Rockwool problem def.

What up guys still tryna get a hang of this rockwool game .. anyway every time I feed my plant the bottom leaves seem to shrivel and yellow , put new growth seems fine every watering it the older leaves wilt n yellow plus I can't solve my phosphorus issue ...? So I been feeding at ph 5.8
2ml cal mag / 2ml An sensi grow a&b and a little silica blast for ph up strain is purple punch

Just checked my ph pen it was off by 2 so I was actually putting in 5.6 instead of 5.8 I'll post back to see if this helped

So I've corrected the feeds to 5.9 and ph is calibrated correct .. and the phosphorus lockout seems to be clearing up a bit , but the lower growth seems to shrivel or yellow out as soon as I feed ..? Any input ?

http://www.growweedeasy.com/nitrogen-deficiency-cannabis


I had the same thing with tangie in rockwool. Just fed nitrogen and it cleared up quickly.

for now im just guessing

I think your under feeding across the board
and I betting your nutrient ratios are out

lets get some more info and get you straight!
id been in rockwool forever

the silica is likely also giving you trouble

theres a delicate relationship between potassium, calcium and magnesium

adding silica adds a large amount of k and can easily throw out the balance between these elements
theres also a relationship between K and N which could also be a smaller factor

I need some info on the sensi part a&b
either take a picture of the label of each bottle showing the listed % for each element and post it so I can see it
or clearly tell me what it says in a way that's easy to understand
for example

part A
N.........5%
P.........2%
K..........7%
Ca........2%

and so on

@im4sato I'll check that tomorrow , have no idea lol ... but yeah I was checking run off and it was 6.3-6.4 I flushed it last week and feed 5.8 this am came out 6.0-6.1 so look like ph is getting better . Stalk is clearing up but have some stripping .. trying to dial this in lol ??? Rockwool lil difficult ??? , all my soil plants are killing it !!!!

What EC or ppm are you feeding your plants?

STLbudz said:

@im4sato I'll check that tomorrow , have no idea lol ... but yeah I was checking run off and it was 6.3-6.4 I flushed it last week and feed 5.8 this am came out 6.0-6.1 so look like ph is getting better . Stalk is clearing up but have some stripping .. trying to dial this in lol ??? Rockwool lil difficult ??? , all my soil plants are killing it !!!!

Click to expand...

that small a ph difference isn't an issue

if your anywhere from 5.4 to 6.2 your good

the fact that your ph is rising

5.8 going in and 6.2 going out is a positive thing...as in good..thats what you want

are you running a closed/recirculating reservoir or an open drain to waste system??

what that might tell me is your likely feed an appropriate EC/PPM
you might need to water a little longer duration each time you water
the longer waterings will bring your RW ph samples down a bit

but it doesn't explain a nutrient issues or imbalance
I suspect (since your using silica) you've got in imbalance in the potassium, calcium , magnesium ratios

when you get the nutrient mix balanced the rockwool is easy enough