Ec rising IN RESERVOIR

T

try_hard

Member
What should I do acutely? Dilute nutrient solution? If that doesn't help then may that be an actual deficiency that needs more calmag?

Could the added sodium of 1.1mg/L in the nutrient solution coming from the bleach that I added have acted as blocker?
 
T

try_hard

Member
Kassiopeija said:
1ml/l Canna CalMag increases ur EC by roughly 0.5. Your target should be 0.4 but you are only feeding 1/3 of that. That's fairly low esp. when keeping in mind only half of that is actually Ca & Mg - the other is N & S.
Click to expand...
Okay thanks for your input... so you are saying that my problem started just now because they may need more than before?

I also noticed that I had a pH of 7 and cant measure EC right now... (My new electrodes are on the way but until then my current unaccurate only pH will have to do.)
I pulled it to about 5.8. After a few feeds it went to about 6.0.

@Kassiopeija
Should I wait and see what happens after adjusting the pH or should I add about 0.5mL/L right now?
 
Kassiopeija

Kassiopeija

Well-Known Member
Do you know the Lucas formula? there are sheets around giving you an idea how EC can be raised depending on the stage of the plant
 
Thundercat

Thundercat

Well-Known Member
try_hard said:
Ok but I always used 0.3ml Calmag per 1L nutrient solution and the problem just appeared spontaneously.
Click to expand...
HOnestly I just looked back at your post after reading KAss's post. I think I miss read the whole 9ml of cal mag thing. I thought you were using that much per gallon.
 
T

try_hard

Member
Kassiopeija said:
Do you know the Lucas formula? there are sheets around giving you an idea how EC can be raised depending on the stage of the plant
Click to expand...
Ah okay thanks. I think I already stumbled across it some time ago. He is sayings I need nothing but GH micro and bloom 1:2. Do you still use boosters,pk13/14,etc?
 
T

try_hard

Member
Hey guys
Updated pics are here: Im not sure whether it's getting better, stable or worse.

I added 0.8ml/L calmag and lowest recommended for A+B, and 75% of recommended of booster.

Last feed: 20L, everything Canna 16ml CalMag, 60ml A+B, 30ml Booster, 2ml standard bleach (3ppm NaOCl), few drops pH+

@Wastei @Kassiopeija @Pretty much everyone with experience
What do you think about those discolorations and their shape? When I look at cal def online I see rusting and brown spots but my plants have this VERY distinguishable pattern to form exclusively between veins and exactly identical. This must be somewhat of an indicator for a specific type of damage.
 

Attachments

Thundercat

Thundercat

Well-Known Member
I’d have to find the chart of nutrient interactions. It’s also possible that the increased PK boost was to much for the plants and has the calcium or magnesium locked out. It’s been a couple years since I’ve looked at it. I’m pretty sure it’s P that is directly linked to calcium and magnesium uptake.
 
Kassiopeija

Kassiopeija

Well-Known Member
They look heat or light-stressed but this could be due to a nutrition problem making the leaves not being able to cope with all the light. for example K def will reduce leaf water content. But it's hard to say the pics are much blurred, in false light...

maybe rH temps are off you've written you are using CO2? what's all your environmental variables? until they do well I'd place lamps at max height if possible these COBs can cause hotspots
 
T

try_hard

Member
Kassiopeija said:
They look heat or light-stressed but this could be due to a nutrition problem making the leaves not being able to cope with all the light. for example K def will reduce leaf water content. But it's hard to say the pics are much blurred, in false light...

maybe rH temps are off you've written you are using CO2? what's all your environmental variables? until they do well I'd place lamps at max height if possible these COBs can cause hotspots
Click to expand...
Ok my environment variables are as follows:

CO2 about 1200ppm but I'm getting a new meter... Let's just say enriched
28-30°C
35-45% rH
About 5.8-6.2 pH due to swings
Water temp about 18°C
about 1200 μmol/s/m^2 PPFD (420W Luminus COB, 6x 70W each; that is pretty even but I still think it could be Light)
 
T

try_hard

Member
Like you said @Kassiopeija I was thinking the same thing. CO2 enrichment and/or nutrient levels have to be somewhat not sufficient to make them unable to cope with the lighting...

It seems like this whole mystery is about me not having a functioning EC meter.

And the pics are blurry? They definitely aren't to me but I will of course make better pictures in a few hours (If you want I will make close ups of the damage and wide angle pics of the plant overall without artifical lighting and upload it)
 
Kassiopeija

Kassiopeija

Well-Known Member
Hey, tbh the CO2 enrichment shouldnt cause any problems, it's well beyond any toxic proportions...

Do you by chance have an IR thermometer to measure leaf surface temp? (needs to be calibrated to leaves 0.97 IIRC)

It looks as if you adjusted the 4 outer sides COBs to beam more towards the middle? that's strange because usually the cross-lighting that overlaps there should give higher ppfd there even at. the incentive would rather be to have it uniform everywhere. even a cheap luxmeter or handyapp could help to even that out a little here, just forget the numbers.

I cannot really see below the canopy or deep within but it looks as if the lower leaves are less affected by the serrated edge's cupping? maybe some selective pruning of a few of these topleaves could help distributing some of the light into the lower regions as well + guarantee better airflow. but only so that still no light can reach the surface, it has to remain a closed canopy of leaves still.
 
T

try_hard

Member
Kassiopeija said:
Hey, tbh the CO2 enrichment shouldnt cause any problems, it's well beyond any toxic proportions...

Do you by chance have an IR thermometer to measure leaf surface temp? (needs to be calibrated to leaves 0.97 IIRC)

It looks as if you adjusted the 4 outer sides COBs to beam more towards the middle? that's strange because usually the cross-lighting that overlaps there should give higher ppfd there even at. the incentive would rather be to have it uniform everywhere. even a cheap luxmeter or handyapp could help to even that out a little here, just forget the numbers.

I cannot really see below the canopy or deep within but it looks as if the lower leaves are less affected by the serrated edge's cupping? maybe some selective pruning of a few of these topleaves could help distributing some of the light into the lower regions as well + guarantee better airflow. but only so that still no light can reach the surface, it has to remain a closed canopy of leaves still.
Click to expand...
That could definitely be a problem. I did adjust the COBs to target the canopy better.

I bought a light spectrum analyser and measure around 1200 μmol evenly. Although I do measure some peaks. Tomorrow I can adjust the lights to shine evenly and maybe pull them up a bit. It's just that I'm not at peak PPFD what cannabis should be able to handle. Do you think EC increase could help them cope with lighting or would that just be excessive stress overload with them being unable to use it and getting damaged?

I do have an IR thermo, but do not know how to calibrate it. I read about 25°C (which is about 2-3°C cooler than air temp) but one side of the tent tends to be warmer than the other.

A few days ago I tried adjusting air flow to evenly distribute over the canopy slightly downwards and from below relatively sharp upwards.

I do think I saw some improvement over the last two days/24h. More pics coming tomorrow (sorry I forgot)
 
T

try_hard

Member
No. It's definitely getting worse. Not too dramatically but definitely measurable with a photo series. pH of the 25L nutrient solution drifted from 5.5 (I purposely set it lower this time because I knew it would creep up again) to 6.6 in roughly 2 days. They consumed about 3/4 of it. Now I'm going to pH down again. I read that the availability is pretty low in more acidic environments so I thought that I let it rise a bit more.

@Wastei @Kassiopeija What do you think?
 
You must log in or register to reply here.
Top