HarleyK said:Howdy,
I use Eheim Substrat Pro
Surface area 450 sqm/litre (20,000 sqf/gal)
The best thing is: I heard about it at MFK
HarleyK
yes yes yes.... those are cool....
i have rena XP series and all of them use Eheim Substrat Pro ...
if you want cheap bio... go to your local hardware store such as Home Depot and get Lava Rocks!! those works well too!!!