Leaves are turning yellow...

[GrumpyOldMan]

Ok, Help...As you can see, I've got something wrong with my plants, Here's what I've got;
3 LA Peyote Kush fems, 2 in Mother Earth CoCo, 1 in Fox Farm Ocean Forest soil , the coco/soil has 1/3 Perlite added to it.
I'm using Fox Farm Hydroponic Food trio for the coco plants, and I'm using the Fox Farm SOIL trio for the 1 soil plant.

Heeding the advice of the forum, I'm only feeding the Coco plants 1/2 strength food mix right now (PH adjusted to 6.0+/- AFTER adding nutes)
Also, heeding the advice of the forum, since the soil is "preloaded" with about 30 days of nutes, I'm only WATERING the SOIL plant - NO NUTES YET, just PH adjusted water (6.0+/-)

The soil plant (the pic with my hand in it) was the first one to show any signs, and it's been about a week now. the other one started about 2 days ago.

But what's odd is the middle plant shows no signs of this and EVERYTHING is the same between the two coco plants.

They get fed just about every other day, I keep detailed records of the temp/RH in the tent, when, what, and how much they're fed, etc.
Right now they're getting about 40 oz of food/water every feeding - with about 2 -3 oz runoff

Temp/RH runs in the upper 70' to low 80's, RH in the low to mid 40's, Lights on 100%,18/6, about 26 " above the plants, all per the light instructions.

Thought about Nute burn, but not sure about why soil plant just now started having problems, and only gets water.

Any Ideas?
Thanks,
GrumpyOldMan

[dilvish]

recalibrate the PH tester and make sure in coir it's 5.5 -6.5 and soil from 6.0 - 7.0 this is with the nutes mixed in. PH being incorrect can cause all kinds of problems. You may also be overwatering.

[GrumpyOldMan]

I keep close watch on the coco food PH, I usually keep it at or near 6.04 - 6.08,
so from what you're telling me, I SHOULD be OK on the PH.

But what confuses me is that the soil plant just gets water...


As far as watering goes, I usually wait until it's dry down to 1", but I have been feeding it about 40 oz ...
maybe let it get a little drier?

Thanks,

[Gingerbeard]

You didn't mention Cal-Mag, GOMan. Are you using any? I'm in my first coco grow and my first coco issue was lack of Cal-Mag.

[homegrown]

As Gingerbeard suggested, are you adding cal-mag to each water? I've been using coco for the last 9 or 10 grows and always add cal-mag to every water. Also, i have found that 6.2ph is my plants happy place..i may fluctuate up 1 or 2 points but i try to stay at or just above 6.2.

[GrumpyOldMan]

Hi, And yes, I'm using Cal-Mag as well with every feeding, but what REALLY has me stumped is why is my SOIL plant developing yellow leaves when all I give it is PH adjusted water? (6.04 - 6.08)

[Bowhunterwoody]

I don't usually chime in but 6.04-6.08 is pretty low for soil. Especially FFOF. Ca and Mg have a hard time being absorbed.

[Puglover1]

In a 'hot' soil I used 6.5 - 6.8 pH water, higher than in coco.

[Going2fast]

Did those leaves at any time touch the damp soil?. If I let leaves lay on the soil for a few days they will die back.

[GrumpyOldMan]

Going2fast, I had a couple do that, and I'm not 100% sure that's not what happened to the soil plant leaves, because the affected leaves ARE on bottom, so...
BUT, the leaves on the coco plant are on top, and never touched the coco.

[GrumpyOldMan]

Bowhunterwoody, since I'm new to this, I'll take any advice given, what would you recommend the soil water PH be, I read where homegrown said he keeps his about 6.2
Like I said, right now the soil plant gets nothing but PH adjusted water.
Thanks

[Bowhunterwoody]

I just got thru a run with all kinds of pH problems. I was running at 6.3-6.4 with FFOF and it tanked at week 5. Might have been a bad batch of soil but more likely over watering early causing root problems. Next time I'll try to keep it at 6.5 or 6.6 and watch the runoff.

[Ckbrew]

Looks like Ph and/or calmag deficiency. What are you using to measure Ph? If a pen, what are you using for calibration and how often? I do a quick calibration check before every time I use the Ph pen. Those dam things have thrown off so many grows due to calibration issues. You think you are on top of it, but if the measuring device is off, your calculations for Ph are out the window. If you have Ph paper, do a spot check to see if it matches the pen. I usually add calmag at 2.5ml/gallon at a minimum, it is hard to over do calmag. You have 2 different mediums going, but the same problem occurring. The Ph is the most obvious common denominator. Have you done a bug check? I don't think it is, but worth a check.

[GrumpyOldMan]

When you say you'll watch the runoff, are you talking about quantity or PH or both?

[Bowhunterwoody]

pH. I try to keep run off to a minimum for the first month or so. Don't want to wash out the nutes that FFOF has. Then about 10-15% runoff after that.

[GrumpyOldMan]

I meant this last post for bowhunterwoody, sorry

[GrumpyOldMan]

CKbrew, I use a Viviosun pen, I've had pretty good results with it, calibrated it a few days ago. As far as the cal-mag, I use the same thing as you, 2.5 ml/gal.
Like I told bowhunterwoody, I'll gladly take any advice. Would you think the water for the soil is too low? (right at 6.04 +)

[Ckbrew]

These are from GWE, search Ph. I don't grow in soil so my response is more toward the coco. That said, looking at the chart, yes I think 6.04 is to low for soil. The chart says you are missing calcium and possibly phosphorus uptake. But remember, if your pen is off, all bets are off. I have the same pen. I don't trust it any farther than the inverse of the distance of how far I can throw it. I check it with the 6.86 calibration solution every time before I use it.

[GrumpyOldMan]

CKBrew, I've seen these charts, and I can see where I would want my Coco food up more, the calcium is at the low end...but the phosphorus is at the upper end, so maybe 6.15 +?
In reference to the pen, I assume(?) that you mix up the calibration solution every time? Is this something that can be stored once it's mixed?
And lastly, I've thought about getting PH test strips, just as a back up/check, so I guess I'll be looking into that?

Thanks again