Possible Nitrogen N or Magnesium Mg deficiency? Yellow leaves...

Hey all, hows it going everyone. Need some assistance with this grow.

They are having problems with lower and low middle leaves turning yellow. Old growth only.

They have been in FFOF for about 3 weeks, but they have been yellowing as soon as 10 days after transplant into OF. I had originally only been giving them Big Bloom at 1/2 strength with every watering, but later I read that RO water may need Cal Mag despite FFOF supposedly having it in there already. I have been giving 1ml/L GH Calimagic since the 20th of last month as recommended on the bottle. They have all received 3 waterings at this strength. The last watering included 1.75ml/L Pure Blend Pro Grow 3-2-4 on all my plants and the largest plant that is 5 days older received 3.5ml/L PBP. That plant showed what I thought to be signs of nute burn (yellowing of the tips and pointy edge things on the blades of the leaf) so I flushed with water.

I just got a pH meter last week and the pH runoff is showing a little low, around 6.1 or 6.2, and the nute solution I had fed with was way low, around 4 (and water started off at 6.3 before adding nutes) but that shouldn't matter if the runoff is above 6 right? Regardless I am now pH correcting everything I give them, last watering was CalMag only, pH adjusted to 7.1 to counteract the previous low pH feedings.

Don't know if this is a Mg or N deficiency as they both look the same to me and I have yet to see any high res comparison pics side by side.


My questions are as follows:

1) If its an N def then it must be a lockout issue right? (since they showed signs of nute burn when I gave more N; and since FFOF should not be N def. after less than 2 weeks)

2) Also I thought a pH of around 6.1 shouldn't necessarily be that bad and shouldn't cause lockouts...

3) If its a Mg deficiency then how long does it take to correct that? Is the 1ml/L enough or should I be using more?

And of course if its some other issue that I'm missing entirely please don't hesitate to tell me.

I really appreciate the help! Thanks in advance!





Pic #1 here is the one that's a week older that got slightly burned.
These next 8 are all the most recent:









These were when the first signs of yellowing was noticed on 9/17

And the first time I noticed yellowing between veins on 9/19




The full feeding record is as folows:

8/18 - Germ papertowel after soak 24H distilled water
8/20 - Plant in Lightwarrior in 9oz clear plastic cups
8/30 - 1/4 str FFBB
9/06 - 1.875 ml/L PBPg, 3.9 ml/L FFBB
9/10 - transplant to 1/2 gal FFOF 3:1 perlite
9/14 - water with 3.9 ml/L FFBB
9/17 - water with 3.9 ml/L FFBB
9/20 - water all with 1ml/L CaliMagic
9/26 - wilted due to underwater, water with 1mL/L CaMg, 7.5ml/L BB, 1.75ml/L PBPg,
one plant with double strength (3.5 ml/L PBPg) showed signs of burn
10/01 - water with CaMg 1.5ml/L, pH adjusted to 7.1

*one plant is a week older, but the rest of the plants were born on 8/18


Questionnaire:

How long has this problem been going on?
Happens on all plants after they reach a certain age.
What strain are you growing?
WW
What was the establishing technique? (seed or clone?)
Seed
What is the age of your plants?
Planted germd sprouts on 8/20, transplanted to FFOF on 9/10
How long have they been in the soil mixture they are in now?
since 9/10
Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before?
Germinated in lightwarrior. Might have kept them in there for a little too long and stunted them but when they went into OF they took off.
How Tall are the plants?
6-7 in maybe
What PHASE are the plants in?
veg
What size pots are you using? (Include how many subjects to pot)
approx 1/2 gal
What substrate/medium are you using?
FFOF 3:1 with perlite
What brand Nutrient's are you using?
GH Calimagic, FF BigBloom, Botanicare PBP Grow
How much of each nutrient are you using with how much water?
see above
How often are you feeding?
no set regiment yet, trying to feel them out and correct this deficiency
What order are you mixing your nutrients?
calimagic > bigbloom > PBP
What is the TDS/EC/PPM of your nutrients used?
dunno
What is the pH of the "RUN-OFF"?
around 6.1, tested with electronic tester
How often are you testing pH/ppm/EC/TDS?
every time I feed now
How often are you watering?
~ every 4 days, when they get dry
When was your last feeding and how often are you feeding?
see above
What size bulb are you using?
8x 23W CFL 5000k and 6500k
How old is your bulbs?
new
What is the distance to the canopy?
3"
What is your RH Factor? (Relative Humidity)
between 50-75%
What is the canopy temperature?
70-80F
What is the current Air Flow? (cfm etc.)
6" fan blowing across plants
Is the grow substrate constantly wet or moist?
No
What water are you using?
RO (walmart drinking water in 1g jugs)
If using RO,Distilled,mineral water, what is the ppm/EC/TDS without any additives?
5ppm
Are plant's infected with pest's?
No, killed maybe 5 gnats over the last month

Looks like nitrogen is required.

Yup needs a feed

For what its worth i agree that it is most likely nitrogen def

The yellowing of bottom leaves is normal - no worries -no toxicity (nutrients) if anything could be nutrient "splash" when watering plant. If "N" toxicity leaves will look like claws and be a dark green color. This is the only leaf of all plants? if so you have no deficiencies either. flush for one week to fix issues. Taking another look at picture "you have "n" toxicity good you caught it early -flush for one week and re-adjust nutrients, always watch you "n" use easy to over do it. Remember once you see deficiency you are 2 weeks behind in fixing it-- thing swill be just fine

So you are saying that just because it burned doesn't mean anything because burn can show up quickly but deficiency can take 2 weeks?

But how do I have N deficiency if they are in Ocean Forest plus the additional veg nutes? I was told OF by itself was supposed to have enough N-P-K for 3 to 4 weeks, they are yellowing after not even 2 weeks... (That's why I was thinking Mg or lockout)


Thanks everyone for your help!

pornstache said:

So you are saying that just because it burned doesn't mean anything because burn can show up quickly but deficiency can take 2 weeks?

But how do I have N deficiency if they are in Ocean Forest plus the additional veg nutes? I was told OF by itself was supposed to have enough N-P-K for 3 to 4 weeks, they are yellowing after not even 2 weeks... (That's why I was thinking Mg or lockout)


Thanks everyone for your help!

Click to expand...

Looks like Ocean Forrest problems to me. Heres what ive found, FFOF takes me al the way to flower( 6-8 week veg) with calmg only. then i suppliment as needed. that stuff is packed full NPK and when i was feeding regulary with ocean forrest had same problems. could be lockout due to many different reason. but pumping more nutes is not going to help. just keep them on CALMG and water only phed and should be good. If anything during veg i use the guano companies super tea with microbe brew.