Dialing In MEGA CROP for Auto's

[GeorgeCloney]

some questions for @pop22 @GeorgeCloney and @4d-Rock :

Like @4d-Rock I'm using ProMix HP with MC. I personally have a ton of MC v2 and like 4d-Rock, I run into issues every single f'ing grow early into flowering. My leaves turn yellow and start to show brown spots as time goes on to the point where the leaves look like they're decaying. In fact, the pictures of issues that 4d-Rock has shown with their grows could be photo-copies of my grows, the similarities are so exact.

Now for the questions;
with ProMix HP, what PH are we targeting. Read this whole bloody thread and I'm still not 100% clear what PH zone I should be aiming for. Some posts say 5.8 - 6.2, some say 6.0 - 6.4. which is it? I've been told specifically to use 6.2 with ProMix.

I HATE quitting, so I would REALLY like to be able to master MC with ProMix HP before I bail and switch to another medium. I don't see any reason why I wouldn't be able to master this but I'm beginning to think that they're not a great paring with each other.

All that being said, according to suggestions early on when I started using ProMix, I've been going with the PH 6.5 range with MC and ProMix HP, swinging between 6.2 and 6.5. My current grow, while very green and healthy during veg, has yet again gone to shit during flower. So I've started adjusting the PH to about 5.9ish as the run off water is now showing 6.0 to 6.4 PH.

It's only been about 4 or 5 days of lowering the PH, but for all I know, I'm doing it wrong, 'cause I believe I'm still seeing further yellowing of the leaves, just like 4d-rock has.


Next question is for IF and WHEN I decide to switch from ProMix HP to soil. ( I have maybe another grow or two left of ProMix in my bin)
For those of you using "soil" what are you specifically talking about? The word soil has been used to describe so many mediums now, I have no bloody clue what anyone means anymore. I think I even read a post in this thread from @GeorgeCloney use the term "soil" with (peat and coco) in brackets. If I'm not mistaken, isn't that a "soilless"?

Reason I'm asking about the soil is because after I mix my MC with my tap water (20-30ppm at about 7.6 PH), the solution stabilizes long term at 6.4-6.5, give or take a point either direction as PH swings occur with city water.

So if I could just use a true "soil" instead of a soilless, I won't have to dick around with PHing or deal with the runoff. My real confusion is, real soils are rich in nutrients and microbial life already, so by using a soil and then using MC right from seedling, as both @pop22 and @GeorgeCloney have mentioned they do, wouldn't that be too hot? wouldn't a rich soil + the use of MC so early just kill the plant?

Where I live, I have access to all sorts of stuff. so I guess I'm trying to figure out what this "soil" is everyone's talking about. Like what is it? Surely not potting mix? I live in BC Canada, so we have A TON of "soil" options here. Living soils, compost soils, flower bed soil, top soil, potting mix soil....

If I wanted to switch to soil while also using megacrop, what the hell am I looking for in a soil? For example, there's even this stuff I can readily purchase, https://www.reindeersnatural.ca/Brown_Gold.htm says it can feed plants for up to 4 to 6 months. I imagine if I used this stuff with MC, I'd burn the plants to death in a couple weeks.

So what is "soil"? lol. What kind of soil should I be looking for when using MC right from seedling all through to harvest?

In my mind, if you guys are using actual "soil" as well as MC right from seedling without burning your plants, your soil must be pretty inert? Or?

Thanks for taking the time to read my confusions, lol!

