Straight fertilisers are for growers running their own schedule who want to move one value without dragging the rest along. A ready-made booster always raises several things at once; with these you raise nitrogen alone, phosphorus alone or potassium alone.
The percentage tells you about dosing, not about quality
CANNA carries N 17% Nitrogen, P 17% Phosphorus and K 16% Potassium. Bio G Power carries N 27% Nitrogen and K 20% Potassium. That is nearly a factor of two on nitrogen, and it does not mean one product works harder than the other: it means you need less of it to deliver the same amount of element. So always work back to the element rather than the millilitres, especially when switching brand. Stay on one brand and you simply follow its chart.
EC climbs faster here than you are used to
These are concentrated salts without the buffering of a complete feed. A dose that looks small shifts your EC noticeably, and because you are adding only one element the ratio to everything else moves as well. So measure after mixing with something from Measuring & Control, and only then correct pH with pH Control.
Calcium is why you dose these separately
Nearly every label in this range carries a mixing warning, and they all turn on the same thing: phosphorus, potassium and magnesium must not meet calcium undiluted. So add the components to the water one at a time, stirring in between, and never pour two concentrates straight into each other. The same principle sits behind the two bottles of an A+B feed, and behind the separated calcium and magnesium under CalMag.
Frequently asked questions
When do I need these?
When you have identified a shortage your base feed does not fix, or when you build your own schedule. On a complete line, correcting with a single element is rarely necessary and shifts things faster than you expect.
Can these replace a booster?
Partly. A PK charge from Bloom is phosphorus plus potassium in a worked-out ratio; you can rebuild that from two straights, but then the ratio is your responsibility. For targeted single-element boosts, the Aptus products are under Boosters.
How do I know how much element I am giving?
Multiply the dose by the percentage on the label. That is exactly the sum you skip by going on millilitres alone, and the reason two brands at the same dose can deliver very different amounts.
