ADA aquasoil do come in smaller 3 liter bags, costs around S$25, works out to cost more per liter though.
Most people just buy the 9 liter bag and keep the excess soil as spares (or split into smaller bags to sell to others).
As for normal type vs powder type, the difference is mainly their soil granule size (and powder type costs more too, around S$70+ for the 9 liter bag).
Here is a soil granule size comparison between the 2 types:
Photo from Google Images.
Powder type aquasoil makes it much easier to plant smaller plants like HC, MC, glosso, hairgrass etc. and the smaller soil granules also help enhance the scale perspective of nano tanks... compared to normal type, which tend to look like "boulders" in small tanks.
Some people use only normal type, while others use only powder type (if they have the budget)... there are also those who use both, ie. bulk of the substrate is normal type, with powder type as the top layer or in areas with smaller plants. So it just depends on your preferences.
Bookmarks