Is it Cal Mag deficiency?

[NamTran]

May I ask if this is Cal Mag deficiency?

Hi, The first pic is at the top of the canopy. The second is in the middle. But I found several leaves are showing the symptom like the first.

I am growing hydro with PH is at 6.0 (I'm not using RO, water at hardness of 0.4) as plants are now at the first stage of bloom (4 Royal Cheese Autos from RQS, good stuff, triple their size in mere 13 days.)

Nutrients are Canna Aqua without Cal Mag added and no PK boost (growshop cheated me and never sent those) . I just switched to Bloom nutrient as I saw one plant got the symptom of either Nitrogen intoxication or Phosphorus deficiency (very dark leaves, some brown spots, purple stems, slower growth comparing to the rest)

I have a fan over the canopy with temp fluctuate around 77 to 80, RH is around 65 to 73% ( can't help it, I reckon that it is a bit too soon to trim off fan leaves)

Here are some more detailed photos of the situation

 

[fanleaf]

Calcium

 

[ChiDude]

Cal-Mag should help

 

[Emilya Green]

I am not convinced yet, and meant to get back to this. Where on the plant is this occurring... just at the top or all over? Tell us more about your garden, soil or hydro... ph that you adjust to, nutes that are used... Then, do you have fans in that room and how high is the RH?

 

[fanleaf]

I am not convinced yet, and meant to get back to this. Where on the plant is this occurring... just at the top or all over? Tell us more about your garden, soil or hydro... ph that you adjust to, nutes that are used... Then, do you have fans in that room and how high is the RH?

I have similar concerns. I just figured with the very short question I would give a very short answer LOL. Sure does look like calcium to me but it could also be too much calcium that is causing calcium lockout LOL. Without more details it's pretty hard to diagnose or even guess.

 

[fanleaf]

Cal-Mag should help

Cal Mag is not necessarily the answer in may make matters worse. Please read down in my signature the link where it says how to ask for grow support. Add all the details that we are missing in order to give you a good idea how to fix it.

 

[NamTran]

I am not convinced yet, and meant to get back to this. Where on the plant is this occurring... just at the top or all over? Tell us more about your garden, soil or hydro... ph that you adjust to, nutes that are used... Then, do you have fans in that room and how high is the RH?

Hi, The first pic is at the top of the canopy. The second is in the middle. But I found several leaves are showing the symptom like the first.

I am growing hydro with PH is at 6.0 (I'm not using RO, water at hardness of 0.4) as plants are now at the first stage of bloom (4 Royal Cheese Autos from RQS, good stuff, triple their size in mere 13 days.)

Nutrients are Canna Aqua without Cal Mag added and no PK boost (growshop cheated me and never sent those) . I just switched to Bloom nutrient as I saw one plant got the symptom of either Nitrogen intoxication or Phosphorus deficiency (very dark leaves, some brown spots, purple stems, slower growth comparing to the rest)

I have a fan over the canopy with temp fluctuate around 77 to 80, RH is around 65 to 73% ( can't help it, I reckon that it is a bit too soon to trim off fan leaves)

Here are some more detailed photos of the situation

 

[Emilya Green]

Several problems that I can see then, and then I am going to let the hydro folks take it from there. First, get calmag. You are having a magnesium deficiency. Then, your pH is causing nutrient lockouts. Not using RO water, your water is going to have a very strong upward drift. Your mix is almost immediately going to be outside of the hydro pH range of 5.5-6.1. This is what is causing your phosphorus deficiency. You have multiple problems going on here, but it is fixable. First thing, get that pH adjusted down into the Hydro range. Also, you are not quite in bloom yet, but are transitioning. Veg nutes were still the more appropriate feed last time, and probably for the next week. Emmie out... hydro folks take over.

 

[NamTran]

Several problems that I can see then, and then I am going to let the hydro folks take it from there. First, get calmag. You are having a magnesium deficiency. Then, your pH is causing nutrient lockouts. Not using RO water, your water is going to have a very strong upward drift. Your mix is almost immediately going to be outside of the hydro pH range of 5.5-6.1. This is what is causing your phosphorus deficiency. You have multiple problems going on here, but it is fixable. First thing, get that pH adjusted down into the Hydro range. Also, you are not quite in bloom yet, but are transitioning. Veg nutes were still the more appropriate feed last time, and probably for the next week. Emmie out... hydro folks take over.

OK aside from that cal mag everything is fixed. Tank is changed with veg nutrient with a ph of 5.7. I'll add in some cal mag on Saturday.
Thank you very much for your help.

 

[Emilya Green]

That should help a lot... anxious to see them in a few days

 

[Mj76]

The one thing I haven't found is your EC. Please tell us you have a meter.....

 

[NamTran]

The one thing I haven't found is your EC. Please tell us you have a meter.....

Oh yeah, I feed light with EC of 1.2

 

[Mj76]

Then I definitely think they're under fed. I was doing 1.2 in veg and they were yellowing on me. I couldn't figure it out so I started bumping it up. With synthetics most of the N comes from Cal and Mag nitrate and Ionic has 2% N, which is low.

 

[NamTran]

Then I definitely think they're under fed. I was doing 1.2 in veg and they were yellowing on me. I couldn't figure it out so I started bumping it up. With synthetics most of the N comes from Cal and Mag nitrate and Ionic has 2% N, which is low.

I'll increase ec in a few week as they would be in flower. In fact they kind of almost overgrew my 3x3 tent so I am very reluctant to feed them more during veg time. I foliar fed them cal mag and reduce the PH so I hope that those brown spots will disappear.

*Edit: Sorry 1.2 EC is what I added into water, it adds up to total 1.6.

 

[Mj76]

No no. You were right with 1.2. I just looked at the girl again. Flip now!! You're gonna have a monster!

 

[NamTran]

No no. You were right with 1.2. I just looked at the girl again. Flip now!! You're gonna have a monster!

They are autos so I guess it should take another week to complete the transition.

 

[Mj76]

Oh I see. Well, with the smooth transition that autos do, I can't think of any reason to hold off.

 

[NamTran]

That should help a lot... anxious to see them in a few days

I applied Cal Mag. To hasten the process I foliar fed them twice. So far so good, it has been 16 hours and no more brown spot turned up.
However my RH is elevating to almost 70%. I checked and it is still within the desired VPD threshold but I want to reduce RH even more. Is it advisable to defoliate lower fan leaves? They are not receivinf much light anyway.

 

[Emilya Green]

So, you spray water all around the room, and then think you need to remove leaves to reduce the RH? There are reasons to clean up under the canopy before you go into flower, but this isn't one of them. Keep on the calmag... the brown spots will not go away, but it should stop the progression.

 

[NamTran]

So, you spray water all around the room, and then think you need to remove leaves to reduce the RH? There are reasons to clean up under the canopy before you go into flower, but this isn't one of them. Keep on the calmag... the brown spots will not go away, but it should stop the progression.

Haha sorry it was poorly phrased. I meant to say that the RH is high even before the foliar spray and now it is bloom time I am afraid it might cause issue.