Magnesium Problem Worsening

[BobCajun]

Unfortunately it could be a few different things that look like that. I don't know for sure it was just light, just a possibility. Here's a pic that may be helpful. You did mention putting 2 spoons of lime per gallon of soil, which could cause some kind of lockup of certain other nutes, like iron. Dolomite lime is less alkali so usually preferable to regular lime.

From this pic, could be zinc got locked out, or manganese, iron etc. I haven't investigated the subject enough to be able to tell just from your photo. Your pH seems a little on the high side, and whatever you used to test it could be inaccurate. Maybe put some slightly acidified water through it, like a little citric acid. Citric acid solution is usually around 4.5, which is low but not low enough to harm roots. That would require lower pH than 4. It's also a very good fungicide. You also added a lot of mg and ca supplements, maybe too much. With dolomite lime you get both cal and mag, not much chance of deficiency of either if you use that. Maybe you did, you just said lime. Though doing a quick search about lime I found this, so maybe you made the right choice after all, though possibly no lime would have been best of all.

When Should You Use Dolomitic Lime?
You should only use garden lime when you have a soil test showing a huge deficiency of magnesium in your soil.

Even then, calcium carbonate (calcitic lime) is generally the way to go because it has a small amount of magnesium and often a calcium to magnesium ratio of about 6:1, with a calcium content of 30% to 40% or more.

Instead of dolomitic lime, I use calcium carbonate regularly in my garden, but even then, only when I need it. A soil test is a main way to find out if you need it and I talk about soil nutrient testing often on my website.

Adding fertilizers based on the results of soil pH kits just doesn’t make any sense (that’s a good article that will show you why).

source

Here's another one. I just google imaged "Cannabis deficiency signs".

 

[thick sticky sock]

you frequently add cal mag to amended soil with lime, Cal, you are cal magging it to death, are you adding any Epsom salts with it? With soil repeated applications and flushing will fuck it right up the shit pipe, feed it some tea, let it chill for a while, otherwise why even bother going "organic" if you just end with a different pile of bottles and the same headache of deficiency/over feed circle jerking

 

[BobCajun]

you frequently add cal mag to amended soil with lime, Cal, you are cal magging it to death, are you adding any Epsom salts with it? With soil repeated applications and flushing will fuck it right up the shit pipe, feed it some tea, let it chill for a while, otherwise why even bother going "organic" if you just end with a different pile of bottles and the same headache of deficiency/over feed circle jerking

I do think too many people think they need cal/mag. I've never used anything but straight hydro nutes, usually GH. The FloraNova Grow works great, around 800-1000 ppm in drain to waste pots of perlite. I never use the Bloom type because it has too much phosphorus for my liking but the Grow is just right. Their MaxiGro powder also works okay but not as good as the liquid with the brown stuff. The brown stinky stuff seems to be beneficial, whatever it is. Messy as hell but plants love it.

 

[somedude584]

Unfortunately it could be a few different things that look like that. I don't know for sure it was just light, just a possibility. Here's a pic that may be helpful. You did mention putting 2 spoons of lime per gallon of soil, which could cause some kind of lockup of certain other nutes, like iron. Dolomite lime is less alkali so usually preferable to regular lime.

From this pic, could be zinc got locked out, or manganese, iron etc. I haven't investigated the subject enough to be able to tell just from your photo. Your pH seems a little on the high side, and whatever you used to test it could be inaccurate. Maybe put some slightly acidified water through it, like a little citric acid. Citric acid solution is usually around 4.5, which is low but not low enough to harm roots. That would require lower pH than 4. It's also a very good fungicide. You also added a lot of mg and ca supplements, maybe too much. With dolomite lime you get both cal and mag, not much chance of deficiency of either if you use that. Maybe you did, you just said lime. Though doing a quick search about lime I found this, so maybe you made the right choice after all, though possibly no lime would have been best of all.

Here's another one. I just google imaged "Cannabis deficiency signs".

I should of specified, of course I'm using dolomite

I think you guys may be right, I may have been mistakenly diagnosing a K deficiency as a Mg deficiency, perhaps caused by repeated applications of the Cal-Mag. It's my understanding that it is the Cal that locks out potassium, not the magnesium? Do I have that correct? If not could I see a source that says otherwise? I haven't been able to find anything suggesting Mg to lockout K.

Thankfully, as some of you have pointed out, they are very fast growing (thanks supplemental CO2!) and therefore suck all that water up quick. Pots are already dry, so it's safe for another watering. I will try straight water this time and perhaps a tea on the next watering. Hopefully they'll perk back up. I really appreciate all the discussion that has taken place here, and will continue to update.

Feel free to continue debating and or sharing your opinions!

 

[somedude584]

Langbeinite mixed in your soil will solve your issue. It will cover your mag and potash def.

I have thought about using that in my soil but the super high K value kind of made me uneasy.

I usually just amend my soil with neem cake, azomite, humic acid, and dolomite.

How do you recommend using langbeinite? Is it slow release?

 

[OldMedUser]

So that we are looking at the same things. This is his 3rd picture.
This is not a deficiency pictured here? This is from light?

If anything that third pic looks like the beginning of toxic salts buildup, (TSB), to me. He's already added too much Mg and who knows what so adding more ain't gonna make it better.

The yellow in the top growth is from the rapid growing of the plant and just need a day or two to turn green. I see that in my plants all the time and then I know they are loving it. I tend to measure heights regularly and know when they are vegging fast or slowing down almost right away.

Because of my low humidity problem where I live I have a lot of experience with TSB and will be making sure I get a better humidifier to prevent the vapour pressure deficit that has plagued me for the last 16 years. I didn't clue in to how much better my plants grew without crispy leaves later in flower when I had higher RH but I got it figured out now.

