I used to have to supplement my Canna nutes with magnesium regularly. I would get the slight yellow zebra stripes on my leaves and used to use epsom salts for the Mg I was lacking.
I have never uderstood why companies don't include alot of the trace minerals (molybendum, magnesium, copper, iron, magnesium, calcium...)
that plants seem to need or lack at some point in their growth.
It can be very confusing trying to figure out which things your plant is recieving too much of, or not enough.
I switched ferts four months ago and have never looked back.
The one I use has all the trace minerals in it and have never had to supplement, or change a thing.
I use a brand called Jacks Classic Bloom Booster. This company makes other nutes as well, that's just what I use for blooming.
As far as calcium, I am going to be honest.
Until I stated viewing these threads, I never heard of a calcium deffienciency nor have I ever seen one.
I am still trying to find the scientific evedence that it makes a difference.
It is a lot like Phing your water.
Can EXTREMELY high or low PH levels affect your plants ability to absorb nutrients? I'm sure it can, however most of us on public municiple water systems will never see Ph spikes that reach anywhere close to harmfull levels. I have been growing vegetables in my garden and many 1000s of houseplants in my life and ALL have been watered directly from the hose. (chlorine is a naturally occuring mineral as well, but thats another argument)
Do you think farmers PH their water? You have to discern for yourself which statements are scientifically proven facts, myths or just common practices people have adopted because they heard it before. Try and find a calcium deffiencency on a chart. Of course Cal Mag works because magnesium defficiency is common and this corrects that as well.
It certainly doesn't hurt to adjust your PH, I just haven't done so in almost a year and have noticed absolutely no difference.
Here are the specs for the nutes that work for me. (notice there is no calcium listed?) Never used anything else since I switched. I'm no scientist, I just have never noticed I needed this.(and yes I get great yields of 4 oz. per plant average)[h=2]Guaranteed Analysis[/h]
[TABLE="width: 100%"]
[TR]
[TD="width: 99%"]Total Nitrogen (N)[/TD]
[TD="width: 57, align: right"]10%[/TD]
[/TR]
[TR]
[TD="colspan: 2"]5% Ammoniacal Nitrogen[/TD]
[/TR]
[TR]
[TD="colspan: 2"]5% Nitrate Nitrogen[/TD]
[/TR]
[TR]
[TD="width: 99%"]Available Phosphate (P[SUB]2[/SUB]O[SUB]5[/SUB])[/TD]
[TD="align: right"]30%[/TD]
[/TR]
[TR]
[TD="width: 99%"]Soluble Potash (K[SUB]2[/SUB]O)[/TD]
[TD="align: right"]20%[/TD]
[/TR]
[TR]
[TD="width: 99%"]Magnesium (Mg)[/TD]
[TD="align: right"]0.50%[/TD]
[/TR]
[TR]
[TD="colspan: 2"]0.50% Water Soluble Magnesium (Mg)[/TD]
[/TR]
[TR]
[TD="width: 99%"]Boron (B)[/TD]
[TD="align: right"]0.02%[/TD]
[/TR]
[TR]
[TD="width: 99%"]Copper (Cu)[/TD]
[TD="align: right"]0.05%[/TD]
[/TR]
[TR]
[TD="colspan: 2"]0.05% Chelated Copper (Cu)[/TD]
[/TR]
[TR]
[TD="width: 99%"]Iron (Fe)[/TD]
[TD="align: right"]0.10%[/TD]
[/TR]
[TR]
[TD="colspan: 2"]0.10% Chelated Iron (Fe)[/TD]
[/TR]
[TR]
[TD="width: 99%"]Manganese (Mn)[/TD]
[TD="align: right"]0.05%[/TD]
[/TR]
[TR]
[TD="colspan: 2"]0.05% Chelated Manganese (Mn)[/TD]
[/TR]
[TR]
[TD="width: 99%"]Molybdenum (Mo)[/TD]
[TD="align: right"]0.0009%[/TD]
[/TR]
[TR]
[TD="width: 99%"]Zinc (Zn)[/TD]
[TD="align: right"]0.05%[/TD]
[/TR]
[TR]
[TD="colspan: 2"]0.05% Chelated Zinc (Zn)[/TD]
[/TR]
[/TABLE]