Rockwool Pros???? Deficiency week 2 of flower??

Ok so I'm banging my head up against the wall... ive tried what I feel like is everything

higher ec, lower ec, higher ph, lower ph, ramping the lights up slower when moving to flower

basically I'm growing in rockwool 6x6x6 blocks, when i move the plants to flower i put them on unislabs

ec in veg is 1.4
ec in flower is 1.8

ec in blocks is 2-6 with my grosens meter





any idea why every time i put my plants in flower around week 2 they start yellowing out prematurely, then I get leaf necrosis and dropping?

I'm feeding every hours for a 1m20s with 2 (2gph drippers)

and the plants are so large i need to give them 3 night irrigations or they will dry back to 7% or so which obv isnt good....

what do you guys think?

I use HGV nutrients, on a dosatron system

I recently started using UC Roots in the system hoping if it was a root rot issue itd help (which i dont think it is)

I'm using RO well water

I've also tried more frequent irrigations... seems like every hours is pretty good for the charts though



WHY THE HELL ARE THE PLANTS ALWAYS SHOWING DEFICIENCY STARTING WEEK 2 OF FLOWER?!

its not a nutrient salt buildup since theres plenty of runoff... in the room pictured i gave it veg nutrients the first two weeks of flower to see if that'd help and they seemed to take off a bit quicker but in the past they got flower nutrients right when they went in the flower room


help me guys... my home grow looked fucking perfect, not my commercial spot is struggling to get dialed in

If your recirculating the nutes, this might help.

Your way more advanced then me buy the looks of it, but could it be a magnesium deficiency?

this is all drain to waste, so the nutrients are fresh pulled from the dosatron every irrigation cycle...

my nutrients are two part. part 1 is CalNit (calcium nitrate) part 2 is either HVG Growth or HGV Flower...

I'm leaning towards these being root bound and trying a few plants in 5 gallon pots of gro-cubes

fingers crossed this will help

anyone chime in, yay or nay?

Your EC in the blocks is 2-6? Is that a typo?

Maybe try running less EC in veg and feeding more often.
Not my cup of tea rockwool. not sure what the benefit is of running a dtw with it over coco, but that's me.

Salt build up springs to mind.

I think @ANC is experienced in rockwool, maybe he has better advice.

They are not being fed enough that big of a plant with that small of a root space you would need to almost feed them constantly

I have 25 gallon pots and I have to feed every two hours for 30 min and four hours at lights out at 750 early flower never past 950 at peek or I get deficiency issues bump up that feeding big time

2gph? on a biggie block sitting on a uni? fuck, that sounds like not enough Nutes are getting thru to flush out the used up solution in the block&slab.
How much run off are you getting from each block?

Bump up the Calmag, Your plants look to be eating that faster then the rest of the elements.

I can tell you that it's not a root bound problem because I'm running 3-4 foot plants in 4 inch blocks without any issues.

What are your temperatures like.

Show us pics of the roots and cubes.

temps are like 75* rh is at 50%

i think it is a root bound thing... ive tried lower ec, tried higher ec...

i noticed yesterday several of the cubes had irrigation solution running off them... its like the top of the 6x6x6 are a solid mass of roots... i have to get the drip stake and punch it in around the block like im aerating a lawn... and ususally theres almost no where i can put the stake back into since its so full of roots...

even if its not directly linked to the root bound im wondering if theres pockets of higher ec in where the roots seal off spots from being so tightly packed in there... or just that its causing the irrigation to not be able to flow through the blocks properly...

these plants are huge... some are over 7' tall and some span out 6+ feet. it also seems like its always the larger plants that show these signs the most

and I'm getting plenty of runoff... irrigating based on the shot size... the recommend 3-6% shot size (of block volume) ive been all over the board.... too much, too little...

now im around a 5% shot size in flower feeding every hr (but ive tried way more feedings even up to every 20 min) same results

Last thing to do is test the run off pH and PPM.

Maybe take a slice of the outer plastic off and see what the roots look like under the plastic. That will really say if it is rootbound.

You are currently in unislabs, are those the large rectangular Rockwool blocks?

yeah but not too large like 10x8x4

Slimjimham said:

temps are like 75* rh is at 50%

i think it is a root bound thing... ive tried lower ec, tried higher ec...

i noticed yesterday several of the cubes had irrigation solution running off them... its like the top of the 6x6x6 are a solid mass of roots... i have to get the drip stake and punch it in around the block like im aerating a lawn... and ususally theres almost no where i can put the stake back into since its so full of roots...

even if its not directly linked to the root bound im wondering if theres pockets of higher ec in where the roots seal off spots from being so tightly packed in there... or just that its causing the irrigation to not be able to flow through the blocks properly...

these plants are huge... some are over 7' tall and some span out 6+ feet. it also seems like its always the larger plants that show these signs the most

Click to expand...

Have you tried to just feed them constantly? or at least a lot more like 1min 20 s every 10 min and for how long..... could take many days to correct

Ok the first image, I can see that your yellow sticky tapes are fully loaded, with what I bet are fungus gnats? These bugs cause problems.

A few purple stems on the last images, maybe bump up the temp a degree and try for more humidity as well.

Root bound in rockwool is kind of a myth

Are you positive those are just fungus gnats on your sticky traps?

I'd scope them to be sure its not RAs. Not trying to cause a panic but you said you already tried everything and what you're describing sounds eerily familiar to the war stories I've read from other members battling those bastards.

Tangerine_ said:

Are you positive those are just fungus gnats on your sticky traps?

I'd scope them to be sure its not RAs. Not trying to cause a panic but you said you already tried everything and what you're describing sounds eerily familiar to the war stories I've read from other members battling those bastards.

Click to expand...

RA?

Root aphids

ToFarGone said:

RA?

Click to expand...

Root Aphids. Cockroaches of the cannabis world.
Plants typically present as Mag deficient and many times, its not noticed by the grower until the first couple wks of flower.
Again, I do NOT want to cause panic for Slim. Just think he should scope to be certain.
I'd just read a thread a few weeks ago on ICMag where a member opened a slab of rockwool and found RAs crawling around. Hydro shops can be filthy.