Recommended calcium supplements?

[Jayfar]

My tap water tested at 31.1 ppm Ca and 9.28 ppm Magnesium. I'm not sure whether that is sufficient or not. I've been alternating, sometimes combining, MSU well water formula (w/o Ca) and K-Lite (which contains 10% Ca). I aim for about 100 ppm Nitrogen at each watering (frequency varies per pot size and medium).

I have been using epsom salts, usually at least monthly, for Mg and Sulphur. What's a good supplement for Ca, if I need it? I see Botanicare Cal-Mag Plus listed on Amazon. Is anyone using this? Is there a cheaper product that will supply just the Calcium in a soluble form that my orchids can use? I see FirstRays has Calcium Nitrate for example, listed for soaking CHC to help remove salt, but I don't know what rate to apply it at as a supplement or whether it's a good form of Ca for root absorption versus Calcium Carbonate.

I've sometimes read of crushed oyster shells or egg shells used for calcium, but on the other hand, I've also read that those don't provide a soluble or useable form of calcium.

Thanks.

[AnonYMouse]

I have the General Hydroponics CaMg+. If you were closer (like driving distance), I'd just pour you some.

I got it for this chlorosis issue I had. I don't know what to make of the product since I don't have any basis for comparison (one plant with a problem makes for a bad study stat) and I'm really bad about consistency. I've used it on other plants when it occurred to me without any ill effects.

Probably not much help.

BTW, that plant got better for awhile but recently succumbed to severe and rapid chlorosis.

[Jayfar]

Thanks AnonYMouse. A lot of good info in and linked from that thread you linked.

[Discus]

IIRC you want to ideally dose with both calcium and magnesium at the same time, so one of the many cal-mag type formulations would be your best bet. Depending on your regime, you may like to simply "boost" your cal-mag doses by swapping one of your regular MSU fertigations with a cal-mag one. (e.g. something like MSU-calmag-MSU-flush on a monthly once a week fertilisation cycle).

[Jayfar]

Originally Posted by Discus

IIRC you want to ideally dose with both calcium and magnesium at the same time, so one of the many cal-mag type formulations would be your best bet. Depending on your regime, you may like to simply "boost" your cal-mag doses by swapping one of your regular MSU fertigations with a cal-mag one. (e.g. something like MSU-calmag-MSU-flush on a monthly once a week fertilisation cycle).

Thanks. I've already ordered a quart of the Cal-Mag Plus (which also includes iron). I definitely need it with the MSU well water formulation, since my tap water is low on those. Maybe not so much with the K-lite, which I see is 12.9% N, 1.3% P, 1.3% K, 10% Ca, 3% Mg and 0.115% Fe.

[tucker85]

All the hydroponics supplements are expensive unfortunately. You don't need to use very much so they do last a long time. I've been using one called MagiCal by Technaflora for about a year now. It's hard to say if it's being effective but one thing I've noticed is that I haven't had bud drop problems since I've been using it. I used to have a terrible time with bud drop. I use MagiCal at the dosage on the label (1 tsp./gal), every two weeks.

[Jayfar]

Originally Posted by tucker85

All the hydroponics supplements are expensive unfortunately. You don't need to use very much so they do last a long time. I've been using one called MagiCal by Technaflora for about a year now. It's hard to say if it's being effective but one thing I've noticed is that I haven't had bud drop problems since I've been using it. I used to have a terrible time with bud drop. I use MagiCal at the dosage on the label (1 tsp./gal), every two weeks.

Thanks. It looks like MagiCal and Cal-Mag Plus are pretty close to the same formulation.

Cal-Mag Plus:
Guaranteed Analysis:
Total Nitrogen (N): 2.0%,
2.0% Nitrate Nitrogen
Calcium (Ca): 3.2%
Magnesium (Mg): 1.2%,
1.2% Water Soluble Magnesium (Mg)
Iron (Fe): 0.1%,
0.1% Chelated Iron (Fe)
Derived from: Calcium Nitrate, Magnesium Nitrate, Iron EDTA

MagiCal:
Total Nitrogen (N): 2.0%,
2.0% Nitrate Nitrogen
Calcium (Ca): 3.25%
Magnesium (Mg): 1.2%
Iron (Fe): 0.11%,
0.11% Chelated Iron (Fe)

[tucker85]

I agree. I think the most important thing is that these products are chelated minerals which are more readily available to the orchid and that the magnesium and calcium are used together. I've read that they're absorbed better when used together.

[Jayfar]

Originally Posted by tucker85

I agree. I think the most important thing is that these products are chelated minerals which are more readily available to the orchid and that the magnesium and calcium are used together. I've read that they're absorbed better when used together.

Well, for the metals anyway, i.e. the chelated Iron.

Chelation - Wikipedia, the free encyclopedia

Fertilizers
Metal chelate compounds are common components of fertilizers to provide micronutrients. These micronutrients (manganese, iron, zinc, copper - are required for the overall health of the plants. Most fertilizers contain phosphate salts that, in the absence of chelating agents, typically convert these metal ions into insoluble solids that are of no nutritional value to the plants. EDTA is the typical chelating agent for this purpose.