Ca + Mg question

[Slobo]

Thanks Jade

The info in my last post is from the local water utility department. The hardens is specified as 81 ppm which translates into 4.74 GPG (grains per gallon). This puts this water in the low moderately hard water, but I really don't know what effect if any this fact will have on my plants.

Slobo

[euplusia]

Calcium is most important to produce hardier and more resistant cell walls, thus making the plant more resistant against stress of temperature and infections,especially when in active growth. The calcium in well water is CaCO3, Calcium Carbonate. This is useless for the orchids, they cannot take it, it is eventually harmful. Calcium for orchids in fertilizer should be Calcium nitrate, as far as I know.

[Ray]

You'll note that the water report hardness and alkalinity "as" CaCO3. In reality, it is likely a combination of calcium-, magnesium-, and iron carbonates.

Euplusia is correct that calcium carbonate is not very soluble, but the stuff that IS in solution is an absorbable hydrolyzed ion of calcium, not the carbonate as a molecule.

Your water analysis shows 20 ppm Ca and 6 ppm Mg. If we trust the MSU RO formula as a good standard to use, then when mixed with pure water at the 125 ppm N concentration, the final solution will contain about 75 ppm Ca and 18 ppm Mg.

Personally, I think your levels are fine, but supplementing a bit cannot hurt.

[Slobo]

Euplusia,

As a novice to the orchid growing hobby, I'm very eager to learn as much as I can. Your information is very valuable to me. Thank you.

Ray,

This is exactly what I want to hear, the affect of this water on my plants and if I need to do anything to make it better if need to be.
I read info on your site several times. Great site. That is where a learnt how to calculate ppm N. Whenever I find any info on the web I always end up on your site looking for confirmation. Thank you.

Slobo

[mattryan]

Everytime I have read any literature about adding epsom salts, it has always said not to put them into same solution as your fertilizer. Now the only thing that I can find is that they're might be an adverse reaction between them (epsom salts) and your fertilizer. Just to be on the safe side I always do them separately. But I only add epsom salts once per month. Others might be given them more often than I am.

Cheryl

[Slobo]

Thanks Cheryl.

[euplusia]

The question about Calcium supply is so essential for healthy resistant strong growing roots and plants that I go a bit deeper.
Calcium is a positive or Kation, Ca2+. It makes a chemical reaction with the negative or Anions Phosphat (PO4)3- and Sulfat (SO4)2- and (HSO4)-. The results are Calciumdihydrogenphosphat Ca(H2PO4)2 and Calciumhydrogenphosphat CaHPO4 and Calciumphosphat Ca3(PO4)2 and Calciunsulfat CaSO4.
All these products are nearly not soluble in water. So they are of no use for your plants. This is the reason why you should not mix together Calcium and Phosphor.
Overmore does Calcium bind trace elements.
On the other hand Calcium is needed just in time for growth. It cannot be stored in plants and is washed out easily. That's the reason why I recommended the soluble Calciumnitrat Ca(NO3)2.
If you are not afraid of having a look on a German site, here is a link to part 1 and 2 called "Easy Fertilizing" at OrchideenFreunde.eu. Part 3 is not published yet.

Düngen leicht gemacht, 1. Teil - OrchideenFreunde.eu

Düngen leicht gemacht, 2. Teil - OrchideenFreunde.eu

I love your thorough mindful question.

[Slobo]

Thanks euplusia,

Great information. I visited the sites you provided links to, and I'm so ashamed to admit that I don't understand the language completely. After all I learnt German when I was in junior high school. Wow that was like more than 50 years ago.

Thanks,

Slobo