Cal mag; bad guess or actual knowledge? soil grows using plain tap water

[Toker1]

What is up with the over use/ over prescribing of cal-mag on this forum? I know it’s one of those formulas that is tough to really over due, but I also know it’s not the penicillin everyone claims it to be on here.
When growers see an issue, “it’s cal-mag time” with out even attempting to figure out what is really wrong in the first place. (Mostly seeing PH issues that cause this initial prescription, but no one asks about PH before Cal-Mag is tossed into the subject.)
Is this just inexperienced growers talking? Any thoughts?
we are talking soil grows, with plain tap water here. If they follow a recommended feed schedule... should be plenty of calcium and magnesium in the diet.
Why all the hype surrounding this product?
Am I missing something here?

[Canuck147]

Don't use plain water - don't use soil pre-mixed with nutes - don't use no feeding schedule - plants tell me what they want - and when. I use CaliMagic cuz it provides necessary calcium and magnesium. Also makes the plants nice and green.

[Toker1]

Since the discussion is about following a feeding schedule. When the predetermined time came, magnesium was added.
For discussion purposes, would that individual then add cal-mag in addition to, or hold off?

[Canuck147]

Hold off

[Toker1]

Totally agreed.

[Toker1]

This is a great chart example

[Colombo]

marijuana-symptoms This is from GWE that states when you have a calcium def ? you would add Cal Mag. When a grower reads what has been written in ref to this particular problem based on signs and symptoms, he adds Cal-Mag according to instructions. Considering the signs and symptoms represent 3 different problems that are the most common in growing it is used as a go to too correct any or all of those 3 problems. It's taught, learned and used. It's use is minimal as to a loss of a plant. JMO. I have learned from my time on the forum that PH, under watering /overwatering are the usual cause of the leaf problems we see and usually caused by not following a schedule. (over feed/underfeed) . Just my observation. Good Growing !!

[Toker1]

Agreed. If they follow the instructions properly, keep ph in control, and water properly most would do just fine.
I also believe, in addition to what is stated above, calcium acts as a ph buffer. This can be helpful to some growers, but not helpful when it comes to actually dealing with/diagnosing PH issues.

[George4green]

From the short time being on here I’ve noticed the same thing. Seems like a lot just jump to cal mag. Me being a new grower I always jump to PH and ppm and go from there. Like you guys said you fallow the feed chart it should have everything it needs. Normally it a PH or environmental (roots or air )

[KTM690]

Its s fine line to have a plant free of issues these days. But if ph is kept in control and a few light nutes added when needed and watering is under control all will be ok. Its hard with these crazy cross breed plants these days. Lots of challenges within each strain.

[Rwise]

After doing a lot of reading on this, here and other sites, I only use tap water. I read an article on the outdoor garden that said "only use magnesium sparingly every other year". What made me go looking was I sprayed a Bruce Banner 3 with my home mad calmag for it to show toxicity the next morning,, I dumped it BTW.

[Weed Pharma]

The problem I see, is that everyone's tap water is very different- so a blanket statement is useless!

What follows is my experience with Cal/Mag.
I started with Roots Organic Original (ROO) and tap water-only.

On the very first grow- I had a Cal/Mag deficiency at the same time I switched photo's to flower.
I would take the nutritional issues that arrived and then amend my soil for the next grow to correct whatever was found problematic on the previous grows.

After about a year (of adjusting amendments) I was able to make a simple ammended soil which allowed a reasonable (auto) grow- free of Cal/Mag issues.

At the same time, the "Blurple" light manufacturers recommended adding Cal/Mag indicating it was a result of LED's. <- consistant with my observations- so I added 3mls Cal/Mag to all photo's and long flowering autos.

I have found that strains, which have longer grow times (photo's) would show deficiencies later in the grow cycle, as well as those plants in larger containers (when I switched from 3 gallon to 5 gallon nursery pots).

I was unable to obtain a detailed water analysis, so had to go with what I could test for.
The water ppm was 40ppms from the tap- reduced to 36 ppms after filtering out chlorine,etc.
The tap water pH runs from 5.5-5.8 depending on the season.

I no longer check pH or ppms of any ROO grows- unless I have an issue (or get bored around week 5 of flower- it seems,lol)
When have checked the pH - it was around 6 and the ppms run from 300-2000ppms- but the final results are the same!

All was good until I switched to fabric pots and CoB's/ChilledLogic pucks and my Cal/Mag deficiencies have returned around mid-flower with auto's.

This is where I am now- increasing Cal/Mag to 5mls in the 5 gallon fabric pots and will have to see what develops.

I think routine run off pH testing - is also in the same catagory of "bad guess or actual knowledge?" for soil grows.

