Mother plant nutrient deficiency and or lockout advise please

S

Sir Cannabis

Member
Goal: care for mother plant and cloning
Medium: Rockwool
Strain: Amnesia Haze
technique: from clones
Week: not exact but, past 8 weeks minimum
Phase: vegetative
length plants: between 25 and 40cm
Water: Regular tap water
Watering: limited to the method watering from above with a hose.
Last watering: Few days ago (6 days)
Water temperature: steady 21+ max 23
Nutrients: A, B fluid component, magnesium, nitrogen,
PH: 5.8. EC: 1.0-1.1. Calibrated equipment correctly



Kindly inform me on the cause and advise how to cure. How would you handle this situation? I will update the post asap.

Here is a short chronological description to get the thread started:
- No flush or cleaning applied as of yet since 8 weeks
- Will test PH. I would appreciate your advise on the method of testing. I have a PH pen to test. I do not want to drain and collect the pot for fear of over watering issues. I could extract some rock wool from the top and use water to extract the mixture. Some algae on the top could effect to PH reading.
- Experienced some purple stems caused by slightly colder night time temperatures of 17-18 celsius. Stems are recovering from purple colouring since a week
- Heater failure approx. 2 weeks ago. Temp drop to 12 celcius. The drop in temp happened during sleep night time and was solved the next morning.
- Since 12 celsius heat drop noticed yellowing from nitrogen deficiency. Understandably for I had not given any nitrogen in this cycle. First nitrogen nutrient of this cycle was given 6 days ago. I split the nitrogen dose giving it during watering and consequently also spraying some of the dose on the leafs.
- The following days the green color of the leafs improved. Less yellowing.
- As seen on the pictures leaves are wilting. Meaning the issue is of long lasting nature (1 week).
- the wilting started with the bigger fan leaves below, but currently progressed to develop indiscriminately from bottom to slightly below the top.

My diagnose possibilities for you to understand my headspace:
cause 1: Perhaps a slight and developing phosphorus deficiency accompanied by calcium.
cause 2: Another possibility is under watering accompanied by nutrient lockout from the roots. Medium is rock wool. 6 days ago was my last 1/2 liter per pot watering.

Planned approach:
- test and correct PH in rock wool. Advise required for method of testing. Drain or sample mixed in water
- Split saturated plants from under watered plants.
- Give watering to the latter ( under watered plants ) only using PH 5.5 - 6.5 and EC 1.0. Hydro A, B and a modest amount of magnesium



Please advise according to attached images. Only a 2 of the 8 plants are affected as of yet
 

Attachments

Frost Spectre

Frost Spectre

Member
Sir Cannabis said:
Goal: care for mother plant and cloning
Medium: Rockwool
Strain: Amnesia Haze
technique: from clones
Week: not exact but, past 8 weeks minimum
Phase: vegetative
length plants: between 25 and 40cm
Water: Regular tap water
Watering: limited to the method watering from above with a hose.
Last watering: Few days ago (6 days)
Water temperature: steady 21+ max 23
Nutrients: A, B fluid component, magnesium, nitrogen,
PH: 5.8. EC: 1.0-1.1. Calibrated equipment correctly



Kindly inform me on the cause and advise how to cure. How would you handle this situation? I will update the post asap.

Here is a short chronological description to get the thread started:
- No flush or cleaning applied as of yet since 8 weeks
- Will test PH. I would appreciate your advise on the method of testing. I have a PH pen to test. I do not want to drain and collect the pot for fear of over watering issues. I could extract some rock wool from the top and use water to extract the mixture. Some algae on the top could effect to PH reading.
- Experienced some purple stems caused by slightly colder night time temperatures of 17-18 celsius. Stems are recovering from purple colouring since a week
- Heater failure approx. 2 weeks ago. Temp drop to 12 celcius. The drop in temp happened during sleep night time and was solved the next morning.
- Since 12 celsius heat drop noticed yellowing from nitrogen deficiency. Understandably for I had not given any nitrogen in this cycle. First nitrogen nutrient of this cycle was given 6 days ago. I split the nitrogen dose giving it during watering and consequently also spraying some of the dose on the leafs.
- The following days the green color of the leafs improved. Less yellowing.
- As seen on the pictures leaves are wilting. Meaning the issue is of long lasting nature (1 week).
- the wilting started with the bigger fan leaves below, but currently progressed to develop indiscriminately from bottom to slightly below the top.

