Is this calcium deficiency?

I think I might have given this plant too much magnesium and now it's locking out some calcium. Does this look like calcium deficiency to you guys? It's in soil with organics.

Maybe too much nitrogen.

Looks a bit “hot” but good

Too much Mg interferes with K uptake as well. Could be that as calcium is usually rust spots only with minimal yellowing.

Also K def starts with yellowing of the leaf edges that eventually burn. Taken from fan leaves first.

Nutty sKunK said:

Too much Mg interferes with K uptake as well. Could be that as calcium is usually rust spots only with minimal yellowing.

Also K def starts with yellowing of the leaf edges that eventually burn. Taken from fan leaves first.

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That's what I was thinking. I added the same mixture to some other flowering plants and there was clearly potassium deficiency showing up so I was thinking the magnesium was locking out both the potassium and calcium on this one. Thanks for the reply.

Cousin Bo said:

That's what I was thinking. I added the same mixture to some other flowering plants and there was clearly potassium deficiency showing up so I was thinking the magnesium was locking out both the potassium and calcium on this one. Thanks for the reply.

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Well that may just be it bud. This chart helps a lot to figure out deficiencies

Nutty sKunK said:

Well that may just be it bud. This chart helps a lot to figure out deficiencies

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Oh ya. That's a great chart. I still don't understand it fully but use it all the time. What's confusing is the Stimulation/Synergism part. At least in my stoner mind. The black and green chart makes it seem like you need more phosphorus if you have extra magnesium and the red and green one seems like it says you need less phosphorus since it's more available.

I think the green and black one that you posted probably makes more sense to me because I think it actually needs more phosphorus when it has extra magnesium due to being able to use it faster. I noticed that the other plants that I have growing have been showing signs of phosphorus deficiency but I have a feeling it's just because it's using it up fast since it's in flower. I don't know. Maybe it'll make more sense if I smoke another bowl. Anyways thanks for the input.

Nutty sKunK said:

Too much Mg interferes with K uptake as well. Could be that as calcium is usually rust spots only with minimal yellowing.

Also K def starts with yellowing of the leaf edges that eventually burn. Taken from fan leaves first.

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Well it seemed like the progression of the yellowing slowed down for a bit but then I gave it 1/2 tsp potassium sulfate mixed into its water a handful of times. It seems to have made them a little worse. That makes me think that it is a Ca deficiency issue since K also locks out Ca but it doesn't look like the typical pictures I see of Ca deficiency. Not sure but it'd be nice to know for sure so I can prevent it next time. What do you think?

Cousin Bo said:

Well it seemed like the progression of the yellowing slowed down for a bit but then I gave it 1/2 tsp potassium sulfate mixed into its water a handful of times. It seems to have made them a little worse. That makes me think that it is a Ca deficiency issue since K also locks out Ca but it doesn't look like the typical pictures I see of Ca deficiency. Not sure but it'd be nice to know for sure so I can prevent it next time. What do you think?

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Not your typical calcium spots. A lack of K will
Cause the lower leaf edges to yellow then burn.

This looks like potentially the opposite. Too much K will burn the leaves highest up in the canopy. It’s marginal and you have some nice sized buds already!

Nutty sKunK said:

Not your typical calcium spots. A lack of K will
Cause the lower leaf edges to yellow then burn.

This looks like potentially the opposite. Too much K will burn the leaves highest up in the canopy. It’s marginal and you have some nice sized buds already!

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Well I think I might've figured it out. Since it didn't really look like either K or Ca deficiency and it wasn't making sense I decided to check the soil pH. Guess what? It was 5.7. I also read that K can lower the pH around the root zone so it would make sense that adding the potassium sulfate only made it worse. I went ahead and chopped last night at exactly 10 weeks. They're plenty done anyways. I left some of the branches and immature buds to see if I can turn it around and make her healthy again. Thanks for all your help.

I ended up with 72 grams so almost 2 1/2 oz. Not bad for only 50 watts in a tiny ass tent.

I thought I'd try flushing with a bunch of pH up to quickly raise the soil pH after I chopped it. I went a bit overboard because it wasn't happy after. The pH up was K based. Anyways after I noticed that it wasn't happy I started adding some gypsum and Epsom salt. It seems a little happier now and is giving off new shoots. Getting ready for round 2.