Possible mag deficiency

[kushedy]

Day 28 of flowering & I think I may have a slight mag deficiency but I’m not sure. They’ve been fed nothing but maxibloom & 1ml per litre of calmag (1.5ec). Temps are 24 c


A couple of days ago I added a teaspoon of Epsom salts on top of the calmag & maxibloom in a 10 litre mix as I thought the leaves maybe showing the taccoing effect & hence slightly mag deficient.

This didn’t seem to make them any better or worse.


In general they look pretty healthy bar a little tip burn (ec was reduced off the back of that) & the upturned edges.
This is my first proper grow with some new LED’s (cree cxb3590’s) so I’m still testing hanging distances & wattage output. I have read reports from other growers using CXB3590's that the light source has made their pants extra hungry for calcium or mag or both.



I’m not entirely sure if I need to add more mag or if this relates to my lights being to close, to far away or something else in the environment. Whatever it is isn’t giving them too much trouble which is good but I would like to try & perfect the growing environment to remove anything that could stress the ladies.

If anyone has any ideas I would be grateful of any suggestions.

 

[Speed of green]

What's the humidity like? Lower RH can cause the canoe. Plants look healthy otherwise. KISS is simple and effective.

 

[kushedy]

Thanks for the response @speed of green. Don't know right now. Forgot to take a reading before lights out. I will take a reading tomorrow morning & update the thread.
I new someone was going to ask me for that. The one thing I forgot to check before lights out doh!

 

[kushedy]

The humidity is reading 52%. Could be a tad lower but I wouldn't have thought a huge problem at this point.

 

[HqFarms]

Those girls are burnt. Back off the nutes some more

 

[kushedy]

cheers hqfarms I'll knock the ec down a few points & see if they level out

 

[Peripheral]

The humidity is reading 52%. Could be a tad lower but I wouldn't have thought a huge problem at this point.

52% is only going to cause growth problems and affect your yield negatively..

You are forcing the stomata to close and the plant will use nutrients and water in improper balances..

 

[kushedy]

I'm not going to lie, knowledge of humidity levels & manipulation is not my strong point. I will read up a bit. In the mean time what humidity range should I be aiming for?

 

[HqFarms]

I'm not going to lie, knowledge of humidity levels & manipulation is not my strong point. I will read up a bit. In the mean time what humidity range should I be aiming for?

You are fine at 52%. If your air circulation sucks then shoot for 40% during flower. Now if you have great circulation and been growing for a little bit you can shoot for perfect vpd. Vpd is more than just saying at 80 degrees you should be at 70%. With vpd you are more worried about leaf temps.

For you I would be more focused on keeping night and day temps within 10 degrees or closer and sticking with the standard 40% humidity

 

[Budley Doright]

I would be inclined to take some of the comments here so far with a grain of salt...

As far as magnesium def goes.... it normally shows up in late veg.....I dont see much...

Remember it... like nitrogen is translocatable in the plant... if you get a little of that happening in late flower its not a big deal....

While the tips of your plants aren't pristine they also aren't bad.....

There are worse things you might do than nothing at all....

 

[prune]

I'm not going to lie, knowledge of humidity levels & manipulation is not my strong point. I will read up a bit. In the mean time what humidity range should I be aiming for?

Lol, your RH is fine, the VPD Nazi's post that shit on every thread these days, you will notice they are usually the low post wonders with little practical experience.

Did you know that Molasses causes VPD, and it's aggravated by butane toxicity but flushing can fix it if you use drip-clean and No-till?

 

[Old Toker]

There are worse things you might do than nothing at all....

Well said.

 

[troutman]

If you still think it's a magnesium deficiency.

Then add the tiniest amount of epsom salt to your water once a week.

 

[kushedy]

Thanks for all the responses.
I did have a little read up on humidity control. I hadn't read anything on it for a very long time. From what I read my humidity should not be an issue at this point. Better at 40% but not a huge problem at 52%.
I didn't have time to get into the whole vpd thing.
My airflow is pretty good in general plus I managed to squeeze a box fan in there a while ago that the majority of people would consider over kill.
I didn't notice any improvement of reducing the ec. I have now got to the point of adding a pk booster so the feed rate has changed completely.
I had previously tried a little epsom salts but it did not appear to make any difference.
This is not something that cropped up when I was growing under hps.
Not the end of the world as the ladies all looked very healthy bar the upturned edges.