I've used both, and without a doubt, in no matter what size tank I've tried both in, aquasoil is superior. But that's just my personal opinion. The AS does leach ammonia and lots of nutrients, especially in the beginning, but you can avoid any algae issues with lots of WCs. Also, the AS buffers the pH considerably lower for me, down to 5.5 from 6.8. That's a nice bonus for plant nutrient uptake. As for ferts, seachem is good but expensive, and I would also suggest dry ferts. Dry ferts are just as good, last for years and are less messy (just need a good set of measuring spoons).