Anyone used this company before as a top dress product?

[NEGreenery]

Hello guys,

I'm tempted to buy some products from this company. Just confused if they can be used for top-dressing. All of their manuals I've seen describe mixing them in water instead of using it for a top dress.
Here's some of their products in an european store. https://www.growtent.eu/eng_m_Nutrients-substrates_Nutrients_Powder-feeding-2420.html