Nutrient / ph issue in supersoil ?

Hi guys,

Im growing 4 plants in 20 gallon ( US gallons ) pots.
They are in there 3rd week of flower now and everything has been going well apart from 1 of the 4 plants showing problems.

I started these 4 plants from seed in bio bizzlight mix soil for the first 3 weeks of seedling stage in 2L pots.
I then transplanted straight into final pots which were the 20 gallon pots of super soil.
I then vegged them for a further 6 weeks of veg and then flipped to flower 3 weeks ago.
Everything has been going great and the plants love the soil.
Watering has been fine and started off slowly buidling up the amount i watered from early veg up until now. Im giving them approx 10 - 15% water to pot volume, so roughly 7.75L to 10.5L. The plants went from not needing watering for 7 - 9 days in early to mid veg, to every 5 days late veg and in flower, are now drinking the water up within 3 days.
I personally like to do a wet / almost dry cycle as i feel it benefits the plants most.

My conditions have been dialled in from keeping temps throughout the grow at roughly 25•c / 70% RH bottom of canopy and 27 •c / 65% top of canopy throughout veg and up until now.
When the buds start to develop more, i will slowly decrease the humidity levels and temps slightly, week by week.

The soil ive been using is dr organics living soil based in the uk.
The lights im using are the lumatek zeus pro 600w pro 2.7 ( sister company in the us and canada are called photontek )
I noticed that the one plant in the front right, showed signs of stress when i recently raised the dimmer on my lights to 75% power ( 450w ) but the other plants have taken to it really well and are thriving.
All plants are same strain, sugar bomb punch from dutch passion.

If anyone can give me any advice or help on what they think the problem is, i would be ever so grateful.

I will post pictures of my plants from seedling through veg and now flower with a few pictures over the past few months to show progression.

1st pic was couple of days after germination.
2nd pic was 3 weeks into seedling.
3rd pic was transplant into final pot and start of veg.
4th pic was about 3 weeks into veg.
5th pic was end of 6 week veg / switch to 12/12 flower.
6th pic was about nearly 2 weeks into flower.
7th pic was friday just gone, i raised the lights higher above canopy and turned up to 75% power.
The other pics just show how the plant at the front right is showing yellowing and burnt tips on some of the leaves, yet the other 3 plants are thriving !
All plants have been fed using molasses, worm castings and had first top dress of bloom amendments on friday, only mixed at 2grams per litre of soil, so roughly 160g top dress in each. Didnt need to feed through veg as there was enough in the soil and didnt want to over do it.
I do apologise in advanced for the huge message.
Any feedback would be much appreciated,
Cheers

What do you mean by "bloom amendments?" The ones you used the day you turned up the light?

I can see why you suspect pH, but I'm not convinced. I suspect different phenotypes giving you trouble.

Plants look good. Front-right plant has been lighter green for some time, and is stacking bracts more slowly. Not sure if that's just genetic expression or a sign of imbalance. Again, I suspect phenotype variation, as the plant looks large and healthy.

Thanks for getting back to me mate.
The bloom amendments are dry amendments for use in flower / bloom.
The ratio of npk for it is 2.8.10.
Ive not had to feed them up until now because the pot size has carried them through veg and first couple weeks of flower.
i topped dressed with 2 cups worm castings and some bloom amendments just incase they start to get hungry, as im aware that top dressing takes a while to release nutrients.
I agree with what you say in regards to the plants phenotype too potentially.
Would you just give plain water for the next few waterings, or do you think id be ok to still add molasses to the water ?
Ive read a few forums and some people say that excessive use of molasses can effect ph of soil but not sure whether thats entirely true.

I haven't used molasses. Can't say.

If the issue progresses, I might try raising the light a bit more. Other than that, I hesitate to say much. Seems like you give a lot to the plants and they're kinda big, so I wouldn't want to throw off the balance.

GenericEnigma said:

I haven't used molasses. Can't say.

