and highest amount of PPFD).

Whats your opinion?
 
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Wastei

Well-Known Member
@Wastei @Kassiopeija I did the measurements you asked for.

all measurments made at the same time:
leaf temp (non calibrated IR thermometer) 29-30°C
air temp: 28.5°C
rel humid: 58.5%
https://vpdchart.com/#C,58,28.5,29.5,0 thats the vpd according to the very referenced page. The shown data point represents my dataset at this moment. If thats true this could VERY MUCH explain rust spots followed by upwards curling slowly spreading in center regions (least air flow and highest amount of PPFD).

Whats your opinion?
Temps are to high for hydro in that small space IMO. You will have a hard time keeping the roots cool and happy without a chiller at that temp.

You're better of running slightly lower temps in water culture to keep the water temp down to lower evaporation and keeping nasties at bay.
 

try_hard

Member
Temps are to high for hydro in that small space IMO. You will have a hard time keeping the roots cool and happy without a chiller at that temp.

You're better of running slightly lower temps in water culture to keep the water temp down to lower evaporation and keeping nasties at bay.
I think the root zone is in fact a bit cooler as the rest because the canopy is pretty dense and opaque from above.

Water rez temp is always about 19°C and cooler.

Could this really be enough for microbial infestations of the root zone?
 
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