Calcium deficiency late in flower..

I’m six weeks into flower on my current run and my one strain has definitely got a calcium deficiency. I was planning on giving them nutes for a further week before starting a two week flush. The buds still look really good. Is it still advisable to add cal-mag to my nute mix this late in flower..? Will that week receiving cal-mag still have a benefit of will it affect things negatively? It’s my first time I’ve had a calcium deficiency so I’m hoping to get some advice on this before I refill my res tonight..

Tkboy said:

I’m six weeks into flower on my current run and my one strain has definitely got a calcium deficiency. I was planning on giving them nutes for a further week before starting a two week flush. The buds still look really good. Is it still advisable to add cal-mag to my nute mix this late in flower..? Will that week receiving cal-mag still have a benefit of will it affect things negatively? It’s my first time I’ve had a calcium deficiency so I’m hoping to get some advice on this before I refill my res tonight..

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Yes give and cut any Grow component you would have used to compensate for the nitrogen in your cal mag.

Have you recently lowered the lights? Do your plants drink properly? We had calcium def due to lowering the lights too much too fast and got rid of it by adjusting enviroment according to VPD. Basicly the Cal def disappeared when we raised the heat a bit to get the stomata open and get the plant drinking properly. But your case might be different.

Rocket Soul said:

Have you recently lowered the lights? Do your plants drink properly? We had calcium def due to lowering the lights too much too fast and got rid of it by adjusting enviroment according to VPD. Basicly the Cal def disappeared when we raised the heat a bit to get the stomata open and get the plant drinking properly. But your case might be different.

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No my lights have been the same height for the past three weeks.. I could try raising them slightly though. Thanks for the handy info..

hotrodharley said:

Yes give and cut any Grow component you would have used to compensate for the nitrogen in your cal mag.

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Ok I’ve just done that thanks.. I’ll see how things go over the next few days..

Should be fine to add Cal-Mag, just be careful as nitrogen toxicity during this period could really stunt your plant.

Logan Burke said:

Should be fine to add Cal-Mag, just be careful as nitrogen toxicity during this period could really stunt your plant.

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Too close for this ^^! Less is best now.

I've encountered mag def symptoms when lights where too intense, I could tell cuz purple was showing up on the stems and petoles on the tops closest to light. At week 6 I cut all calcium supplements out, the girls crave sulfur and mag at this point. N2 is ur enemy now, I use Epsom salt. Give the plants what they crave. Some may disagree with me, but calmag is 40% total ppm til week 6 in flower, then I swap to a mag sulfur supplement at the same percentage. Mag is the 4th macro nute. Advanced nutrients puts mag in all there supplements, never have I seen a mag toxicity.

hotrodharley said:

Too close for this ^^! Less is best now.

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Yeah I might even dilute my solution a bit tonight to make sure I’m on the safe side.. thanks man