Someone help me please: I why is this happening?

[jejukkoo]

i'm trying ebb & flow for the first time ...
everything worked great so far
but a few days ago the leaves started to turn yellow in the middle
the edge of one of them and the whole leaf of the other is yellow
and there are places where I see signs of too much nitrogen

there are places where the ends look like they are nutrient burn burnt but that is impossible under such ppm "i hope"

I write down information that is necessary for you and you, as experts, can help with this
thank you for being here, have a nice day

so:
-50 sativa 50 indica
-photoperiod
-4 week flower
-height 50cm
system :
ebb&flow
tank 60 liter
airpump 35 litres/min
water pump :
15 min run 45 min stop and again and again
use ro water
ph :5,8-6,2
EC : 800-880 (us) the device only shows 88, but you have to multiply by ten
ppm : 400-440
nute : hesi hydro bloom
Composition:

• NPK 3 + 4 + 5
• Nitrogen 3,0%
• Phosphorus 3,9%
• Potassium 5,1%
• Other: magnesium, calcium, sulfate.
• Trace elements: iron, manganese, zinc, copper, boron, and molybdenum.
• Vitamins B1, B2, and B6.
• Plant sugars.
• Amino acids.

+hesi phospour plus
4 ml cal
4 ml mg
-root is Great nice white ...not rot

 

[Sativa1970]

The leaf is showing magnesium and/or nitrogen deficiency. You know the total dissolved salts and what you added but not what the levels of each currently are. Adding it to the res is not a guarantee it will transport to the leaf. You are scavenging resources from mature leaves to feed the plant.Water and air temp can effect transportation and efficiency. Could be a deficiency or a lock out.
Check your temps. Do a full res change. Increase the N on the new mix. Sativa need N in flower so it should be 30% of your P value. I use 3 parts 3-12-6 and one part 7-9-5 in flower. 3x3+7=16N 12x3+9=45P on 50/50 hybrids.

These are must have refences for hydro. Notice high P blocks/ creates a deficiency of N, cal and mag then what leaves it effects.

 

[Sativa1970]

Green veins with yellow leaf is N deficiency. Green leaf with curling brown tips is N burn. Didn't know if you were referring to leaves I didn't see.

 

[jejukkoo]

Thanks for the help guys! I focused on the real problem and unfortunately I have to say that root rot caused the problem! I'm very sad.... I cut off the dead roots, cleaned the system and will try to treat the problem with h2o2! I think the problem was the 21 celsius water

 

[Absorber]

The leaf is showing magnesium and/or nitrogen deficiency. You know the total dissolved salts and what you added but not what the levels of each currently are. Adding it to the res is not a guarantee it will transport to the leaf. You are scavenging resources from mature leaves to feed the plant.Water and air temp can effect transportation and efficiency. Could be a deficiency or a lock out.
Check your temps. Do a full res change. Increase the N on the new mix. Sativa need N in flower so it should be 30% of your P value. I use 3 parts 3-12-6 and one part 7-9-5 in flower. 3x3+7=16N 12x3+9=45P on 50/50 hybrids.

These are must have refences for hydro. Notice high P blocks/ creates a deficiency of N, cal and mag then what leaves it effects.

Nice charts

 

[Sativa1970]

Thanks for the help guys! I focused on the real problem and unfortunately I have to say that root rot caused the problem! I'm very sad.... I cut off the dead roots, cleaned the system and will try to treat the problem with h2o2! I think the problem was the 21 celsius water

I have tried ebb and flow a few times over the years. first time I had a pump fail and second time I fought with temps. 21C is not optimal but also not too hot. 18C-25C is generally the acceptable range. Colder temps hold more O2 so better for the plant growth and bad for bacteria growth. That is how H2O2 kills bacteria, oxygenation. Are you aerating the water? Fill some bottles with water and freeze them. Drop the bottle in the res. After they melt swap them with fresh frozen bottles as needed to get temps down.

 

[Absorber]

I have tried ebb and flow a few times over the years. first time I had a pump fail and second time I fought with temps. 21C is not optimal but also not too hot. 18C-25C is generally the acceptable range. Colder temps hold more O2 so better for the plant growth and bad for bacteria growth. That is how H2O2 kills bacteria, oxygenation. Are you aerating the water? Fill some bottles with water and freeze them. Drop the bottle in the res. After they melt swap them with fresh frozen bottles as needed to get temps down.