My first question would be.
Are you only having issues with the Promix MC combo?
Are you having these issues under LEDs or outside as well?
I want to paint a verbal picture in your mind ok...
Promix, is like that serrated plastic straw we got Easter eggs in 30,40 years ago.
Now imagine, getting it wet...then letting it dry...and it would be full of powdery stuff.
Well the stuff in question would mostly be calcium.
Ok, let me continue while my paint brush is wet!
Now imagine your pot (regardless of size).
Actually lets work with,say a 3 gallon pot.
When your plant is 6 to 12 inches tall in this 3 gallon pot, veging...no issues right....
Ok, the soil (Promix, gets wet, ..stays wet for a couple of days,...cause the roots are small and short in this 3 gallon pot..
Still with me?...
Ok,
Fast forward the explanation to a 2 foot plant starting to stretch going into flower.
Same plant, same pot.
The plant now needs to be watered more often because of evaporation and dehydration.
The soil (promix) is now getting over loaded with nutrients( saturation)...and dries out where the root tips end (worst in an airpot or smartpot.
We need to over feed the plant for growth on one hand, but struggle with the dehydrating soil on the other.
Lets compound this problem with, what is staying in the soil.
Pretty much everything, except calcium,...which the plant consumes as much as it wants/likes.
But at a certain point, the soil gets saturated and the plant now gets over fed with everything, or conversly underfed calcium ...
Explaining you calcium def'c.
MC, is a very good product,BUT.
I feed light through veg, 450 to 500 ppm.
(The first 50 ppm is calmag, then topped to 450 or 500, pending the plants feeding needs).
As pop said, going to 600 is fine IF your SOIL doesn't retain the over feeding.
Most people are having issues with MC because they over feed.
Causing soil saturation.
Which is why the typical first recommendation is FLUSH and start over.
My stupid analogy to this is to feed the fat kid, then starve him weeks before prom.
Or, go easy, through out...
Most usually get my point.

 

[BCBUDY]

My first question would be.
Are you only having issues with the Promix MC combo?
Are you having these issues under LEDs or outside as well?
I want to paint a verbal picture in your mind ok...
Promix, is like that serrated plastic straw we got Easter eggs in 30,40 years ago.
Now imagine, getting it wet...then letting it dry...and it would be full of powdery stuff.
Well the stuff in question would mostly be calcium.
Ok, let me continue while my paint brush is wet!
Now imagine your pot (regardless of size).
Actually lets work with,say a 3 gallon pot.
When your plant is 6 to 12 inches tall in this 3 gallon pot, veging...no issues right....
Ok, the soil (Promix, gets wet, ..stays wet for a couple of days,...cause the roots are small and short in this 3 gallon pot..
Still with me?...
Ok,
Fast forward the explanation to a 2 foot plant starting to stretch going into flower.
Same plant, same pot.
The plant now needs to be watered more often because of evaporation and dehydration.
The soil (promix) is now getting over loaded with nutrients( saturation)...and dries out where the root tips end (worst in an airpot or smartpot.
We need to over feed the plant for growth on one hand, but struggle with the dehydrating soil on the other.
Lets compound this problem with, what is staying in the soil.
Pretty much everything, except calcium,...which the plant consumes as much as it wants/likes.
But at a certain point, the soil gets saturated and the plant now gets over fed with everything, or conversly underfed calcium ...
Explaining you calcium def'c.
MC, is a very good product,BUT.
I feed light through veg, 450 to 500 ppm.
(The first 50 ppm is calmag, then topped to 450 or 500, pending the plants feeding needs).
As pop said, going to 600 is fine IF your SOIL doesn't retain the over feeding.
Most people are having issues with MC because they over feed.
Causing soil saturation.
Which is why the typical first recommendation is FLUSH and start over.
My stupid analogy to this is to feed the fat kid, then starve him weeks before prom.
Or, go easy, through out...
Most usually get my point.

haha, I like your analogy!

to answer your questions, for the first question I'm not sure what you're asking. my immediate answer would be, yes, I'm having trouble with the ProMix MC combo, which is why I'm asking. (sincerely not being sarcastic, just wondering if I took your question out of context)

for the second question, I'm using an LED. Electric Sky ES300 V3

I get what you're saying with your analogy, but I'm actually pretty good at keeping the pots damp in between feedings. so whenever I check my run off ppm, it's usually only about either 50-100ppm over or under what I put in and then the following feeding I'll adjust based on the previous results.

so if run off was 100 over last time, I'll feed 100 less next time, I'm pretty good at balancing the in with the out. which is why I don't believe I'm over or under feeding... BUT I'm not experienced enough to claim that in fact, I am or aren't under or over feeding.

that said, I've been PHing to 6.5 with promix until very recently, as in a few days ago. thinking I've been f'ing up the PH, causing lockout. hoping lowering the PH to 6.2'ish for the next week or so will at least prevent any further damage. because right now, my plants are as yellow as a shitty drawing of the sun by a 3 year old with a crayon.

