Nitro Deficiency or Nute Burn?

[Luketheduke]

At first I thought nute burn although im using fox farms grow big at half strength. But today i noticed its only the older lower/outer leaves affected. I think this might be nitrogen deficiency. Anybody?

Medium/grow method: Happy Frog mixed w extra perlite. Some in 3.5 gal plastic and one in Fabric smart pot.

Feed: and supplements used: At this point they can go about 48 hours before they need more water. For supplements they are on Fox Farm trio. Big Bloom, Grow Big then Tiger Bloom. They just got their first feed of Grow big-2 Tsp and CalMag-1 Tsp mixed into a gallon of water and PH down to 6. Each plant gets 1 Liter rn

water source: Well Water being PH adjusted to 6

Strain/age: G18. Starting week 4.

light used: Mars Hydro TS1000w at 100% at around 17 " above tallest canopy. (Was 22 but theyve closed the distance)


Climate: Grow tent in garage. Temp daily between 71°-83° F. RH is between 40-60%

 

[Mañ'O'Green]

Looks like a phosphorus lock-out Probably too much Calcium.

 

[low_and_slow]

phosphorus lock-out too much Calcium.


View attachment 1279493

Agree

 

[Luketheduke]

Looks like a phosphorus lock-out Probably too much Calcium.


View attachment 1279493

Thank you for the chart. What do you suggest I do from here? Water only?

 

[Mañ'O'Green]

Thank you for the chart. What do you suggest I do from here? Water only?

Yes.

 

[low_and_slow]

With HF and especially OF, I have had good luck only adding water until I could see the plant show signs of very mild N deficiency, or once she finished stretch. In flower I'd always give a little something, but for an autoflower you can get pretty far just on that medium without fertilizer.

 

[Luketheduke]

With HF and especially OF, I have had good luck only adding water until I could see the plant show signs of very mild N deficiency, or once she finished stretch. In flower I'd always give a little something, but for an autoflower you can get pretty far just on that medium without fertilizer.

How many weeks generally until they showed signs of N deficiency? I just want to be able to have a general guideline. Because im growing 2 other plants of the same strain that are being fed the same and arent affected yet.

 

[low_and_slow]

Depends on so much like pot size, how much perlite you watered it down with, light intensity, strain, etc.

With plain HF out of the bag, you can coast until the stretch is underway usually. Once she starts aggressive vertical growth is when you'll likely see a nitrogen deficiency pop up. You can mix worm castings into the top soil and water heavily to green it back up for a few days, but ultimately that's when you want to add a balanced fertilizer designed for flower production.

 

[Luketheduke]

Depends on so much like pot size, how much perlite you watered it down with, light intensity, strain, etc.

With plain HF out of the bag, you can coast until the stretch is underway usually. Once she starts aggressive vertical growth is when you'll likely see a nitrogen deficiency pop up. You can mix worm castings into the top soil and water heavily to green it back up for a few days, but ultimately that's when you want to add a balanced fertilizer designed for flower production.

See this is what i need help w i guess

 

[low_and_slow]

See this is what i need help w i guess

With those soils if you go REALLY big on the pot size (7-10g), you can almost finish a fast flowering auto in just water.

That said, grow big and tiger bloom both work as advertised when used in 1/8-1/2 dosage. To my recollection, full strength was always too much.