Cal issues

[Mwood1087]

I

'm using foxfarm coco loco and I contacted them about constant calcium issues. They told me they recommend ph of 6.2 to 6.4 for optimal growth. I flushed the plant and continued with a cal mag foliar spray and she bounced back just fine. I mixed up my nutes on a regular regimen and ph'd to 6.3. A few days after feeding this is what i get. I've had nothing but calcium issues on my last 2 grows. What can I do differently? What am I doing wrong?

 

[HugePeckerhead]

I

'm using foxfarm coco loco and I contacted them about constant calcium issues. They told me they recommend ph of 6.2 to 6.4 for optimal growth. I flushed the plant and continued with a cal mag foliar spray and she bounced back just fine. I mixed up my nutes on a regular regimen and ph'd to 6.3. A few days after feeding this is what i get. I've had nothing but calcium issues on my last 2 grows. What can I do differently? What am I doing wrong?

I personally think it's from the strains themselves. My recent harvest of white widow were super cal mag hogs. I had to use it every feed and water or else I started to see deficiencies. My current grow now I rarely even use it. I've also read that using LED lighting can also make you need to use it.

 

[MickFoster]

What is your feeding schedule?
Do you feed plain water?
Do you feed to substantial run off?
I have always found a 6.0 pH works best in coco.
Why don't you add the calmag to your nute mix instead of foliar feeding?

 

[Mwood1087]

I have read that certain strains require more cal mag. This being a bubba hybrid it needs a good amount from what I've researched. I generally feed every 2 to 3 days and RARELY if ever do I water with plain ph water. I currently use store bought ro water and ph accordingly. As far as run off.. I feed until I see some run off. Not a lot but some. I do add 5ml/gal cal mag into my feed but apparently it's not enough. I'm not sure if my ph was off as I was feeding at 5.7 prior. I also know that cal is best absorbed between 6 and 6.5 but everyone says 5.7 is optimal for coco. I started to foliar feed thinking it would boost the intake but I dunno if its locked out or not. Someone previously said my ppm was high potentially but I dont have a meter and cant get one until the end of the week. I still have some time to fix this before i flip as I'm going on vacation in 2 weeks, BUT would like to flip once i get back. Just mind blown right now haha

 

[MickFoster]

Have you considered using tap water?
I feed daily to run off and twice a day in flower.
Coco is drain to waste hydroponics.
If you use plain water it will mess up your cation exchange capacity and cause potential calcium problems.
Personally I would run a couple gallons of 1/4 strength nutes through it and start a daily feeding schedule at 1/2 strength.
Good luck.

 

[Mwood1087]

Right on mick. I had a 1/2 gallon mixed up that I split and topped with water. So now 2 gallons of heavily diluted nutes. I'll try it and see what happens!

 

[bobrown14]

What can I do differently? What am I doing wrong?

Try organic soil?? I dont have those issues. I used to but it was related to my water. After changing to filtered water lock outs stopped being an issue.

Could be a lot of things that are causing that.

Ca deficit looks exactly like Mg toxicity. Lots of folks use Cal/Mg to remedy and it makes matters worse.

So you have your water and your soil pH and the soil.

Either one of these 3 can cause your issue.

Start by changing 1 at a time wait a week and see. Then keep that change the same and change something else.

Not much you can do the change soil pH so look to the water for something in there.

Could be just a simple pH adjustment or some minerals/chems in the water causing the issues.

Basically the plant is not getting nutrients in a proper proportion.

Usually pH related but if its in the soil you can't change that very quickly.

I looked at the soil mix coco loco - they use Dolomite lime. That has too much Mg in it. Meaning the ratio of Ca:Mg is not optimal. Plants use up the Ca a lot faster than the Mg so then you get a Mg TOXICITY that looks exactly like your issue.

You need more Ca sources. Can scratch in a few tbs of food grade Gypsum but its marginal on Ca availability short term. But you will see a positive change over time say a few weeks.

3 things in this order

water pH - test and adjust
Water chemicals - filter (will fix the pH too)
Soil pH - top dress with Gypsum

 

[Emilya Green]

First of all, this is not a Ca deficiency... it is a magnesium deficiency. Ca deficiency shows up usually in the new growth and presents as spots in the middle of the leaf... not this.
I really doubt there is too much dolomite in the soil to cause a magnesium toxicity, because at those extreme values a lot more would be blocked out because of all the magnesium in the soil. If this were the case you would be seeing severe deficiencies of several macro nutrients and FF would no longer be selling this soil to pot farmers.
What the dolomite does is just what it does in FF Ocean Forest soil, it provides for a very fast positive drift of the pH as soon as you water. No matter where you come in at below 6.8, the dolomite quickly rockets the pH up to the upper end of the soil pH range. Guess what? Magnesium isn't mobile up there... it is most mobile down at the low end. When FF told you to adjust to 6.2, they meant it. There was a very good reason to come in that low. You didn't follow their advice, hence the continued presentation. Try 6.2. This should keep the problem from progressing. The spots you have developed will not go away, but if you stop the progression, the rest of the leaf will stay viable and there should not be any more progression. You tried calmag, and it worked... keep doing it.

