How to know if you should be using CalMag

[YetAnotherOrchidNut]

Originally Posted by camille1585

My chemistry knowledge is rather limited, but I thought that calcium was present in different forms in water, both soluble and insoluble, not not just insoluble CaCO3? Unfortunately the water analysis rarely gives this information.

Hrm. I think however waternet does. It says average calcium is 41.35mg/l, it says average "carbonate" is <5mg/l. I think "Carbonaat" is carbonate anyway, and i assume that means calcium carbonate. I dont know.

At the very least this question has made me read more chemistry papers than I have since university. :-)

[camille1585]

Originally Posted by YetAnotherOrchidNut

Hrm. I think however waternet does. It says average calcium is 41.35mg/l, it says average "carbonate" is <5mg/l. I think "Carbonaat" is carbonate anyway, and i assume that means calcium carbonate. I dont know.

At the very least this question has made me read more chemistry papers than I have since university. :-)

Carbonate is CO3- ,so I don't think that line is referring to calcium carbonate...

I did read something interesting on the Vitens website (my water company)

"Het is namelijk zo dat kalk pas ontstaat als calcium een reactie aangaat met carbonaat. Pas dan krijg je calciumcarbonaat en dat noemen we kalk. Die reactie ontstaat onder andere als je water verwarmt. Bijvoorbeeld als je onder de douche staat. Vandaar dat dit ook de plek is waar je vaak last hebt van kalkaanslag.

Van hard naar zacht(er) water
Drinkwaterbedrijven kunnen water ook zacht maken. Op sommige locaties heeft Vitens een onthardingsinstallatie. In deze installatie zorgen we ervoor dat calcium en magnesium kalk worden. Die kalk halen we vervolgens weer uit het water. Maar we kunnen niet alle kalk uit het water halen. De wet bepaalt dat drinkwaterbedrijven niet al het calcium en magnesium uit het water mogen halen (minimale hardheid van 5,6 dH). Dus krijg je met zacht water, toch nog wat kalkaanslag."
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I don't know how good your dutch is but the main points are 1) calcium carbonate is mostly formed when heating the water, where Ca and carbonate bind. 2) Water companies can lower the amount of Ca and Mg in hard water by intentionally creating the carbonate forms of both, and then filtering it out. However they legally can't remove all Ca and Mg, the legal minimum hardness after this procedure is 5,6 dH.

[Leafmite]

If you can find a local nursery or orchid society, they might be able to guide you as they will have the same water as you do. I tend to err on the side of overkill when it comes to Calcium because I lost quite a few of my Cattleyas many, many years ago due to Calcium deficiency allowing black rot to run through and kill most of them. Lesson learned.

Not all orchids need great amounts of Calcium. Some Paphs will need it but those in my orchid society solved that by using crushed oyster shell every spring. If you put your orchids outside and have heavy rains, you might need to have a slow release form of Calcium during periods of rapid growth if you have Cattleyas and Angraecums.

There are some orchids/plants that prefer very little Calcium (all plants need some to help build their cell walls...my Carnivorous plants might have sensitive roots but they get it through the plants they catch). Even the organic fertilizer I use for my lower pH plants has Calcium.

[SADE2020]

Sorry.. I am lost, what is MSU?

And, PH 8.0 with all plants; including Cool2Warm Plants ? Masdies and Dracula?

[Leafmite]

MSU Fertilizer: Michigan State University, a college in Michigan, USA developed what many felt was the perfect fertilizer formulation and it was adapted for orchids. It has many micro-nutrients and comes in formulas for rain/distilled water and tap water.

[BobcatJohnson]

First, please forgive me for making fun of your typo...

Originally Posted by Leafmite

(all plants need some to help build their cell walls...my Carnivorous plants might have sensitive roots but they get it through the plants they catch)

Where did you find vegan carnivorous plants? Wouldn't those be Herbivorous plants?

[Leafmite]

It actually took me a few moments to find the typo.

[SADE2020]

Originally Posted by Leafmite

MSU Fertilizer: Michigan State University, a college in Michigan, USA developed what many felt was the perfect fertilizer formulation and it was adapted for orchids. It has many micro-nutrients and comes in formulas for rain/distilled water and tap water.

Thanks. The so called Rainmix in Europe. Got it!!