Plants going yellow, nitrogen deficiency?

[RoccoG2021]

I’m into week 4/5 of flowering & over the last 2-3 weeks my plants have been getting more yellow. The ph levels have been sitting at 5.8-6.2. I’m using mills basis a & b with mills ultimate pk. I’m using autopot systems.

As I was on holiday I had them in veg for around 6 weeks & now 4 weeks flowering on Tuesday. Do I just need to do a 2 day flush & add a nitrogen booster? I’ll feed from the top to soak the soil ( 60/40 coco pebbles) for a couple of days.

I’ll attach a video thanks

[barney_b]

Your PK is a nitrogen reducer (thank you Farmer Geddon for coining that term). Adding N back into your feed will negate the pk boost and basically just increase your EC.

Drop the PK and your NER will swing back towards Nitrogen.

Maybe a bit more information on your fertigation?

Cheers
B

[mpsj]

I’m into week 4/5 of flowering & over the last 2-3 weeks my plants have been getting more yellow. The ph levels have been sitting at 5.8-6.2. I’m using mills basis a & b with mills ultimate pk. I’m using autopot systems.

As I was on holiday I had them in veg for around 6 weeks & now 4 weeks flowering on Tuesday. Do I just need to do a 2 day flush & add a nitrogen booster? I’ll feed from the top to soak the soil ( 60/40 coco pebbles) for a couple of days.

I’ll attach a video thanks

I'm not familiar with the nutes you are using but you do appear to have a N deficiency. I usually don't see that deficiency any sooner than week 7 which is normal. Good news is your buds look healthy. If it were mine with another 4 weeks to go I would likely add some N only. When adding N in bloom I provide it in the form of powered Amino Acid. In that form it's readily available for a quick fix. I don't see any need to flush but that's just my opinion.

[RoccoG2021]

I'm not familiar with the nutes you are using but you do appear to have a N deficiency. I usually don't see that deficiency any sooner than week 7 which is normal. Good news is your buds look healthy. If it were mine with another 4 weeks to go I would likely add some N only. When adding N in bloom I provide it in the form of powered Amino Acid. In that form it's readily available for a quick fix. I don't see any need to flush but that's just my opinion.

Appreciate the reply. Any specific brand you would use like canna mono? How much would you add? If you could give me a name/brand I would appreciate it. I’m just taking a lucky dip at this stage thanks


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[mpsj]

Appreciate the reply. Any specific brand you would use like canna mono? How much would you add? If you could give me a name/brand I would appreciate it. I’m just taking a lucky dip at this stage thanks


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I use GS Plant Foods Amino Acid Powder labeled 14-0-0. It's strong so I wouldn't use the recommended application rate in water. 1/8th ounce of this Power added to a gallon of distilled water will produce an EC of around 0.5 or about 350 ppm.

[Bethmeg]

How often are you feeding ?

You say you will feed from the top for a couple of days so I’m assuming they are bottom fed ?
A coco/pebble mix won’t wick as well as just plain coco so if feeding just from the bottom that could cause the issues you have.
In fact there is very little coco in a 60/40 mix so if running powerful lights it will need more frequent watering.

Any good npk nutrient fed at the correct rate should see them through,but you have to get it all through the medium

[Shaun]

Your PK is a nitrogen reducer (thank you Farmer Geddon for coining that term). Adding N back into your feed will negate the pk boost and basically just increase your EC.

Drop the PK and your NER will swing back towards Nitrogen.

Maybe a bit more information on your fertigation?

Cheers
B

I remember reading that nutrient affects another, but being that the p/k blocks the absorption of N, wouldnt adding be null? Wouldnt reducing the p/k be more effective? Genuine question, im starting to take a harder look at all this. I like this thread because its a clear case of a deficiency because the symptoms are present in the older leaves at the top of the plant, right?

[Farmer Geddon]

If it is true that adding PK increases yield, then one of 2 other things must be true. 1) Having too high a % of N reduces yield. 2) Growers are using an ec that is too low. Adding PK increases ec and (within reason) the % of N in the mix makes little difference. iow, they could have whacked up the ec of the basic nutes to increase yield.

[mpsj]

I remember reading that nutrient affects another, but being that the p/k blocks the absorption of N, wouldnt adding be null? Wouldnt reducing the p/k be more effective? Genuine question, im starting to take a harder look at all this. I like this thread because its a clear case of a deficiency because the symptoms are present in the older leaves at the top of the plant, right?

In a nutshell, too much of either N, P or K will interact and affect plant absorption of these elements either positively (synergistic) or negative (antagonistic). The key is to have a balanced N-P-K. I never speculate on these interactions simply because they are a unique and very complex set of chemical reactions.
For anyone who want to better understand of these reactions I recommend studying MULDER'S CHART.

[barney_b]

I remember reading that nutrient affects another, but being that the p/k blocks the absorption of N, wouldnt adding be null? Wouldnt reducing the p/k be more effective? Genuine question, im starting to take a harder look at all this. I like this thread because its a clear case of a deficiency because the symptoms are present in the older leaves at the top of the plant, right?

Excess PK blocks N not the presence of it.. But I think that's what you were saying here.

I agree that dropping PK would be the move. I'd drop PK (lower the EC) then use more of my flowering base (raise EC back up) and call it a day.

I sent you a link about mobile and immobile nutrients. Deficiencies can present on the newer leaves too. Usually from semi or immobile nutrients.

Wormhole in 3...2...1...

Enjoy

Cheers
B