 

[bobrown14]

I didn't say Ca deficit I said the ratio of Ca:Mg is not optimal. Meaning there's too much Mg likely from the fact that the soil mix has Dolomite lime added and very little other sources of Ca.

pH in soil doesn't change that quickly. The plants can change the soil pH local to the roots with root exudate as can the soil microbes change the soil pH local to the roots for the same reasons.

VERY difficult to have an Mg deficit.

Here's why:

Molecular formula of Chlorophyll (the stuff that makes leaves green) is :

C55H72O5N4Mg <----- See the SINGLE Mg molecule there on the end?

What would chlorophyll look like without that Mg molecule?

Plants use MUCH more Ca than Mg. When the ratio of Ca:Mg gets close to 1:1 (+6:1 optimal) plants begin to show an Mg toxicity. It looks just like a Ca deficit.


Different approach to the same end - check the pH of the water.

I like 6.5pH but thats me in soil only.

Here's a quote on Dolomite lime


"Your soil needs a calcium to magnesium ratio of somewhere between 7:1 (sandier soils) and 10:1 (clayier soils).


Some soil consultants might use different numbers but everyone knows you need way more calcium than magnesium.


Outside of these ranges, your soil will often have compaction problems, your plants will often have health issues and insect and disease problems, and you will have weed problems.


One of your most important goals in the garden is to add mineral fertilizers to move the calcium to magnesium ratio towards the correct range, based on a soil test.


The problem with dolomite lime? It has a calcium to magnesium ratio of 2:1. That’s way too much magnesium for most soils. Magnesium is certainly an essential mineral. Too much of it, however, causes many problems."

This is a general consensus from most soil science being done these daze. I'm not bashing anyone for using it, just as long as there are other sources of Ca to get the ratio right.

Gypsum is a shortish way to correct the problem. If the plant does not need the Ca it simply will not up-take it and Gypsum does not affect the soil pH.

 

[Mwood1087]

First of all, this is not a Ca deficiency... it is a magnesium deficiency. Ca deficiency shows up usually in the new growth and presents as spots in the middle of the leaf... not this.
I really doubt there is too much dolomite in the soil to cause a magnesium toxicity, because at those extreme values a lot more would be blocked out because of all the magnesium in the soil. If this were the case you would be seeing severe deficiencies of several macro nutrients and FF would no longer be selling this soil to pot farmers.
What the dolomite does is just what it does in FF Ocean Forest soil, it provides for a very fast positive drift of the pH as soon as you water. No matter where you come in at below 6.8, the dolomite quickly rockets the pH up to the upper end of the soil pH range. Guess what? Magnesium isn't mobile up there... it is most mobile down at the low end. When FF told you to adjust to 6.2, they meant it. There was a very good reason to come in that low. You didn't follow their advice, hence the continued presentation. Try 6.2. This should keep the problem from progressing. The spots you have developed will not go away, but if you stop the progression, the rest of the leaf will stay viable and there should not be any more progression. You tried calmag, and it worked... keep doing it.

I thought mg deficiency showed up as yellowing of the vanes and then developed spots if not treated? Should I get rid of my cal mag foliar spray and name an Epsom salt foliar spray? I've heard that will clear things up in a week or so? Or how would you remedy this Emilya?

 

[Emilya Green]

I thought mg deficiency showed up as yellowing of the vanes and then developed spots if not treated? Should I get rid of my cal mag foliar spray and name an Epsom salt foliar spray? I've heard that will clear things up in a week or so? Or how would you remedy this Emilya?

You are well past the yellowing of the veins and the red stems. You should stop relying on foliar applications to solve this problem and you should properly apply calmag as part of your nutrient program. You should also follow the advice that you were given about the 6.2 pH. Don't expect an instant fix... nothing happens that fast in the plant world. Foliar sprays to fix a magnesium problem are simply a band-aid... your plant needs real nutrition, now. Calmag at its maximum dosage is called for. That is all you can do really... the damaged leaves will not come back, and those that are more than 50% gone can be removed. The ones with less damage can repair all but the dead spots and still be viable leaves.

 

[Mwood1087]

I've been using 5mg of calmag since I started giving nutes. According to the bottle botanicare reccomends 5mg/gal. Should I increase the amount I give? Sprinkle epsom salt on the soil prior to watering?

 

[Emilya Green]

I've been using 5mg of calmag since I started giving nutes. According to the bottle botanicare reccomends 5mg/gal. Should I increase the amount I give? Sprinkle epsom salt on the soil prior to watering?

continue to do the same thing you have been doing. Just change one thing... a fundamental thing. Do not sprinkle epsom salt or you run a big risk of knocking your soil balance out of whack. Calm down and trust the advice you have been given from multiple sources... your problem is the pH... adjust to 6.2 every time you water.

 

[Mwood1087]

Thanks!