Overfertilization or potassium deficiency?

[Paranoidis]

Hey Guys!
In Advance: Please excuse my bad grammar!
I'm growing some 'Taomatic' by TopTaoSeeds.
150w hpi, Biobizz nutrients, 6l pots with high quality flower soil.

http://de.seedfinder.eu/strain-info/Tao_Matic/Top_Tao_Seeds/

Those Ladies were in vegetative stage for about 8 weeks.
They're about 1,80m high right now....wow!
After 8 weeks I decided to drop the lights from 18/6 to 12/12, because they didn't flower. Harvest Date should be around 10th of May.
After about 5 days on 12/12 the preflowers matured faster and many pistils started growing.
From this point I fed them with 5ml\l BioBizz BioBloom Fertilizer and 2ml\l of BioBizz BioGrow.
Both are based on organic nutrients.
Today the 5th week of flowering began and I'm pretty disappointed in thier bud's size. The stretching stoped about 6 days ago.

For about 1 week one of my plants looks sick and the buds stopped getting bigger. Because this is my first grow, I'm not sure if it's a potassium deficiency or overfertilization.

I really hope you guys can help me, I got some really valuable information by reading in your forums, big thx so far...especially for the advice of 12/12 flowering trick!

If you need more pics or further information let me know.

All the best,
paranoidis

 

[Headbudz77]

This seems to me as both, but it's a bit over my head, I see Cal Mag def but I also see N toxi. So since you did not mention pH and I know biobizz really changes the pH I dare say you might have a nute LOck.
Again I'm still learning the ropes, let me see if one of the masters can help. @Waira @Dudeski


https://www.autoflower.org/threads/4-strains-3rd-grow.58760/

 

[Heavily Medicated]

Looks like both P and K showing a little demand. Judging by bud size, you are about right when plants have a large increase in demand for P and K. Check your medium pH, and if good, go with some P/K booster and also CaMg demands increase now too.

 

[Paranoidis]

Hi Guys,
thx for your fast support! I'm really glad about your replies!
@Headbudz77
This was one of my thoughts, too. Because of the pretty dark leaves I mentioned that there is no more 'space' for other nutrients inside the cells.
But I'm very doubtful because I really have no experience about the plants' demands.

@Heavily Medicated
Ok, so the water's ph is 7.5. I'm sure because I measure the water every week because of my aquarium.
I don't have the possibility to measure the soil's ph within the next few days.
The nutrients manufacturer says that there's no ph adjustment required, the organic fertilizer keeps the ph in the right level and the soil buffers it as well.
But maybe the 6L soil's buffer is exhausted now because of the long running vegetative stage.
I asked google if I can use mineralic PH Down to adjust the PH precisely and sustainable and many people had big issues after using ph down in combination with Biobizz fertilizers. So that's why I'm pretty afraid.


Thank you so much guys! I do really love my Babies and I want them to get healthy again ; )

 

[Headbudz77]

The water pH is not too bad but what about after you add the nutes.
Check that pH and let me know. If I recall I dropped biobizz because I could not keep a good pH. After nutes my pH was 9,5 and no soil is going to buffer that without consequences.
But it was my first grow, and so very susceptible to mistakes and frustrations. Also you might want to get a ppm meter.
In the end I invested in RO system and that was that.
Good luck with your girls


https://www.autoflower.org/threads/4-strains-3rd-grow.58760/

 

[Paranoidis]

Hey Headbudz77,

I'll measure the PH after adding biobizz within the next few hours, I'll let you guys know!
I just ordered a ph meter, so I can measure the soil's PH.
Because I don't use mineralic fertilizers I wonder if it's useful to buy a ppm meter...? There shouldn't be any salt in the soil whilst using organic nutrition... right?

A RO System could be useful, got some issues about the aquarium in the past, too. Maybe someday, first I want to keep it simple and organic.

Have a nice weekend guys!

 

[Heavily Medicated]

Hi Guys,
thx for your fast support! I'm really glad about your replies!
@Headbudz77
This was one of my thoughts, too. Because of the pretty dark leaves I mentioned that there is no more 'space' for other nutrients inside the cells.
But I'm very doubtful because I really have no experience about the plants' demands.

@Heavily Medicated
Ok, so the water's ph is 7.5. I'm sure because I measure the water every week because of my aquarium.
I don't have the possibility to measure the soil's ph within the next few days.
The nutrients manufacturer says that there's no ph adjustment required, the organic fertilizer keeps the ph in the right level and the soil buffers it as well.
But maybe the 6L soil's buffer is exhausted now because of the long running vegetative stage.
I asked google if I can use mineralic PH Down to adjust the PH precisely and sustainable and many people had big issues after using ph down in combination with Biobizz fertilizers. So that's why I'm pretty afraid.


Thank you so much guys! I do really love my Babies and I want them to get healthy again ; )

I've used lemon juice as pH adjuster before and works OK.

 

[Paranoidis]

Ok, PH after adding Nutes something between 7.0 and 7.5, after adding 4 drops of lemon juice it drops to 6.5.

Do you guys think I should flush the pots with clear ph-regulated water?

I uploaded a pic of a leave on which the problem seems to start, too.
(Necrotic spots)

 

[Waira]

hey bud! No, on the flushing, never with organic nutes,... Biobizz is very mild stuff, and you plants are big so demand is high,.. I see P defc. mostly, maybe K, and Ca too,... get Ca-Mg in there full strength, ditto for bloom! Water looks OK,....

 

[Paranoidis]

Hey Waira, thx for your advise!
So this meanķs I gave too little of the bloom fertilizer? Should I give my Babies a higher dose of bio bloom per liter? I'll check out how to increase ca/mg concentration

Thank you!
Btw today I measured their height... 182 cm and the other is 186cm high