Organic potassium without chloride: how much chloride each source adds
The cheapest potassium in the world is muriate of potash, and every kilo of K₂O it delivers puts roughly 0.770 kg of chloride into the soil. That is irrelevant in a cereal and ruinous in an avocado. This page does not argue that potassium matters — it does. It answers the one question that changes a purchase: how much chloride each source forces you to apply per unit of potassium. With chloride measured at an accredited laboratory, not declared.
0,000
kg of chloride per kg of K₂O from muriate of potash, the standard source
0,000
from BALANCE 6-3-18: fourteen times less chloride for the same unit of potassium
0
potassium sources in the range with chloride measured at an accredited lab
Chloride entering per kg of K₂O
Shorter is better. The grey bar is muriate of potash, the market's standard source, shown as a reference.
| Potassium source | kg Cl per kg K₂O | Versus muriate of potash |
|---|---|---|
| BALANCE 6-3-18 | 0,052 kg Cl / kg K₂O | 14,7× menos |
| BALANCE 7-7-7 | 0,111 kg Cl / kg K₂O | 7,0× menos |
| K-FLOW 20 | 0,139 kg Cl / kg K₂O | 5,5× menos |
| PK-FLOW 20 | 0,141 kg Cl / kg K₂O | 5,5× menos |
| FULVEX 50S | 0,468 kg Cl / kg K₂O | 1,6× menos |
| Cloruro potásico (KCl) | 0,767 kg Cl / kg K₂O | — |
Why the right question is not how much potassium, but what comes with it
With potassium the nutrient is rarely the problem: the companion ion is. The dominant source worldwide is muriate of potash, around 60 % K₂O and 46 % chloride. Applying it means that for every kilo of K₂O you place, you are placing roughly 0.770 kg of chloride. That is the figure to compare — not the chloride percentage on the bag.
In cereal, beet or maize chloride rarely matters. In avocado, citrus, blueberry, strawberry or vine it is the first thing that limits: it accumulates at the leaf margin, competes with nitrate for the same root transporters and raises the conductivity of the soil solution. The same fertiliser can therefore be right on one farm and wrong on the next.
Sulphate of potash is not the only alternative
Sulphate of potash adds zero chloride, which is why it is the classic answer in sensitive crops. But it acidifies and adds sulphur, which is not always what is needed. The sources in this table sit between the two extremes, with chloride measured rather than assumed.
«Chloride-free» on a datasheet is not an analysis
It is a phrase, and it is written lightly in this market. The only thing that demonstrates it is a laboratory test with a stated method. We publish ours with the method, the detection limit, and the references we have not tested yet.
Organic certification says nothing about chloride
They are independent: certification attests to the origin of the raw materials and the process, not the chloride content. This very catalogue contains certified references with measured chloride as high as 5.62 %.
pH also decides the mix
K-FLOW 20 has pH 12.52 and PK-FLOW 20 pH 7.49. A pH that high conditions tank loading order and what it can be mixed with. It is on each product datasheet and in the compatibility tool.
The data, one by one
| Source | K₂O | Measured chloride | kg Cl / kg K₂O | pH | Datasheet rate |
|---|---|---|---|---|---|
| BALANCE 6-3-18 | 18 % | 0,941 % | 0,052 | — | 3–4 kg/ha |
| BALANCE 7-7-7 | 7 % | 0,774 % | 0,111 | — | 3–4 kg/ha |
| K-FLOW 20 | 23,21 %(measured) | 3,23 % | 0,139 | 12,52 | 3–6 L/ha |
| PK-FLOW 20 | 19,43 %(measured) | 2,74 % | 0,141 | 7,49 | 2–3 L/ha foliar · 5–10 L/ha fertirrigación |
| FULVEX 50S | 12,00 % | 5,62 % | 0,468 | — | 250–500 g/100 L foliar · 2–6 kg/ha fertirrigación |
| Cloruro potásico (KCl)market reference | 60 % | ~46 % | 0,767 | — | — |
Supply potassium but not yet chloride-tested: BALANCE 3-3-10 · BALANCE 5-5-5
How it is measured and what it does not cover
Chloride was determined by ion chromatography to UNE-EN 10304-1 at an ENAC-accredited laboratory. K₂O comes from each product datasheet; where marked as measured, it is laboratory analysis.
- Provisional results, single batch and single sample.
- The scope is chloride: this dataset covers no other parameter.
- Seven catalogue references have not been tested yet, among them BALANCE 3-3-10 and BALANCE 5-5-5, which also supply potassium.
- The Cl/K₂O ratio is a direct division of the two values above, which do not necessarily come from the same batch.
Frequently asked questions about potassium and chloride
How much chloride does muriate of potash add per unit of potassium?
Roughly 0.770 kg of chloride per kg of K₂O: it runs around 60 % K₂O and 46 % chloride. It is the world's most used and cheapest potassium source, and in chloride-sensitive crops also the most limiting.
Which potassium source adds the least chloride?
Of the measured references in this catalogue, BALANCE 6-3-18 is the lowest: 0.941 % chloride against 18 % K₂O, that is 0.052 kg of chloride per kg of K₂O, about fourteen times less than muriate of potash. Sulphate of potash adds zero, but acidifies and adds sulphur.
Do organic fertilizers contain chloride?
They can. Organic certification attests to the origin of the raw materials and the process, not the chloride content: they are independent. This very catalogue contains certified references with measured chloride as high as 5.62 %, and we publish it.
In which crops does the chloride in potassium fertilizer matter?
Above all in avocado, citrus, blueberry, strawberry and vine, where chloride accumulates at the leaf margin, competes with nitrate for root transporters and raises soil conductivity. In cereal, beet or maize it is rarely limiting.
How is the chloride you publish measured?
By ion chromatography to UNE-EN 10304-1 at an ENAC-accredited laboratory. These are provisional results from a single batch and sample, and seven catalogue references have not been tested yet. We publish which ones.
What pH do the potassium products have?
K-FLOW 20 has pH 12.52 and PK-FLOW 20 pH 7.49. A pH as high as K-FLOW 20's conditions tank loading order and what it can be mixed with; the compatibility tool checks this by product pairs.