 

[GeorgeCloney]

Do not lower you PH.
This will cause further calcium def'c.
There is nothing wrong with doing 6.2 to 6.6 in peat with MC.


The yellow leaves is typical (on the fan leaves I suspect), are happening because of N def'c.
So up your ppms another 100.

The analogies work.

N Is the meat in the stew.
To get more N, I'm obligating you to eat more potatoes in the process, see the issue?

A work around?...

@pop22 makes his feed in a conentrate..
(like a 1/4 cup MG per gallon in a windshield washer fluid bottle).
Then adds this liquid mix to water.
Wait till the next day to adjust your PH.

He can give you the details.

I have found that feeding a little fulvic acid or ReCharge prior to flower also help with both N and P absorption.

 

[4d-Rock]

You know what, I’ve been playing around with this just as you mentioned @BCBUDY and I really feel your pain. It seems when I make changes I can make slight improvements but often run into slightly different problems.

It is frustrating to see others have such success and not being able to make it work and I’ve also been thinking about either trying a different medium or moving on from MC.

Since I got a soil probe and monitoring my pH more with that and runoff, I find that when things start to go bad, what often happens is the Pro-mix is plummeting in pH. And I mean down to low 5s. It doesn’t always happen but it’s a common theme. I’m currently playing around with adding some extra dolomitic lime to see if that helps later on with the pH. I could also be totally wrong on this though.

I will also say that the liquid concentrate also helps. I have more problems pop up when im mixing small batches with the dry powder. I usually make 300ml with 30g, so 10mL = 1g when I’m mixing.

I’ve also been working on fine tuning my environment. I think that also plays a part as it sort of dictates the flow and if your off the mark it changes what is taken up and what is left in the medium. While I still run into issues, it has helped.

 

[Mañ'O'Green]

You need to be flexible a bit with your fertigation schedule in soil and peat of course hydro is every time. A good starting point for soil is weekly and for peat 2 times a week.

I am fairly certain I have run down the out of balance element in MC and it is not calcium it is sulfur. I am in the process of verifying this. I am willing to go out on a limb based on Bro-science. I have no sign of out of balance in my current grow as I have corrected for this. Here is the results of mathematical extrapolation from the Guaranteed Analysis.

3.5g MC v2. in one gallon of RO water. 500 - 600 PPM total is a good level for Autos. The Phosphorous is a bit too high but cannabis can tolerate up to about 100 without issues if everything else is good. Magnesium is barely in the green and sulfur is deficient.

If you add a gram of Cal-Mg the total PPM is too high and sulfur is still deficient.

If you add .5 gram of Magnesium Sulfate (Epsom Salt) You get a winning balance with the MC v2. You can use this in starting water up to about 200 PPM without calcium issues but it will be high.

 

[Kyote]

You know what, I’ve been playing around with this just as you mentioned @BCBUDY and I really feel your pain. It seems when I make changes I can make slight improvements but often run into slightly different problems.

It is frustrating to see others have such success and not being able to make it work and I’ve also been thinking about either trying a different medium or moving on from MC.

Since I got a soil probe and monitoring my pH more with that and runoff, I find that when things start to go bad, what often happens is the Pro-mix is plummeting in pH. And I mean down to low 5s. It doesn’t always happen but it’s a common theme. I’m currently playing around with adding some extra dolomitic lime to see if that helps later on with the pH. I could also be totally wrong on this though.

I will also say that the liquid concentrate also helps. I have more problems pop up when im mixing small batches with the dry powder. I usually make 300ml with 30g, so 10mL = 1g when I’m mixing.

I’ve also been working on fine tuning my environment. I think that also plays a part as it sort of dictates the flow and if your off the mark it changes what is taken up and what is left in the medium. While I still run into issues, it has helped.

