Fertilizer Ingredients

[LFC25]

Anyone using Baby Bio Orchid food? The label stated active ingredients NPK 5.3:2.2:0.8.

How to interpret these numbers? I only know a bag of 10-10-10 fertilizer contains 10% nitrogen, 10% phosphate and 10% potassium.

[Bulbopedilum]

They are ratios.
If I am not mistaken then it means that
61% of it is N
25.5% is P
9 % is K
But that doesn't sum up into 100% so I'm a bit confused.

[Ray]

I cannot speak for the entire globe on this, but the standard in the US is that the numbers are weight percent elemental nitrogen, phosphorus as P2O5 and potassium as K2O.

So each kilogram of that fertilizer formula will have
53 g N
22 g P2O5 (x 0.83=18 g P)
8 g K2O (x 0.44=3.5 g K)

If your country uses straight elemental conventions, ignore those factors.

[LFC25]

Originally Posted by Ray

I cannot speak for the entire globe on this, but the standard in the US is that the numbers are weight percent elemental nitrogen, phosphorus as P2O5 and potassium as K2O.

So each kilogram of that fertilizer formula will have
53 g N
22 g P2O5 (x 0.83=18 g P)
8 g K2O (x 0.44=3.5 g K)

If your country uses straight elemental conventions, ignore those factors.

So how to translate these numbers into percentage?

[estación seca]

I would first find out what the fertilizer numbering convention is in your country. While looking up that you will learn how to calculate the percentages. What Ray said, above, is true for the US, but I have read it is different in other countries.

And another way of looking at it is that the percentages don't matter. Most orchids use very little fertilizer. There is a nitrogen calculator on Ray's Web site, in his signature line. Most people use a low concentration of nitrogen, which varies with how often they water. I use about 25 parts per million nitrogen with almost every watering for many of my plants.

[Ray]

Originally Posted by LFC25

So how to translate these numbers into percentage?

They ARE percentages. 5.3 = 5.3 weight percent.

If the P & K are expressed as oxides, it should say to on the label: "P, expressed as P2O5", for example.

[LFC25]

Yes, they are expressed as oxides.

Some extra information I got:

UK Statutory Fertiliser Declaration Compound Fluid Fertilizer 5.3-2.2-0.85 Nitrogen (N) 5.3% Phosphorus Pentoxide (P2O5) total 2.2% (P 0.95%) Soluble in water 2.2% (P 0.95%) Potassium Oxide (K20) 0.85% (K 0.7%)

---------- Post added at 09:13 PM ---------- Previous post was at 09:11 PM ----------

Originally Posted by Ray

They ARE percentages. 5.3 = 5.3 weight percent.

If the P & K are expressed as oxides, it should say to on the label: "P, expressed as P2O5", for example.

I'm confused. Do you mean there is only 5.3% of nitrogen in the bottle?

[Ray]

Originally Posted by LFC25

I'm confused. Do you mean there is only 5.3% of nitrogen in the bottle?

That is correct.

In anticipation of "what else is in there?", you have to rely on the manufacturer listing the contents on the label, and understand that they are only required to list certain ones, and may only list the nutrient cations, rather than the whole molecules, in the analysis. There may be another segment of the label telling you what actual chemicals those nutrient ions are derived from.

Also understand that in order to match the nitrogen content of a 10.6%N formula in the final solution, you simply need to add twice as much.

[LFC25]

Thanks all for the responses. Will email to the manufacturer for the type of nitrogen inside the bottle.