Calcium Supplementation

[Carper]

Hi Everyone,

I feed my multigrowth paphs and phrags with the MSU fert 13-3-15 and have had very good success. I have managed to work out over the last year or so what strength I can feed at which is about 80 ppm Nitrogen without any negative effects. This matches my conditions in the UK which are not as favourable as yours I'm afraid, ie less sun etc. I have been supplementing magnesium in the form of epsom salts which basically increases it by approx 50% from whats in the MSU. The plants certainly look healthier and greener. I am now considering an increase in calcium also by approx 50% to the MSU in the form of calcium nitrate. Any thoughts or recommendations, negatives or positives would be very helpful.

Thanks

Gary
UK

 

[Ray]

I use CaNO3 as a medium presoak, but sell a great deal of it to growers who use it as a fertilizer supplement.

I have heard some concerns about it boosting the nitrogen too much, but as it is a 15.5-0-0-19Ca product, in order to increase the calcium by 50% over that of the MSU formula (2% to 3%), you'd only be adding about 3/4% additional N, so I doubt it would be an issue.

 

[NYEric]

Increase your lighting.

 

[Brabantia]

Increase your lighting.

Did you know the energy cost in Europa?

 

[Brabantia]

Why do you want increase the calcium and magnesium content in your fertilyser solution? At 85 ppm N you have around 650 mgr/L of fertilyser in your solution. Having 8% Ca and 13% Mg in the powder fertilyser you have 52 mgr/L Ca and 13 mgr/L Mg. From the Wellenstein's paper (AnTec Laboratory) you are in the range they recommend for slipper orchids. I agree at the lower limit for Mg.

 

[Rick]

Since you are presently seeing some positive effects, I'd hold off on any more increases and run what you are doing for a season and see what happens. You may want to back off on stuff rather than add more.

Unless you are starting with an RO water, your tap water already has more Ca than Mg in it, so I wouldn't spike any more Ca (which will fight with the boosted Mg anyway).

 

[Brabantia]

Why do you want increase the calcium and magnesium content in your fertilyser solution? At 85 ppm N you have around 650 mgr/L of fertilyser in your solution. Having 8% Ca and 13% Mg in the powder fertilyser you have 52 mgr/L Ca and 13 mgr/L Mg. From the Wellenstein's paper (AnTec Laboratory) you are in the range they recommend for slipper orchids. I agree at the lower limit for Mg.

Correction
Sorry, 2.6% of magnesium (Mg) in MSU not 13%. Your content in Mg is thus: 16.9 mgr/L. My previous conclusion remains valid.

 

[Masdyman]

I am not sure about this, i don't know where a stand as in one hand i think, why supplement when you already have a good feeding regime so why bother with the extra cost/hassle. In the other hand i think maybe it would be beneficial to the plants. At the moment my plants are growing well so i won't be supplementing, i do add Calcium /Mg as a pre soak to CHC.

 

[Rick]

An old horticulture standard for supplementation is bonemeal.

Lots of Ca and Phosphate (instead of nitrogen) in a time release top dress.:wink:

 

[Eric Muehlbauer]

I had read somewhere that modern bonemeal is too highly processed...and that the old fashioned bone meal had far more nutrients.

 

[Rick]

I had read somewhere that modern bonemeal is too highly processed...and that the old fashioned bone meal had far more nutrients.

There was some worry about mad cow disease, so they cooked the snot out of it. I've been using pig bonemeal instead, which hasn't been processed quite as much.

 

[Eric Muehlbauer]

I had read about the overprocessing even before mad cow...but I do remember bone meal being a concern when mad cow was at its worst. Do they make fish bonemeal?

 

[Brian Monk]

Cooking bone meal won't significantly alter its mineral content. Other organic compounds, maybe, but as I understand, bonemeal is provided mostly for phosphorous. Potash used to be made simply by burning bones.

 

[likespaphs]

any suggestions for quantity of oyster shell to put in 2 inch or 4 inch pots?

 

[goldenrose]

I don't know that there's a specific dose, I just sprinkle a spoonful over the top.

 

[Rick]

I don't know that there's a specific dose, I just sprinkle a spoonful over the top.

That's probably as good as any other measure, and I've done that too.

Oyster shell ends up working very much like bone meal after its sucked up excess P for a while, and then when the biomass and orchids latch into it it's like a slow P release.

 

[Carper]

I do start with RO water which has a reading of about 40 m/s, therefore you know what feed your putting in is what the plant is getting. After 12 months of using the MSU 13-3-15 regularly, virtually all my plants look and feel healthier, from leaves to roots. I am looking forward to see how they will flower when the spring returns and there are good signs at present. There seems to be a good number of paphs that look as though they are preparing to throw up spikes. Some are already in the process. As my water feed has now frozen to the ghouse, I am having to use tap water anyway, which is reading at 700 m/s so I am making up only a very weak feed solution. The calcium will be already at a higher level, so obviously am not adding anything extra at the moment.

Gary
UK

 

[likespaphs]

any thoughts as to whether to use fine (like flour) or chunkier oyster shell?

 

[Erythrone]

Because of its fine particle size and therefore its greater surface area, the calcium supplied by "oyster shell flour" should be readily available... It happens if we use fine lime instead of "granular" lime in the garden. It must be the same for other "flours".

But.... I would avoid "flour" since the finer stuff will go away with water. Orchid meadia with bark, leca, etc. do not retain very fine stuff well!

 

[Ray]

OK. Science nerd warning:

Just how "readily available" is Ca from oyster shell? It's not the most soluble material known to mankind.