If the issue progresses, I might try raising the light a bit more. Other than that, I hesitate to say much. Seems like you give a lot to the plants and they're kinda big, so I wouldn't want to throw off the balance.

Click to expand...

thanks for the feedback mate

2-8-10 dr forest by any chance? They look healthy and would hang fire adding late bloom amendments for a wk or so . Looking good good luck for the rest of your run op

Leeski said:

2-8-10 dr forest by any chance? They look healthy and would hang fire adding late bloom amendments for a wk or so . Looking good good luck for the rest of your run op

Click to expand...

Thanks mate.
No its dr organics living soil dry amendments mate.
I was going to get the dr forest before though. I thinj they’re pretty much the same thing to be honest.
Yes i will hang fire with another top dress now for sure. I was going to risk running the plants without a top dress throughout the whole grow to be honest, as i felt the pots were big enough to get through.
all the plants are showing some tip burn but nothing major. The yellowish plant seems to be greening up abit now after just giving water.
I know they say you dont need to ph with living soil but i still like to get it at roughly 6.5 with citric acid ph down. I think i will put some aloe vera powder in the water for my next watering as ive heard good things about it.

Hi guys,

its been almost 2 weeks since my last post.
The plant i was concerned about in front right has greened right up and looks alot better.
it was stressed from something ans i believe it may have been the dr organics microben terra actus molasses as it suggested to use 20ml per litre of water so ended up mixing 160ml and ended up giving 12L water each so maybe it was too much molasses or too much water at once.
That plant is about a week behind the rest from the stress but has recovered well.
in coming to the end of week 5 and i know its normal to lose leaves at bottom of canopy but theres spotting, browing, yellowing and red stemming going on and just wondering if anyone can help diagnose the problem.
I last top dressed them with 160ml of bloom amendments 2.8.10 bloom in 20 gallon / 75L ( US gallon ) pots.
I have 4 weeks left so dont know whether its deficient or whether its a toxicity of some sort or possibly over watering.
Im suspecting a possible K or P deficiency but any further advice would be highly appreciated.
Thanks guys

Lnp32 said:

Hi guys,

its been almost 2 weeks since my last post.
The plant i was concerned about in front right has greened right up and looks alot better.
it was stressed from something ans i believe it may have been the dr organics microben terra actus molasses as it suggested to use 20ml per litre of water so ended up mixing 160ml and ended up giving 12L water each so maybe it was too much molasses or too much water at once.
That plant is about a week behind the rest from the stress but has recovered well.
in coming to the end of week 5 and i know its normal to lose leaves at bottom of canopy but theres spotting, browing, yellowing and red stemming going on and just wondering if anyone can help diagnose the problem.
I last top dressed them with 160ml of bloom amendments 2.8.10 bloom in 20 gallon / 75L ( US gallon ) pots.
I have 4 weeks left so dont know whether its deficient or whether its a toxicity of some sort or possibly over watering.
Im suspecting a possible K or P deficiency but any further advice would be highly appreciated.
Thanks guys

Click to expand...

Looking nice with a bit of a phosphorus deficiency, most likely. If it were me, I'd add some.

Probably more than four weeks left, though.

GenericEnigma said:

Looking nice with a bit of a phosphorus deficiency, most likely. If it were me, I'd add some.

Probably more than four weeks left, though.

Click to expand...

Thanks for feedback mate.
I only top dressed them last week though.
would i be ok to top dress them this late into flower ( im half way through week 5 / day 33 )
I also gave them 1L of worm castings each too.
Maybe they are just heavy feeders.
Well i will do what you recommend and top dress some 2.8.10 bloom and maybe only give them half the recommended dose just to see how they get on and i’ll water it in with some molasses.
Fingers crossed as i still have a month left to go yet and dont want them burning out on me.

Coming to think of it, do you think id be better off making a tea with some worm castings and bloom amendments watered in with molasses as opposed to top dressing for quicker response ?