[Toker1]

So are you saying recommending cal-mag is not a good blanket statement due to lack of knowing how much calcium is already contained in the tap water?
I really have never seen someone recommend routine run off measuring on here. Only durring deficiencies. So I am not really following there. Maybe it happens, but not as often as cal mag recommendations are happening from what I am seeing.
Also, I think the point was if magnesium is already included in the diet, would you recommend cal mag to correct potential deficiencies with out first asking about PH.

[Weed Pharma]

Yes, but not only the tap water-but also, what's contained in the medium.

With regards to magnesium in the diet, would I recommend cal/mag to correct potential deficiencies? is a bit more complex: IMO

Magnesium is a mobile element lending itself to the plant where it is needed and a certain amount of repair can happen if caught soon enough.
Calcium is immobile and once the damage begins you can only hope to prevent future issues, by providing constant availabilty.

A timeline from my experiences have been Magnesium deficiency earlier and later in a grow compared to Calcium, so you could end up giving both nutrients when only one is needed- if you give Cal/Mag for magnesium issue.

When I see people state Cal/Mag it's usually a magnesium deficiency, so I'm not certain I would give Cal/Mag (depending on the stage of the grow).

Treating anything without knowing what it is - is a waste of time/money and a quick pH check helps determine if it's an uptake issue or not and I wouldn't add more Magnesium if already provided without checking the pH.

[Toker1]

Agreed. One thing to keep in mind is that not all cal mag is created equal. Some contain nitrates (which may need to be avoided in late flower) others contain sulfates... which bond to the calcium making the calcium unabsorbable for plants.

[KTM690]

Well said pharma I was ph stupid for a few grows got a good pen and paying attention pays off huge. I've posted before I've found that at week 2 to 3 of flower I give a dose of humic acid and cal mag to help break down any left overs in my soil. I found that puts the plant in a good place to finish easy. I'm all fish emulsion (shit) for veg. The rest is only molasses and liquid bat turds only 1 time a week rest ph water. I've noticed such a change in simple low nute grows might b less yield but tighter buds and way better quality. Its so interesting reading all the different ways we all grow.

[Guest]

I ordered all greenleaf nutes...they have 13% nitrogen in their cal mag. And even growing in coco.... i dont see why they did this. The base nute, megacrop, has 10% nitrogen
sounds like toxicity waiting for me lol i wont use it. I use botanicare cal mag w/ iron.

[SommerVirelli]

My experience with salt based nutrients always led me to the same problem. Never being sure of what the problem actually was; pH, deficiency, toxicity, etc. I hated fighting that crap. Went to more of a natural approach and all of those problems disappeared. In the 2 years I’ve been doing organic I’ve never had pH problem or deficiency or had to add anything like cal mag. The line I use have plenty of calcium to feed the soil.

[Toker1]

Lol. I agree to a point. I use salts, always used under the recommendation. Never PH adjust. Only time I ever experienced a deficiency (or any of the issues detailed above) is when I started PH adjusting. Now, I know that the low PH of my feed neutralizes the high PH of my tap water. So in the end, my run off is consistently 6.5 with out any adjusting necessary.

[quirk]

I use Foliage-Pro because it's levels of calcium and magnesium, in solution, in the correct ratio, negates having to use a supplement. I grow autos only and haven't used a drop of my GH Cal-Mag in 3 years. Someone will get a 'purt near full bottle at the estate sale I reckon.

[Weed Pharma]

That's a great choice! You can use just that and/or their Grow formula through the entire grow.
A little history.

Dyna-Gro would answer requests for a "bloom" nutrient by saying it wasn't needed- but the mass marketing machine had convinced people it did.

The company got so tired of answering - so it basically made up a Bloom solution do to popular beliefs which stopped the calls,lol
It is a non salt formula and can be used in all types of grows without a need to flush.

I did however, get Magnesium deficiency with my first grow of photo's.

Here is an interesting study comparing it with others: https://www.thcfarmer.com/community/...er-seen.73074/

[Toker1]

Lol. That’s funny. So producing a useless chemical was more cost effective than providing actual answers about the subject on the phone. Classy move on their part. Hope they are not too reliant on their customers purchasing their products. Lmao.

[Colombo]

Good reading ! You learn a little bit more each day in pursuit of the ultimate Grow! After my Gold finishes I will try the Earth Juices Line and see how things go. Just for the time invested in the study/test and that I use FF nutes and grow in soil. This is what makes growing so interesting !!

[George4green]

After another night of the old Cannabis research found out that amino acids goes with cal very well and helps transport into plant cells at about 1000x the rate with out. And I sure most probably all ready knew that but found me something else to spend money on. I thank I’m going with the RAW brand of it