# Calcium supplementation for multis



## orcoholic (Jan 24, 2010)

I've read that most multiflorals like some type of calcium supplementation. My questions are:

1. Do you need to supplement if using MSO RO fertilizer in RO water?

2. If yes, what is best to supplement with - dolomite or oyster shell? Both of these are available to me and are very reasonably priced.

3. When is best time to use it?

Thanks.


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## Ernie (Jan 24, 2010)

1) probably not, but we do because we don't use exclusively MSU ferts

2) dolomitic lime provides both Ca and Mg, but most formulations I've seen flow through open orchid mixes pretty fast (the pellets that explode, etc). So we use oyster shell for Ca and apply Mg as epsom salts irregularly as foliar feed and root drench with normal watering about 1/2-1 tsp per gallon. 

3) Whenever you remember. Oyster shell is nice because you can see it. We top dress at repotting and add as needed. About a teaspoon per 3-4" pot works. Epsom salts again sporadically. Of course, it's best to have nutrients available when plants are actually growing which is determined by your growing, region of the world, etc. 

-Ernie


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## cnycharles (Jan 24, 2010)

there is also a product called 'flowable lime or limestone'. I don't remember the brand name, usually comes in one or 2.5 gallon containers. I can look tomorrow if we have any around. It's made to be used through irrigation systems if necessary (meaning not just through a hose). don't know if it has any magnesium, but epsom salts are very available and easily used


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## Rick (Jan 25, 2010)

Many multifloral species as well as many of the Brachy's and Parvis are found in association with limestone.

Jumping to "a physiological need for calcium" I think is quite a stretch.

Limestone by definition has a minimum of 50% calcite (calcium carbonate). Some limestone areas do have higher percentages of calcite, but often you are over various grades of dolomitic limestone, which is closer to 50/50 calcite and magnesium carbonate. There are often small amounts of phosphate bearing rock in limestone areas and many phosphate mines are located in karst limestone areas too.

So along with Ca, there is usually significant amounts of magnesium and phosphate available to calciolus paphs. Also the pH of the substrate is buffered to stay within the optimal nutrient bioavailability range of 5.5 to 7.5.

I'm not sure why everyone focuses on the Calcium. So I suggest you take your pick as to the benifits of adding calcerious materials to your potting mixes:

pH support, Ca, Mg, PO4. 

Unless your turn over your potting mixes frequently (at least once a year), or have excesses of certain metals in your water supply. Then additions of oyster shell, limestone, bonemeal and epsom salts make good sense from a good pot managment or general horticultural standpoint.

Ernie brought up some great points on the use of these too.


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## Ray (Jan 26, 2010)

Got a question for the pros: As one who used to have a lot of African cichlid tanks, I used to use dolomite as the bottom cover. It was available in 1/4"-3/8" pieces. Might that be a reasonable additive?


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## cnycharles (Jan 26, 2010)

hmmm, there is a slight need for calcium all the time for plants, since it isn't translocated from one plant storage zone to the next. meaning that if there is new growth or an ongoing need, more must be taken up into the plant somehow. nitrogen is something that can be 'borrowed' from one spot to another (why one reason bottom leaves turn yellow when new growth), calcium doesn't move that way.

wanted to mention to anyone interested that the 'liquid flowable limestone' I was mentioning from work is actually liquid dolomitic limestone manufactured by the cleary corporation, so has good amounts of both calcium and magnesium. they market it mostly to be used as pH control in nursery situations and less prominently as a plant nutrient. 
... seems like dolomitic gravel would be as good as anything though I am not knowledgeable about how much more or less 'reactive' or able to affect pH and all in that state in a pot than anything else. I've used some in other pots, and have some in pots that have armeniacum and micranthum. armeniacums are moving positively if the mealybugs would leave them alone, but micranthum as usual isn't doing much

(link to 2 page pdf showing label of flowable limestone http://www.clearychemical.com/support/label/4902SL.pdf )


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## Eric Muehlbauer (Jan 26, 2010)

I've been using Espoma long acting garden lime....its actually pelleted dolomite. The little balls are about 3-4mm across.....so far it hasn't hurt anything, so I'll continue to use it.


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## Rick (Jan 26, 2010)

Ray said:


> Got a question for the pros: As one who used to have a lot of African cichlid tanks, I used to use dolomite as the bottom cover. It was available in 1/4"-3/8" pieces. Might that be a reasonable additive?



yes

If you could beat it up to 1/8" or less that would be better I think.