If you top dressed last week then I'd hold off on another top dressing. Give the amendments time to reach the root zone. Giving the plants a tea is never a bad idea in my opinion. I've had to do that in the past to keep the plants stable, while waiting for the amendments to do their thing.
Good Luck.

Syntax747 said:

If you top dressed last week then I'd hold off on another top dressing. Give the amendments time to reach the root zone. Giving the plants a tea is never a bad idea in my opinion. I've had to do that in the past to keep the plants stable, while waiting for the amendments to do their thing.
Good Luck.

Click to expand...

thanks for the info
is there a certain dosage you’d recommend i give ?
on the tub of dry amendments it recommends 2ml per litre of soil and im in 75L pots so do you think 150ml of bloom amendments will be toostrong for a tea ? Should i half it ?

Lnp32 said:

thanks for the info
is there a certain dosage you’d recommend i give ?
on the tub of dry amendments it recommends 2ml per litre of soil and im in 75L pots so do you think 150ml of bloom amendments will be toostrong for a tea ? Should i half it ?

Click to expand...

Is that recommendation for teas or top dressing? I'm not familiar with your bloom amendments, so I can't really give you a recommendation on dosage. Usually if I want to make a tea during flower i will add 1 cup of ewc with another 1/2 cup - 1 cup of something like Bio Fish (Down to earth), then bubble them together with the molasses. Fish Hydroslate works well also, but it smells like ass. In the past I've also let the ewc and bio fish sit in a bowl with Kashi on top for about 3 days so that Bio Fish starts to break down a little before bubbling it. There's no rule book for teas. You will just have to do some research and try to make your best judgement.

Syntax747 said:

Is that recommendation for teas or top dressing? I'm not familiar with your bloom amendments, so I can't really give you a recommendation on dosage. Usually if I want to make a tea during flower i will add 1 cup of ewc with another 1/2 cup - 1 cup of something like Bio Fish (Down to earth), then bubble them together with the molasses. Fish Hydroslate works well also, but it smells like ass. In the past I've also let the ewc and bio fish sit in a bowl with Kashi on top for about 3 days so that Bio Fish starts to break down a little before bubbling it. There's no rule book for teas. You will just have to do some research and try to make your best judgement.

Click to expand...

Thanks for feedback once again.
Well the bloom amendments recommend 2ml per litre of soil and im in 75L pots so i just top dressed 150ml.
I did raise the lights and turned up to 100% and maybe its abit too soon for that intensity until the buds really start swelling so ive turned the light back down to 75% power and lowered it slightly.

today i decided to top dress my plants with 3litre of worm castings in each pot, i mixed 160ml of gypsum and 60ml of epsom salts and mixed it all in together. The reason for this is the one plant is showing signs of calcium deficiency.
Also stems are starting to purple up badly on back left plant.
alot of people on forums ive read say that it takes a good while for gypsum and epsom salts to release nutrients into the soil but thought id give it a try anyway.
Apart from that, everything else looks good.
Im just hoping that i can get to the finish line without fucking up my buds.
Im just about to start week 6 on monday so ive got 3 weeks left roughly

If problems are going to pop up in flower, in my experience they seem to hit between week 5 & 6. Turning the par down on the led seems to help in regards to the plant not having to eat as much, thus slows down the deficiency a bit. Purple stems can be contributed to Phosphorus deficiency. They can also be contributed to genetics, so take it for what it's worth. You will most definitely want to get the phosphorus stable. Phosphorus deficiency will affect yield and ripening times. I can only speak about my own experiences, it's not from some textbook literature, so take from it what you will.

damn jungle in there lol

Just to mention i know you said not to top dress but i added some more bloom amendments but literally only 1/2 the recommended dose.
I had a look at fish mix but it said it was for veg growth. I did find an instant liquid mix high in phosphorus though and its biobizz bloom. Do you think i could hit the soil with that on next watering or will it be too much ?