I run a flood and drain system in four 20ltr buckets controlled via a bell syphon, my temps were hitting 26°c on stinking hot days i used to put a drop or 2 of bleech into 80ltrs of water to combat root rot and did the frozen bottle thing then I bit the bullet about a month ago and purchased a water chiller, its a godsend bloody ripper it gets my reservoir down to 18.5°c its wicked.
you can see the chiller there with the blue readout and the bell syphon that controls the flood and drain cycle is inside the white vertical pipe on the reservoir.

20240129_213243.jpg

• Absorber
• Jan 29, 2024

 

[safeman]

just to add _ what about light intensity (to close, to much) is always ones last thing to take into account But your issue look like a nutrient problem

 

[Sativa1970]

Nice setup Absorber. Been fascinated by ebb and flow ever since I visited my uncles lab back in the 70s. Every time I set one up I love it, right up until mechanical failure. Quality equipment was harder to get years ago so more DIY and "this might work" involved. Dead water cooler is how I know bought the water bottle trick. My last attempt the pump died mid flower. Capped the drains, added air stones to run DWC while I looked for a suitable replacement pump. Ended up just converting everything to DWC. Fewer points of failure.

 

[jejukkoo]

I have 2 systems ebb & flow! the light gets into one, but not the other! The infected became the one that got light...
so if the problem is really the light, then it is impossible for the other one to have a problem! However, to prevent the problem, I add h2o2 to both tanks. for the infected 1 ml/l every 2 days for the purpose of prevention for the healthy 0.5 ml/l every 3 days I think this amount is not significant but it can help! Guys, thank you very much for taking the time to solve my problem! Do you know any preparation / miracle drug that prevents and protects the roots from destruction? who helped what? I wanted to iron hydroguard, but unfortunately they don't ship here

 

[Absorber]

Nice setup Absorber. Been fascinated by ebb and flow ever since I visited my uncles lab back in the 70s. Every time I set one up I love it, right up until mechanical failure. Quality equipment was harder to get years ago so more DIY and "this might work" involved. Dead water cooler is how I know bought the water bottle trick. My last attempt the pump died mid flower. Capped the drains, added air stones to run DWC while I looked for a suitable replacement pump. Ended up just converting everything to DWC. Fewer points of failure.

Yea this has no timer as the bell syphon does all that and say the pump is to fail im just left with water still sitting in the buckets like a DWC system as I have aerators in each bucket so its got a built in fail-safe because the buckets won't drain until pump fills them enough to cover the height of the bell syphon so unless pump was to fail during drain i should be good

 

[jejukkoo]

it became the infected one. the water rose to the top of the yellow pipe, then when the water pump stopped, the water flowed back into the tank under the tray in 5 minutes..15 little girls hurt this setup

 

[Absorber]

Do you know any preparation / miracle drug that prevents and protects the roots from destruction?

Save up and purchase a chiller $480 this one cost said it was capable of doing 300ltrs im glad I oversized for those hot days .
Its worth the investment for peace of mind

 

[Sativa1970]

You are flooding and draining the white tray with the pots sitting in it, right? You do not want light hitting your water. It will promote algae growth that will suck the O2 out of the water causing a chain reaction. Algae can grow in the water long before it shows any green tint just like a clear running stream has algae. Cool, dark and oxygenated are the keys to keeping your res sterile. You need something on top of that tray with square holes for the pots to sit down in.
This a cloning bucket but the design/light seal of the lid is what I am trying to describe.

 

[jejukkoo]

You are flooding and draining the white tray with the pots sitting in it, right? You do not want light hitting your water. It will promote algae growth that will suck the O2 out of the water causing a chain reaction. Algae can grow in the water long before it shows any green tint just like a clear running stream has algae. Cool, dark and oxygenated are the keys to keeping your res sterile. You need something on top of that tray with square holes for the pots to sit down in.
This a cloning bucket but the design/light seal of the lid is what I am trying to describe.

I think I understand what you want to say
I think a solution could be a Foam Board that I place on top of the tray and cut out the exact size of the pot