• Home
  • Forums
  • Medical Cannabis Cultivation
  • Cannabis Infirmary
  • Calcium Deficiency or nutrient lockout?

Calcium Deficiency or nutrient lockout?

  • Thread starter Thread starter VAgrower58
  • Start date Start date Aug 7, 2021
  • Tagged users Tagged users None

Calcium Deficiency or nutrient lockout?

VAgrower58 Aug 7, 2021 3 Replies 5,266 Views
Page 1 of 1 · Replies 1–4 of 4
1

VAgrower58

Posts
14
Reactions
14
Joined
Jul 27, 2021
Points
3
Aug 7, 2021
#1
Hey folks, having issue with brown spots popping up on lower leaves and slowly spreading upward. Can anyone tell me what it might be and how to treat it?

Grow info
Seeds: unknown hybrid strain, currently 9 weeks into veg, soon to flower
Water: straight from the hose, no ph treatment (measurements: 6.71 ph, 146 ppm), usually 1 gallon per plant every other day
Soil: Fox farm Ocean forest mix in 7 gallon pots, nothing added
Feeding: no nutrient feeding except for one application of worm castings
Environment: Outdoor grow so temps vary from low 70s to sometimes lower 90s, humidity range from 50-80%
Pest control: 3 applications of neem oil for what i thought might have been aphids, used jewelers loupe and could not find evidence of insects or eggs on leaves

I did a slurry test on my soils in all of my pots. Each test on my healthier plants came back to about 5.7-5.8 pH and ppms were 600-700. My plant that has the worst damage has a soil pH of 6.17. (I work in a lab so all measurements taken with lab grade equipment). Would these symptoms be indicative of a nutrient lockout of some sort? I have done research and cannot decipher between a pH induced nute lockout, or just a calcium or phospho deficiency. Any help is appreciated as I am approaching flowering and want to make sure I save my harvest!
 
Reactions: Schwer
Quote Reply

mancorn

Posts
1,901
Reactions
4,217
Joined
Aug 2, 2011
Points
263
Aug 7, 2021
#2
If you’re 9 weeks in without ever fertilizer, I would think that is the issue. Most soils and tap water have calcium and magnesium as they’re the two most common minerals in city water. You don’t need to worry about your water pH in soil (Aquaman has a good thread on pH in soil - do a site search), but 5.7-5.8 in FF soil seems real low. Both Ca & Mg uptake at 6.5+. (I would ignore your ppm readings as they would be from the FF soil amendments and EC from organic molecules are way off.)

 
Quote Reply

VAgrower58

Posts
14
Reactions
14
Joined
Jul 27, 2021
Points
3
Aug 7, 2021
#3
mancorn said:
If you’re 9 weeks in without ever fertilizer, I would think that is the issue. Most soils and tap water have calcium and magnesium as they’re the two most common minerals in city water. You don’t need to worry about your water pH in soil (Aquaman has a good thread on pH in soil - do a site search), but 5.7-5.8 in FF soil seems real low. Both Ca & Mg uptake at 6.5+. (I would ignore your ppm readings as they would be from the FF soil amendments and EC from organic molecules are way off.)

View attachment 1154673
Click to expand...
So do you suggest something like dolomite lime to help raise my pH? Then consider some nutrients? I did notice the FF was high in Nitrogen but relatively low in potash
 
Quote Reply

Cbfender

Posts
21
Reactions
12
Joined
Nov 19, 2021
Points
3
Nov 20, 2021
#4
In Va also. How did these turn out
 
Quote Reply
Page 1 of 1 · Replies 1–4 of 4
1

Thread info

Replies 3
Views 5,266
Started Aug 7, 2021
Latest post Nov 20, 2021
Starter VAgrower58
Forum Cannabis Infirmary

Latest posts

  • Blazing heat, smoke-filled skies, illegal! What could possibly go wrong?
    • Latest: Oldchucky
    • A moment ago
    General Outdoor Growing
  • Cpurola's Outdoor grow in Southeast Michigan 2026
    • Latest: EternalSun
    • 20 minutes ago
    General Outdoor Growing
  • 2026 Outdoor Grows! let's see em!
    • Latest: Hossgrows
    • 21 minutes ago
    General Outdoor Growing
  • Is it ready to harvest
    • Latest: GNick55
    • 41 minutes ago
    Photography Help
  • What’s GNick55 up too
    • Latest: Sdub23
    • 51 minutes ago
    General Indoor Growing
  • Home
  • Forums
  • Medical Cannabis Cultivation
  • Cannabis Infirmary
  • Calcium Deficiency or nutrient lockout?
  • Contact us
  • Terms and rules
  • Privacy policy
  • Help
  • Home
Community platform by XenForo® © 2010-2026 XenForo Ltd.
Menu
Log in

Sign up

  • Home
  • News
  • Classifieds
  • Forums
    • What's new Featured content New posts New Articles New articles New products Latest activity
  • Social
  • Strains
  • Live
  • Learn
  • Brands
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?