Mendi, honestly speaking, you can get away with just using the Aquasoil. I've grown plants just fine with AS alone. But for a complete line-up of ADA stuff in the order of their usages, here it goes:
1st layer---spread all the powdery stuff(penacW and penacP, Bacter 100, Clear super, Tourmaline BC, etc...)
2nd layer---Power Sand(or if you use Power Sand Special you can skip on Bacter 100 and Clear super as it contains both)
3rd layer---Aquasoil. Depending on the size of your tank as well as personal aesthetics, some will add a layer of Aquasoil Powder just to make everything look finer and smooth out any areas which might look a little jagged or rough.
And there ya have it. Remember you do NOT need nor is it a MUST-have on any of these items, save the Aquasoil. You CAN grow stuff fine just using AS. But using them will only better the results and won't hurt
Good luck and show us your design soon!
BTW, will you use other ADA equipments as well, such as the lighting and filtration stuff like lily pipes?
ADA substrate 
Linear Mode