But go ahead and toss more of the same at it. That'll fix it for sure.

 

[BobCajun]

Too much heat and humidity, night temps over 95 and humidity 80. Ffof, 5 weeks, only one half dose of gh flora nova grow at week 4.
View attachment 4004901 View attachment 4004902 View attachment 4004902

WTF dude, that's iron deficient right there. At least that's my amateur diagnosis. New growth yellow. Guess that'll happen when you only feed the fuckers once in four weeks.

 

[newgrow16]

WTF dude, that's iron deficient right there. At least that's my amateur diagnosis. New growth yellow. Guess that'll happen when you only feed the fuckers once in four weeks.

Humidity at night at 85% and temps with low of 90 and high of 99 had nothing to do with these?

 

[somedude584]

Humidity at night at 85% and temps with low of 90 and high of 99 had nothing to do with these?

Obviously that's not helping. Why don't you have your temp and humidity in check?

 

[Rasta Roy]

I have thought about using that in my soil but the super high K value kind of made me uneasy.

I usually just amend my soil with neem cake, azomite, humic acid, and dolomite.

How do you recommend using langbeinite? Is it slow release?

It's slow release but is available fairly quickly, I only use 1/4 cup per cubic feet and I only reamend with it every other grow.

 

[Buba Blend]

I posted this early before really seeing his problem and was careful not to say he had a Mg problem but said what I would do if I had One.

If it is a Mg deficiency and they were my plants, what I would do is give it a small dose of Epsom salt dissolved in water that you water with and I would foliar spray the fan leaves avoiding overspray if there are small buds around. The amount I would use would probably vary from what others use, I'd probably use about 100-150ppm's, not sure what that is in tsp per gallon.

What about my second post here. is my second post describing a TSB?

I agree with you. Took another look at the pics and I'm seeing the likely K deficiency. There is probably plenty of K in the soil. It probably is not being taken up by an imbalance of cal/mag ratios or from to much N. Likely to much Mg was added.

If anything that third pic looks like the beginning of toxic salts buildup, (TSB), to me. He's already added too much Mg and who knows what so adding more ain't gonna make it better.

The yellow in the top growth is from the rapid growing of the plant and just need a day or two to turn green. I see that in my plants all the time and then I know they are loving it. I tend to measure heights regularly and know when they are vegging fast or slowing down almost right away.

Because of my low humidity problem where I live I have a lot of experience with TSB and will be making sure I get a better humidifier to prevent the vapour pressure deficit that has plagued me for the last 16 years. I didn't clue in to how much better my plants grew without crispy leaves later in flower when I had higher RH but I got it figured out now.

But go ahead and toss more of the same at it. That'll fix it for sure.

Excellent about the improvement with increased humidity. I have the same problem with low humidity. I found a home depot evaporative cooler floor type unit helped me out. When needed it lowers temps about 1 or 2 degrees and increases humidity 10-15%.

 

[newgrow16]

outdoor shed, no ac, SoCal, lights on at night off during day. usually high temps in SoCal have low humidity, last week I could not get temps or humidity down when lights off. personal limitations on where to grow is all I can say.
I don't think it is a nutrient problem.

 

[Buba Blend]

outdoor shed, no ac, SoCal, lights on at night off during day. usually high temps in SoCal have low humidity, last week I could not get temps or humidity down when lights off. personal limitations on where to grow is all I can say.
I don't think it is a nutrient problem.

So we are on the same page. When you say: I don't think it is a nutrient problem.
Are you talking about your plants or the Original Posters plants?

 

[somedude584]

So we are on the same page. When you say: I don't think it is a nutrient problem.
Are you talking about your plants or the Original Posters plants?

Pretty sure he's talking about his own and referring to Bob's comment about the iron def.

Should probably make his own thread though TBH.

 

[newgrow16]

Sorry just trying to figure out how much I f upped, deleted pictures and will start a new thread.

 

[Buba Blend]

Sorry just trying to figure out how much I f upped, deleted pictures and will start a new thread.

No worries. Duel conversations can happen, sometime we read something and go off topic but it's always cool to be specific to who you are chatting with and respecting the OP.
When you do start a side conversation for a few posts in another persons thread always quote the person you are chatting with or it looks like it is to everyone.

 

[Xs121]

It's my understanding that it is the Cal that locks out potassium, not the magnesium? Do I have that correct?

Yes. Ca is antagonistic to K

 

[somedude584]

Yes. Ca is antagonistic to K

Cool beans. Just started a pre-flower tea with no Mg or Cal. Sea Kelp, Earth Juice Bloom, some Hydroguard (recently replaced Hygrozyme with this), smidgen of Earth Juice Grow, and some good ole' molasses. Kept it light this time with all of the above, but hopefully the imbalance will resolve itself and the addition of K will improve things. No more Cal-Mag!

 

[Buba Blend]

If anything that third pic looks like the beginning of toxic salts buildup, (TSB), to me. He's already added too much Mg and who knows what so adding more ain't gonna make it better.

The yellow in the top growth is from the rapid growing of the plant and just need a day or two to turn green. I see that in my plants all the time and then I know they are loving it. I tend to measure heights regularly and know when they are vegging fast or slowing down almost right away.

Because of my low humidity problem where I live I have a lot of experience with TSB and will be making sure I get a better humidifier to prevent the vapour pressure deficit that has plagued me for the last 16 years. I didn't clue in to how much better my plants grew without crispy leaves later in flower when I had higher RH but I got it figured out now.

But go ahead and toss more of the same at it. That'll fix it for sure.

I think I got confused and we were talking about two different growers plants.

 

[OldMedUser]

I think I got confused and we were talking about two different growers plants.

I cannot raise an argument to that logic so I think we should not give a flying fuck and both live to fight another day!