new growth yellow - everythung else good

Growing outdoor 15gallon fabric pots
Plants are growing nicely.
There's one out of 10 that has yellow new growth.
Rest of the plant looks good.

It does so happen to be the tallest one.

I've tried researching here and most day it's iron deficiency? Never had that before

But why just one plant? Wouldn't they all be yellowing using the same water and nutrient source?

Here's a chart I like https://www.rollitup.org/t/bright-agrotech-nutrient-deficiency-chart.1052024/
I know Cervantes says in his grow bible that yellowing from an iron deficiency starts from the petiole (stem) and moves toward the tips. I don't see that in the pic but that might not rule it out. Any idea of the PH of the liquid inputs or the soil?

MustGro said:

Here's a chart I like https://www.rollitup.org/t/bright-agrotech-nutrient-deficiency-chart.1052024/
I know Cervantes says in his grow bible that yellowing from an iron deficiency starts from the petiole (stem) and moves toward the tips. I don't see that in the pic but that might not rule it out. Any idea of the PH of the liquid inputs or the soil?

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Soil is promix HP so it's ph balanced and I'm using PH 5.9 water to feed.

It's early, it may be still adapting. Is your water source 5.9 or are you adjusting it. I would prefer a higher ph tap water myself.

My tap water comes out at 8.1
It's filtered well water that also gets softened with potassium chloride
I adjust down to 5.9

BurntByFire said:

My tap water comes out at 8.1
It's filtered well water that also gets softened with potassium chloride
I adjust down to 5.9

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Any ides of the PPM of the water? Aren't you supposed to avoid softened water to grow cannabis? I don't think potassium chloride is harmful to the plants but how much is in the water?

MustGro said:

Any ides of the PPM of the water? Aren't you supposed to avoid softened water to grow cannabis? I don't think potassium chloride is harmful to the plants but how much is in the water?

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Ppm of the water is around 200ppm from the tap.
I could run it through an RO but I've been told never run hard water through an RO and always soften before running through an RO lol

So either way I'm screwed.

I checked my softened water at the tap
It's Ph 8.2 and PPM 225

I checked the outside hose where there's no softened water
It's Ph 7.7 and PPM 170

Maybe my well water is perfect straight from the well?!?!

Maybe this is my issue?

BurntByFire said:

I checked my softened water at the tap
It's Ph 8.2 and PPM 225

I checked the outside hose where there's no softened water
It's Ph 7.7 and PPM 170

Maybe my well water is perfect straight from the well?!?!

Maybe this is my issue?

Click to expand...

Certainly worth trying the unsoftened water for a bit to see if it helps. The PPM and PH are better outside anyway.

Whoever told you to soften water before running through RO is a real dumbass.

They should have told you not to use softened water on your plants. Potassium chloride is better than sodium chloride but still too much chloride.

OldMedUser said:

Whoever told you to soften water before running through RO is a real dumbass.

They should have told you not to use softened water on your plants. Potassium chloride is better than sodium chloride but still too much chloride.

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The water depot lol
They told me it will clog up my RO system in no time

I'm going to just switch to RO
So should I use run my direct well water or my softened water through the RO?

Does an RO remove salt (chloride)?

Use the well water. Better yet send off sample to have tested so you know what those 170 ppm are. QAL labs. In a week you won’t have to wonder if you need to RO. You likely don’t.

BurntByFire said:

The water depot lol
They told me it will clog up my RO system in no time

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As he sold you a water softener no doubt.

Our tap water comes out of a dugout on my property at pH 8+ with 350 - 500ppm depending on the season and I've bought all the gear to build my own custom RO filter. When I bought this place 20 years ago he had a softener hooked up using pot. chloride and the ppm from that was 300 higher than the water only filtered to 5µ. I'll be filtering down to 0.5µ before it gets to the RO membrane. That won't reduce the mineral content but will greatly reduce the left-over sediment after the 5µ and give me longer RO filter life. People on city water don't get much fine sediment and most RO units only filter to 5µ. My pressure isn't great and fluctuates when the pump kicks in and out so I'll never hit the 75gpd my filter is capable of but lower pressure only hurts the quantity and not the quality.

I do have some use for that softener I put on bypass shortly after moving in. The 150L brine tank will make a great reservoir for the corner of the grow room and I'll be piping it in using a float switch to keep it topped up. Got a little tap to put near the bottom.

RO filters are designed to make hard water pure and remove 99.9% of all mineral salts, lead etc and there is no reason to soften the water first. You're just replacing the mineral salts in your water with potassium chloride which is just another mineral salt for the RO filter to remove.

Listen to @Troutguide and get your water analyzed to see what's in it and it may be fine to use on your plants tho I prefer RO for mine.

BurntByFire said:

Does an RO remove salt (chloride)?

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All the minerals in your water are in the form of salts so the answer is yes.