Cal - Mag

winland · Mar 4, 2015

I do not know if this will be of help to anyone that uses lots of Calcium and magnesium but here it is for what is might be worth.

I used to be very much involved in keeping saltwater fish and corals.
My largest saltwater tank was 390 gallons.
The saltwater hobby uses lots of calcium and magnesium.

Here is a link to how to make calcium and magnesium additives that, I would think, should also work for plants.

Read carefully, and maybe someone can give some additional figures for safe use in plants.

Do-it-Yourself Two-Part
Calcium and Alkalinity Supplement System

Scuba_Steve · Mar 4, 2015

I have thought the same thing.

An easier place to obtain everything, although a bit more expensive that getting it all together yourself...

http://www.bulkreefsupply.com/brs-2-part-calcium-alkalinity-total-package-bulk.html

queequeg152 · Mar 4, 2015

ebay is going to be a much cheaper alternative.

id recommend calcium nitrate though.

Geonerd · Mar 5, 2015

Yea, calcium nitrate (or citrate) is arguably better for use on plants. Fleabay has plenty for ~$7 a pound - a near-lifetime supply.
Toss in some epsom salt or mag nitrate/citrate and you can make your own 'MagCal' equivalent for, at most, a few dollars per gallon.

I asked the local hydro shop if they sold calcium nitrate and the guy just about laughed out loud. Given the price and presumed mark-up on the WIDE variety of colorfully decorated ferts they sell (I really do appreciate the lovely artwork

), carrying a few basic chemicals would put a huge dent in their profits.

queequeg152 · Mar 5, 2015

well... its not really the same as cal mag though... being that you cannot mix calcium nitrate and magnesium sulfate. but who cares right? you mix one after the other is all.

if you are really dead set of making your own liquid concentrates... you really do need to either use calcium chloride and magnesium sulfate... or calcium nitrate and magnesium nitrate.

pre mixed concentrates are meh.

and yea the ferts are outrageously over priced...

a gallon of potassium silicate is like 100 bucks from advanced nutrients? you can get agsil for like 11 bucks an lb if i recall right.

Geonerd · Mar 5, 2015

The sulfate from the Epsom interferes with the calcium?

I think CalMag uses Ca/Mg nitrates as a base. How about using Cal and Mag acetate, those are also fairly readily available.

What would you suggest in terms of PPM and frequency of use with container (soil) peppers?

queequeg152 · Mar 5, 2015

most cal mags use calcium nitrate and magnesium nitrate from what i recall.

OR calcium chloride and magnesium sulfate.

fish aquariums are different... being that fish do not tolerate much nitrate( right?), so they use chloride salts usually.

calcium and sulfate in great concentrations... such as in a bottle of concentrated fertilizer will precipitate out forming insoluble calcium sulfate.

regarding ppms... its impossible to say if you are using an organic soil, as organic soils may alrady have plenty of nitrogen via ammonia or urea.

i grow in a soilless mix and my nutrient profile is 190mg/l nitrate and 170 mg/l calcium.
i guess if you wanted to be safe... cut that in half and see what happens.

Scuba_Steve · Mar 5, 2015

queequeg152 said:
fish aquariums are different... being that fish do not tolerate much nitrate( right?), so they use chloride salts usually.

Fish can handle nitrate fairly well. Nitrite is another story...

Corals on the other hand can not handle nitrate, and that is what the cal/alk/mag is intended for. Hard corals build their skeleton out of calcium.