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## Rick (Jan 27, 2010)

cnycharles said:


> hmmm, there is a slight need for calcium all the time for plants, since it isn't translocated from one plant storage zone to the next. meaning that if there is new growth or an ongoing need, more must be taken up into the plant somehow. nitrogen is something that can be 'borrowed' from one spot to another (why one reason bottom leaves turn yellow when new growth), calcium doesn't move that way.



http://www.ladyslipper.com/minnut.htm

Check out this link from the Antec reading room. According to this, calcium and magnesium are the 6th and 7th most common elements in orchid tissues, and at roughly 1/8 the amount of nitrogen in plant tissues. Once you take out the water and carbon, they are the 3rd and 4th most common elements I think this counts for a bit more than "slight".

I have seen some similar analysis of other plant tissues (namely bamboo) that actually have higher amounts of magnesium than calcium in their tissues, and some scattered data on paphs that shows a wide amount of variability (even for the same species under different culture conditions). So I'm sure there is tons of slop in this system.

You are correct Charles that Ca does not translocate readily through the plant, but magnesium does move around readily.


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## Jimsox (Jan 27, 2010)

Ray said:


> Got a question for the pros: As one who used to have a lot of African cichlid tanks, I used to use dolomite as the bottom cover. It was available in 1/4"-3/8" pieces. Might that be a reasonable additive?



The water and droppings from the bottom of the tank is an awesome additive as well.....yes fish poop!!!


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## TyroneGenade (Jan 27, 2010)

Hi,

I am wondering what you may think about the following mix for paphs:
lime stone
leaf mulch

My reasoning: Paph are often found growing on limestone and normally in leaf litter of some sort. Why I would like to go with stone is because most of my orchids are potted in stone (with a some bits of rock wool or sphagnum to hold moisture). For watering purposes I would like to use the same rocky mix throughout my collection. This will simplify my watering regime.

Thoughts?


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## Ernie (Jan 27, 2010)

TyroneGenade said:


> Hi,
> 
> I am wondering what you may think about the following mix for paphs:
> lime stone
> ...



Sure, i think this would work if you want it to. From what I've read and from discussions here, Paph roots ramble through the upper layers of leaf litter over a substrate of limestone (as appropriate) more or less horizontally- they don't really send roots deep vertically "into" the rock. Not sure how deep that litter layer is. I think if you did this well drained mix and watered frequently, you'd be fine and your plants would be happy. Also sounds like a cheap mix, a bonus. 

-Ernie


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## gonewild (Jan 27, 2010)

The problem with leaf litter is that it will decompose quickly. This is the reason for use of bark or chc in a mix. rather than leaf litter look for an organic material with the same basic properties and that won't decay so fast.


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## TyroneGenade (Jan 28, 2010)

Thanks for the comments, Ernie and Lance. I want a quick draining mix and I don't mind repotting frequently. I've noticed that regardless of the potting medium the roots tend to run horizontal and then down the side of the pot in any case. About an organic alternative... Hmmm. I want the minerals in the plant leaves which I think are not in coco husk nor so much in bark or peat. Any suggestions?

Lance, you know Brian Perkins?


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## gonewild (Jan 28, 2010)

TyroneGenade said:


> Lance, you know Brian Perkins?



Yes I know Brian.
Brian has restarted our Peruvian Aquarium operation. In fact he is down there now to guide a couple on an orchid viewing trip.


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## cnycharles (Jan 28, 2010)

TyroneGenade said:


> About an organic alternative... Hmmm. I want the minerals in the plant leaves which I think are not in coco husk nor so much in bark or peat. Any suggestions?



though I haven't made any myself (not having a yard and all for doing compost or storing the equipment), I know people who make 'compost tea' concentrate and then dilute it to use for their plants (not necessarily orchids, but can be used just the same). you could make some tea from the leaves and such that you'd like some of the minerals from, and use it with your orchids (just a thought, don't know if the mineral component in the leaf solids would necessarily break down and enter into solution, though it seems like compost is pretty, um, soft when it's all said and done...


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## TyroneGenade (Jan 29, 2010)

gonewild said:


> Yes I know Brian.
> Brian has restarted our Peruvian Aquarium operation. In fact he is down there now to guide a couple on an orchid viewing trip.



What a small world, or is it that fish folks and orchid folks seem to have a common interest?

Charles, maybe it is time I get a worm farm.


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