This meter should work right??
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In cannabis cultivation, the balance of calcium (Ca), phosphorus (P), and potassium (K) is crucial for healthy plant growth.
Excess phosphorus or potassium can lead to calcium deficiency in cannabis plants due to nutrient antagonism.
Phosphorus (P) Excess can cause Calcium Lockout.
High phosphorus levels can bind with calcium, forming insoluble compounds that the plant can’t absorb.
This often happens when growers overuse bloom boosters or phosphorus-heavy fertilizers during the flowering stage.
Symptoms: Stunted growth, leaf curling, weak stems, and brown or necrotic spots on leaves.
Potassium (K) Excess can also cause Calcium Deficiency
Too much potassium can compete with calcium for uptake in the root zone due to cationic competition (K⁺, Ca²⁺, and Mg²⁺ all compete for absorption).
This is common when using too much potassium-heavy bloom fertilizers or improper nutrient ratios.
Symptoms: Similar to phosphorus-induced deficiency—weak stems, slow growth, and leaf discoloration.
Solution for Cannabis Growers
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Balanced Nutrient Feeding – Ensure proper N-P-K ratios and avoid overloading with bloom boosters.
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Cal-Mag Supplementation – If using high P or K nutrients, supplement with calcium and magnesium to maintain balance. (If boosting P,K, also boost Ca)
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pH Monitoring – Keep soil or hydroponic pH within optimal ranges (5.8–6.5 for hydro, 6.2–7.0 for soil) to prevent nutrient lockout.
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Think I should flush my plants with distilled water??
Then start back with nutrients..
Have a 5-1 meter coming Wednesday..
But need to water tonight..
Bought distilled water..
Think I’m going to flush ..
Is that a good idea??
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They don’t really look any worse since I add cal and mag the other day..
Still about the same..
Don’t know what to do.
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Personally I would ride it out. Keep ph tight and skip a few feeds. I am in living soil and a flush is a no no mostly. Repairs take time. Watch the flower tops for green.
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Sound good..
If they start to get worse then maybe I’ll try it..
I’ll just give them the distilled water tonight like a regular watering.
Hopefully they stay the corse and don’t get worse
Thank you growbro…
Happy Growing
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Distilled is not my go to. Good tap that sits overnight to gas off chlorine and such typically has micronutes. I prefer it myself. Phed well. But many use ro and distilled.
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I don’t have good tap water..
Heavily chlorinated..
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That is why let sit. SMALL amount of vitamin C will negate that chlorine. It gasses off so easy to remove.
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Spot on info Pappy, well put Brother 
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Great read. Glad you posted this @ScottsBuds . And thanks to the contributors.
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Just to add to what @Storm said I use the aquarium tap water conditioner because I usually forget to fill the bucket early enough to off gas it lol.
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Your welcome growbro…
Just trying to get the ladies back on track…
Happy Growing…
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Little update should get new meter tomorrow before feed tomorrow night.
Gave just water on last feeding.
Nothing has gotten worse maybe a tad..
So not thinking it’s nutrient lock rather a calcium deficiency…
So going to feed tomorrow
After I get the new meter
Hopefully will be back on the right track soon…
Again thanks to everyone for your help and advice…
Happy Growing…
What kind of medium are you growing in? Promix soil. coco. fox farms?
What nutrient line are you using?
Just for the record I feed with straight chlorinated tap water. Without removing the chlorine. My plants are fine. Watered/fed every 3 days from tap to tote to plants in under 15 minutes.
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Soil if ff bushdoctor cocoloco
With mix in bottom 1/3 of this super soil concentrate
FF nutrients
Cal and mag and big bloom
They loved the soil …
I just got something out of whack…
But thinks are looking better..
Happy Growing
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Did load on my response
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Guess from here we’ll see what those meters say.
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My problem is get a reading for run off…
The auto pots have a gauge with a hole maybe I can pull it out and check thou that hole ..
If not guess could drill a bigger hole in somewhere else..
Happy growing..
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