Cal/Mag issue, or not enough nutes period


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My plants are doing well overall, but can someone let me know if they think this is a cal/mag deficiency? Day 23 of flower, I feed now full nutes every second watering.

I'm on my water-only day, so I decided to give a 3/4 dose of cal/mag in the soil (usually I just foliar spray, but it's a bit worse).

Could this be caused by not enough nutes in general and not just calmag? Should I be doing full nutes every water?

fwiw, only a handful of leaves are discoloured, all below 3/4 from the top of the plant(s).




Active Member
I use cal/mg with my reverse osmosis water with even my plain water feeding. The way I look at it is I'm adding the CalMg to make the RO water more like tap water, so I feed it everytime I water. I personally use nutes in 2 waters in a row, then 1 plain water. I sometimes use a little less than the full nute does out of paranoia. That could possibly calcium deficiency, either from actual lack of, or due to PH lockout. In any case by day 23 of flower some of my girls always show some problem or another, but so far along I usually just ride it out and stick generally by the normal feeding schedule.


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I had that same problem ,knowing it wasn't cal mag,I flushed moved outer edge she was good to go.leaves never recover though,she's trying ti dissipate water and she's got too much nutes not enough water


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Nope that IS calmag for sure.. I had that problem a few years back and tried a bunch of different calmag supplements and still had it. Until I used general organics calmag and believe me I havent had a problem since.. Most other calmags are geared toward hydro and are very weak, but I use 3 teaspoons per gallon every watering and these bitch's love it.. You can also supplement with lime if using soil or soiless mix's


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"Calmag" is a product not an element or single nutrient. The two distinct elements cause different symptoms when deficient.
The reason the product contains ca and mg is because tap water usually contains both. If you are using ro water or soft tap water, you need a product that replaces those missing elements. This is why ca def is often accompanied by mg def.

i see ca def in your pics. You need calcium. I don't see mg but its unlikely that the mg in cal mag would hurt. Again, def in one usually means def in the other. Epsom salts won't help with ca def.

Part of the reason you need ca is to buffer acidic nutrient solutions. You add cal mag so you start out with a base to add thevrestbof the nutes to. The plant also uses more ca during flowering. Soil often comes with ca in the form of oyster shells or lime. This wears out over time and needs to be replaced.