My diagnose possibilities for you to understand my headspace:
cause 1: Perhaps a slight and developing phosphorus deficiency accompanied by calcium.
cause 2: Another possibility is under watering accompanied by nutrient lockout from the roots. Medium is rock wool. 6 days ago was my last 1/2 liter per pot watering.

Planned approach:
- test and correct PH in rock wool. Advise required for method of testing. Drain or sample mixed in water
- Split saturated plants from under watered plants.
- Give watering to the latter ( under watered plants ) only using PH 5.5 - 6.5 and EC 1.0. Hydro A, B and a modest amount of magnesium



Please advise according to attached images. Only a 2 of the 8 plants are affected as of yet
Click to expand...
 
Frost Spectre

Frost Spectre

Member
Seems like you already have it figured out.

I would reset the rockwool with RO water or tap water (check the ppm of the tap water and make sure it matches your output). You would be surprised how often you can reset Rockwool. Start with a lower EC from what you normally feed and watch for recovery.

I would definitely use that pH meter. As for the Algae I would invest in some Flora Caps. H202 will take care of the Algae if you can't track them down. I would also remove all that dead plant material from the top of that rockwool, you're just asking for problems.
 
S

Sir Cannabis

Member
Frost Spectre said:
You would be surprised how often you can reset Rock wool.
Click to expand...
Before I "reset" I would like to test the runoff first and collect the appropriate ph/ec difference between medium and runoff.
I am collecting info on the correct way of testing and what method to use(drain or sample) when working with rockwool in pots. I could take a sample or two and test that or drain and collect runoff.

I wonder how often you can reset as you say. Is resetting a.k.a. draining with pH-balanced water not the same as over watering? Is soaking rock wool like a sponge not the equivalent of submerging the roots completely which causes lack of oxygen?

Frost Spectre said:
Seems like you already have it figured out.
Click to expand...
I have not figured it out yet. I am still trying to find the exact cause based on the symptoms in the images. I mentioned 2 causes which are my guesses, but I would like some perspective of experienced growers here before planning an approach. Yesterday I had to water the under watered plants with A, B and a bit magnesium.
 
Frost Spectre

Frost Spectre

Member
Sir Cannabis said:
Before I "reset" I would like to test the runoff first and collect the appropriate ph/ec difference between medium and runoff.
I am collecting info on the correct way of testing and what method to use(drain or sample) when working with rockwool in pots. I could take a sample or two and test that or drain and collect runoff.

I wonder how often you can reset as you say. Is resetting a.k.a. draining with pH-balanced water not the same as over watering? Is soaking rock wool like a sponge not the equivalent of submerging the roots completely which causes lack of oxygen?


I have not figured it out yet. I am still trying to find the exact cause based on the symptoms in the images. I mentioned 2 causes which are my guesses, but I would like some perspective of experienced growers here before planning an approach. Yesterday I had to water the under watered plants with A, B and a bit magnesium.
Click to expand...
Sir Cannabis said:
Before I "reset" I would like to test the runoff first and collect the appropriate ph/ec difference between medium and runoff.
I am collecting info on the correct way of testing and what method to use(drain or sample) when working with rockwool in pots. I could take a sample or two and test that or drain and collect runoff.

I wonder how often you can reset as you say. Is resetting a.k.a. draining with pH-balanced water not the same as over watering? Is soaking rock wool like a sponge not the equivalent of submerging the roots completely which causes lack of oxygen?


I have not figured it out yet. I am still trying to find the exact cause based on the symptoms in the images. I mentioned 2 causes which are my guesses, but I would like some perspective of experienced growers here before planning an approach. Yesterday I had to water the under watered plants with A, B and a bit magnesium.
Click to expand...
We used Rockwool on a large scale operation so I like to think that I know what I'm talking about.

Rockwool is designed to be heavily saturated because it holds onto a lot of oxygen so I wouldn't worry about over watering it. If you're concerned with over watering you can let it dry back to at least 30% saturation but the EC level will rise the more dry the medium gets. This can be a problem especially if you are concerned about lockout issues. Another thing you could do is a salinity test in the media itself. We used this exact monitoring equipment to keep track of the issues you have but wasn't absolutely necessary and wouldn't make much sense in a non commercial operation.

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