plant diagnosis too much N cauing small leafy bud and black leaves???

[blazeinhard]

hi all on day 56 and one of my plants isnt doing too well, it has very leafy buds and i go to touch them and theres no density to them there just like sponge and the majorty of the colas are just leaf, strain is cookies kush(barneys) , not sure if its genetics or what but the critical kush i have next to it has big hard dense buds and they been in the exact same conditions, could it be from too much nitrogen maybe that pheno type reacted badly or someting, also some leaves are going black which is very odd never had this before it a deficiency or somthing, i dont know what todo about leafy buds maybe let them go for another 3 weeks an hope they get dense, any help is appreciated. also in canna coco using a+b nutes

 

[Cobnobuler]

Its really hard to properly see the shit under that HPS lighting. Try taking some pics without that and it can be seen much better.

 

[shushubandora]

try bit of higher ph, 6.5-7 for awhile and see if its works better

 

[blazeinhard]

ill try taking a pic just before lights come on i dont like to disturb my ladies sleeping, and ph 6.7-7? im in coco wont this cause a nute lock out? i normally ph to 5.8

 

[toomp]

Is p getting locked out?

 

[DirtyMcCurdy]

Yeah, I've seen suggestions from others who use coco saying go as low as 5.2 and up to 5.8, topping out at maybe 6.0? I've go into the 5.3's when I batch a fresh reservoir because I know it will slowly drift up anyways. I've noticed no ill-effects from going that low.

ill try taking a pic just before lights come on i dont like to disturb my ladies sleeping, and ph 6.7-7? im in coco wont this cause a nute lock out? i normally ph to 5.8

 

[blazeinhard]

some og the leaves seem to be purply and black an its seems to be spreading, i gave it a half dose of a and b and woth some extra pk hoping she will put on some density as there is really no density to the buds at all at the moment not what i was hoping for :/ might be a very low yeilder

 

[shushubandora]

why do you go so low with the pH?

looking at the availability chart, at high acididty most of the phosphorus will become dihydrogen phosphate and will not be available to the plant (at PH 6 almost 95% is already dihydrogen phosphate)
and I don't see any increase of the other elements bellow pH 6...

there is a decrease in Iron, Mg etc If the pH is high
but even at pH 7 the availability is still there

in my short experience the only time I got black leaves was when I go to pH < 5.5

today I grow hydroponic and I target anywhere between 6-7 (In washing I use water as is, pH ~

 

[DirtyMcCurdy]

why do you go so low with the pH?

looking at the availability chart, at high acididty most of the phosphorus will become dihydrogen phosphate and will not be available to the plant (at PH 6 almost 95% is already dihydrogen phosphate)
and I don't see any increase of the other elements bellow pH 6...

there is a decrease in Iron, Mg etc If the pH is high
but even at pH 7 the availability is still there

in my short experience the only time I got black leaves was when I go to pH < 5.5

today I grow hydroponic and I target anywhere between 6-7 (In washing I use water as is, pH ~

I pH that low because the nutes I use contain nitrate nitrogen. Plants uptake the nitrates first, whether they need them or not. So, as they do this the pH slowly drifts up in my reservoir. This may very depending on what nutes you are using however. Thats why I start low, so I can drift upwards through the pH range.

 

[Farmer's Hat]

The plant will take up P before N during the flower cycle. It has very little use for N at this point.

The fluffy nugs is most likely genetic. Even with very little levels of P, a flowering plant with good genetics will still produce nice beefy nugs.

 

[DirtyMcCurdy]

It will take up nitrates whether or not it "needs" it. Thats why you cut back the N in flower, but you still need some. If you don't cut back the nitrates, you end up with really dark leaves, just more leaves in general and usually end up with leafy buds. Because, like I said, it will uptake nitrates whether or not it needs them. This also waste energy as nitrates take quite a bit of enegy for the plant to assimilate, so no, you don't want this in flower but yet you still need a little.

 

[blazeinhard]

thinking it could be genetics and possible too much N, ive been watering the same as a plant next to it which has big dense buds so really not sure also feed with canna a and b so confused as to how i could of over done the N as it has an NPK of 5-4-3

 

[shushubandora]

I pH that low because the nutes I use contain nitrate nitrogen. Plants uptake the nitrates first, whether they need them or not. So, as they do this the pH slowly drifts up in my reservoir. This may very depending on what nutes you are using however. Thats why I start low, so I can drift upwards through the pH range.

if you use RO water, then pH is sensitive.
but you can create buffer, I use silica.
after I add 1/20 spoon of silica for 10 liter of water, I need to add 1.5ml of phosphoric acid.
without silica 3 drops (0.3ml) of phosphoric is enough to take my water to pH 6

with the silica and the acid, my pH is less sensitive (I guess increasing the amount of water will do as well)