Week 7 - yellowing leaves / discoloration in new growth

[revilo95]

Problem: Both older and mid leaves are yellowing with some brown spots. Some leaves are curling upwards at the tips. On others, I'm seeing brown & yellow discolorations on some of the newer growth as well.

Medium/grow method: Fox Farms happy frog, 3 gallon smart pots

Feed: and supplements used: Fox farms trio following their feed schedule at 1/2 strength. Also using sensi cal mag at 1/2 strength.

water source: Tap water either left out overnight or with Campden tablets to clear chlorine. Always ph balanced to 6.5

Strain/age: Blue Dream and Northern Lights week 7

light used: Grown outdoors

Climate: Midwest, lately high temps and very high humidity with some rain

Additional info: I've only been feeding every other watering (about once a week) and using just ph balanced water every other time.

 

[revilo95]

Anyone have any idea?

 

[Mañ'O'Green]

Do you know the PH in the root zone? I would drop your input to 6.2 until you know what is actually going on in the pot. You need to get an Accurate 8 PH soil probe (or the clone) or a Blue Lab soil probe. If you go with Blue Lab be sure to get the correct one as they make several. Do not bother with any of the cheap ones as they do not work.

It looks like a combination of deficiencies up the feed to 75% Too much cal mag can lock out magnesium and potassium. Outdoors you do not need as much as under LEDs.

Campden Tablets are for wine making not gardening. Yes they will clear chloramines and chlorine from water. They also sterilize it and maybe your soil as well. If you actually have Chloramines use ascorbic acid - Vitamin C to neutralize it. The store brand is usually the cheapest without other stuff added in. 50mg per gallon will treat water with 3.8 PPM of chloramines. Verify you even have it first. If you only have chlorine (most do) then just aerating overnight is more than sufficient.

 

[revilo95]

Thanks for the help!!

For now, I think an accurate soil probe would be out of my budget. I spent about as much as I could on the set up thus far. Is there another way I can measure the ph of the soil? Perhaps runoff?

I'll be sure to stop using the campden tablets - I only have chlorine in my tapwater. I only used them a handful of times when I didn't have a chance to leave the water out overnight. I did have them on hand for cider making