Deficiency or nitrogen toxicity or what?

8 weeks from sprout and I’m lost as to what to do here. These are autos grown in fabric pots a layered soil bottom third FFOF plus perlite, myco, EWC and Dr earth and top 2/3 is FFHF plus perlite. Three are in 3g and three in 5g pots. My issues started around week 5 and has progressively gotten worse.

Running a mars hydro tsl2000 in a 4x2 and a mars hydro ts1000 in a 2.3x2.3. Using the photone app and lights adjusted to 40dli at canopy top. Temps are on average 74-75* and RH 55%. Each tent has an oscillating fan that blows on the canopy tops at speed 3 of 10.

I water every other day with ~1.25 liters of ph adjusted tap water 6.2-6.5. My tap is ~250ppm. Measuring with an Apera PH20 and EC20 pens that were calibrated at the beginning of this grow. When I water the pots are light and the 1.25 liters gives just a little bit of runoff.

At week 6 I amended with recipe 420 ultra bloom dry ferts and top dressed with a couple cups of FFOF soil. Top dressed again with FFOF soil yesterday. I have also given them 2 feeds of calmag.

One plant looks worse than the others but it’s not the entire plant. Some sections look great and others are super yellowed. This plant is one of the larger and is in a 3g pot.

Any help, ideas, things for me to do check etc. are greatly appreciated. I’m a few weeks away from finish and want to do As much as possible to push them across the line!

Here is plant #2 and is in a 5g pot. Again, the entire plant doesn’t look horrible, just certain sections, primarily the older growth looks to have an issue.

Plants #5 and #6 that are together in the 2.3x2.3. These don’t look too bad and are both in 5g pots. Frustrating how some look ok and others are struggling.

So I recalibrated my ph meter this evening and mother fucker it had been reading my tap at 8.2 but after recalibrating it now reads 7.0. I’ve been adjusting down to 6.2-6.5 but if the meter was off by 1.2 then actual ph would’ve been around 5.0-5.3.

I decided to run a gallon of 6.5 ph water through the worse looking plant and test runoff. The plant was surprisingly dry even though I gave her 1.25 liters yesterday evening. I got a little less than a half liter of runoff. Ph was 6.5. ec was 2.55 us/ms which on a 500 scale converts to 1275ppm. My tap water is 250ppm.

All this leads me to think I’ve locked these out due to low ph?!?

Any thoughts? And if yes, how do I fix it in the short term? Long term is to obviously water with appropriate ph.

I think a lot of your problems will resolve themselves after calibrating your ph pen,
She looks a little heavy on the nitrogen but not a huge deal.

s4cruiser said:

So I recalibrated my ph meter this evening and mother fucker it had been reading my tap at 8.2 but after recalibrating it now reads 7.0. I’ve been adjusting down to 6.2-6.5 but if the meter was off by 1.2 then actual ph would’ve been around 5.0-5.3.

I decided to run a gallon of 6.5 ph water through the worse looking plant and test runoff. The plant was surprisingly dry even though I gave her 1.25 liters yesterday evening. I got a little less than a half liter of runoff. Ph was 6.5. ec was 2.55 us/ms which on a 500 scale converts to 1275ppm. My tap water is 250ppm.

All this leads me to think I’ve locked these out due to low ph?!?

Any thoughts? And if yes, how do I fix it in the short term? Long term is to obviously water with appropriate ph.

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PH pen issues are common, make sure to rinse after every use and store with the fluid in the lid appropriately. TBH I've had such issues I just buy a bottle of fresh calibration and check it every week. Rather check it too often than not enough. If you leave it covered in nutrient solution in a warm location it can grow mold.

sandman83 said:

PH pen issues are common, make sure to rinse after every use and store with the fluid in the lid appropriately. TBH I've had such issues I just buy a bottle of fresh calibration and check it every week. Rather check it too often than not enough. If you leave it covered in nutrient solution in a warm location it can grow mold.

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Definitely a reality check.Rinsed and dried and stored in their solution…it still lost calibration over an eight week period.

Unfortunately these plants continue to look worse daily. Not so sure what to do and beginning to get a bit frustrated. This pant had only a few yellowed leaves a week ago and now it is covered. Calcium deficiency? Are they starving and need a shot of liquid nutes? At a loss currently.

s4cruiser said:

Definitely a reality check.Rinsed and dried and stored in their solution…it still lost calibration over an eight week period.

Unfortunately these plants continue to look worse daily. Not so sure what to do and beginning to get a bit frustrated. This pant had only a few yellowed leaves a week ago and now it is covered. Calcium deficiency? Are they starving and need a shot of liquid nutes? At a loss currently.

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No need to PH your tap water in soil. Soil ph low end is 6.5 so I would just run your tap and not even check PH. The damage is done and the leafs that have damage won’t fix them selves so you have to watch new growth but during flower it’s harder because there isn’t much new growth so just try to get them to the finish line. That’s my opinion anyway.
I have some going now that were in coco so they were getting PH of 5.8-6.0 and I transplanted into 7gal buckets of FFOF soil and they show PH issues after first watering but they will turn around in a short time since they are still vegging.
Good luck