I saw @Mañ'O'Green mention in a DWC thread that epsom salts is needed. And now he just posted in here with that info i see.

I also started making a concentrated solution of MC mixed up in a liter milk jug, then dilute that down to 500-550ppm for feeding in the watering jug.

Started tinkering with an Iphone app that has been checked out by Migro and others for the best DLI for the plants at different stages of growth. Found I was blasting too many photons on them as well. Haven't ran a full cycle using the app, and won't until fall.

I look at indoor growing like the growers holy grail, which to me is photons, medium/nutes/ and environment. Getting those in balance is me goal.

 

[BCBUDY]

Do not lower you PH.
This will cause further calcium def'c.
There is nothing wrong with doing 6.2 to 6.6 in peat with MC.


The yellow leaves is typical (on the fan leaves I suspect), are happening because of N def'c.
So up your ppms another 100.

The analogies work.

N Is the meat in the stew.
To get more N, I'm obligating you to eat more potatoes in the process, see the issue?

A work around?...

@pop22 makes his feed in a conentrate..
(like a 1/4 cup MG per gallon in a windshield washer fluid bottle).
Then adds this liquid mix to water.
Wait till the next day to adjust your PH.

He can give you the details.

I have found that feeding a little fulvic acid or ReCharge prior to flower also help with both N and P absorption.

In past grows, I thought it was the N and upped the PPM but that seemed to accelerate the problem. In 3 separate grows. It either didn't help and the leaves dying continued or would come on harder and sooner butr not only that, they'd start to claw down sharply.

I've noticed personally, I get best results, regardless of the fact that they suffer during flower, with 500-600 PPM. The leaves stay greener for longer into flower.

Based on what I'm seeing with the leaves as since upping the PPM of MC hasn't worked for me in the past, I think it's a magnesium and sulfur deficiency, just like @Mañ'O'Green has suggested. Which has lead me to feed them 100PPM of Epsom salt today, since they needed to be watered anyways.

Perhaps I'll up the PPM of the MC to 600 in along with the epsom salts at 100 for a total of 700? and I'll PH for 6.2 but will PH, wait an hour and then PH again. If I have time, I'll do it over a 24 hour period.

 

[Mañ'O'Green]

@BCBUDY you are missing the point about balanced nutrients. 3.5g MC with .5g Epsom Salt is where they are in balance. When you go with more they will be out of balance again.

 

[BCBUDY]

You need to be flexible a bit with your fertigation schedule in soil and peat of course hydro is every time. A good starting point for soil is weekly and for peat 2 times a week.

I am fairly certain I have run down the out of balance element in MC and it is not calcium it is sulfur. I am in the process of verifying this. I am willing to go out on a limb based on Bro-science. I have no sign of out of balance in my current grow as I have corrected for this. Here is the results of mathematical extrapolation from the Guaranteed Analysis.

3.5g MC v2. in one gallon of RO water. 500 - 600 PPM total is a good level for Autos. The Phosphorous is a bit too high but cannabis can tolerate up to about 100 without issues if everything else is good. Magnesium is barely in the green and sulfur is deficient.

If you add a gram of Cal-Mg the total PPM is too high and sulfur is still deficient.

If you add .5 gram of Magnesium Sulfate (Epsom Salt) You get a winning balance with the MC v2. You can use this in starting water up to about 200 PPM without calcium issues but it will be high.

Thank you sir, very good information there. I agree, I think it's a sulfur def in my case.

Couple questions;
when you say be flexible with the fertigation schedule, what do you mean? like with just plane PH'ed water or? because I feed with every watering.

And when you said I can use it in starting water up to around 200, do you mean up to around 200ppm of epsom salt or 200ppm total including MC, like 50 epsom salt, 150 MC?

sorry for the probably stupid questions, lol

 

[BCBUDY]

@BCBUDY you are missing the point about balanced nutrients. 3.5g MC with .5g Epsom Salt is where they are in balance. When you go with more they will be out of balance again.

View attachment 1321910

Ok right, so stick to around 500-550 MC (as I've done in the past with "better" success in past grows) but toss in 100PPM of epsom to round out the sulfur deficiency, right?