So.... Lots of problems with my ISS

[waltwalt]

How long has this problem been going on?
2 weeks

What STRAIN are you growing?
Island Sweet Skunk x Blueberry Skunk

What was the establishing technique? (seed or clone?)
Seed

What is the age of your plants?
Seeded 5 weeks ago today.

How long have they been in the soil mixture they are in now?
3 Weeks

How Tall are the plants?
14"-24"

What PHASE (seedling, vegetative or flower) are the plants in?
Vegetative

What Technique are you using? (SOG, SCROG etc)
None

What size pots are you using? (Include how many subjects to pot)
Currently in 3 gallon square pots.

What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?)
Canna Bio Terra Plus

What Nutrient's are you using?
Fox Farm Feeding.

How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
Foxfarm started out at 1/4 strength after 2 weeks and has been ramped up to 80% strength.

How often are you feeding?
Plants are watered every other day, nutrient solution is used every other feeding.

What is the TDS/EC/PPM of your nutrients used?
Unmeasured.

What is the pH of the "RUN-OFF"?
7.2

What method of pH test was administered? Using Strips? pH pen?
pH Pen

How often are you watering?
Every other day.

When was your last feeding and how often are you feeding?
4 days ago they received nutrients, yesterday they received water.

What size bulb are you using?
400W MH

What is the distance to the canopy?
12"-16"

What is your RH Factor? (Relative Humidity)
45-55%

What is the canopy temperature?
75-77F

What is the Day/Night Temp? (Include fluctuation range)
70-77F

What is the current Air Flow? (cfm etc.)
4" Grotek 210cfm fan

Tell us about your ventilation, intake exhaust and when its running and not running ?
Grow hut intake ports open, fan runs 24hrs/day vents into attic.

Is the fan blowing directly at plants?
Oscillates across the plants.

Is the grow substrate constantly wet or moist?
It dries out after about 2 days.

Is your water HARD or SOFT?
Soft (Filtered)

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
Filtered Tap Water that's been bubbled and pH adjusted.

Are you using water from a water softener?
No.

Has plant been recently pruned, cloned or pinched?
Some have.

Have any pest chemicals been used? If so what and when?
No.

Are plant's infected with pest's?
No.


That's that.
My plants are all showing different signs of different problems.

The first pic Burnt shows a plant I believe has been too close to the light, or didn't appreciate going from 6x54w bulbs to a 400w MH.

The second pic Canopy shows most of my plants, as you can see the top leaves are much paler than the ones below.

The third pic NewGrowth shows new growth on the plants (duh) that seems paler than it should be.

The fourth pic Tips shows one of my plants with symptoms that a few different plants show, I'm pretty sure that's just nutrient burn, but who knows.

Looking over my list above, I think my pH runoff is obviously way too high, I actually noticed that two days ago and I have dropped my pH from 6.3 to 6.1 on the water/nutrients being added.

These plants were in 3oz containers for 4 weeks before being transplanted to 3 gallon containers about two weeks ago, I realize these are incredibly stunted due to the late transplant.

I'm not sure if there are any obvious deficiencies (still new to this) I think they are:
a) light burnt
b) nutrient burnt
c) possibly also nutrient (pH?) locked.

Should I give them a full flush and dial back the nutrients abit? Have I completely misdiagnosed this?

TIA
-ww

 

[mexilandrace]

it's normal for the new growth to be a lighter shade till it fills in

I see some nute burn and heat stress issues, I never ever use anything at 80 percent, hell not even 50 percent except for the one big hit I do when I flower.

looking at your soil or whatever, is that coir? like full on coir? I don't keep up with soil names.

If so that's your issue, 7.2 is really high for coco.

Hopefully a coco person will chime in...

 

[waltwalt]

From their website:

"Bio Terra Plus is made up of 100% natural materials and as such can also be used for organic cultivation. Bio Terra Plus is made up of top quality peats which include superior quality white peat. The airy structure of white peat is supplemented with shredded tree bark that has natural anti-fungus properties. Bio Terra Plus has been pre-fertilized with certified, organic ingredients such as bone meal, bat guano and a variety of trace elements from natural sources."

The pH is apparently balanced to 7.0 in the bag. I've only fed it water with pH of 6.3, so the pH runoff of 7.2 was surprising. I know the pH pen is reading properly because I calibrate it every time I use it to mix the water/nutrients.

I have yet to get rid of sick/weak plants and I feed them all the same amount of nutrients. I would say that about 30% of them have curled tips like those pictured and the others are strong and big without curled tips or any other signs of deficiencies other than the heat stress/light burn. Should I dial back the nutrients till the sick/weak ones stop curling their tips? Or just keep feeding them till they die as a method of pruning off weak plants?

 

[myc]

did you water heavily after the transplant?

maybe you should flush them out. there may be buildup or something else in the mix buffering the pH and locking stuff out, try lowering the pH of your flush water to see if you can get the runoff closer to the bottom of the 6.3-6.8 range.

or you can dial down (or turn off) the juice for a bit and continue as normal with just water - but lowering the solution pH to try and bring the runoff readings down.

don't bother calibrating your pH pen that often. if you're not wasting the calibration solution, you're contaminating it.
or is it crap and actually deviating much between uses? if so, are you storing it in an electrode storage solution?

 

[waltwalt]

I calibrate the pen every time I use it because the instructions call for that. When I test the water I previously pH'd to 6.3 and it reads 7.3 I think that means its off. I store it in fresh electrode solution everytime I put it away.

I thoroughly moistened the medium after transplanting, it dried out over the period of a week and after that re-watered every time it felt light enough to require it.