Sorry for the delay in answering this, but my PC is currently in bits on the floor whilst I put in a new motherboard and processor.
I used Manardo for a short time when I first got my tank a few years back. The guy in the lfs persuaded me to buy it. I was young and innocent, well younger than I am now anyway. I wasn't thrilled with it. Firstly, it's an odd colour... sort of a terracotta red. Secondly, it has an almost neutral buoyancy and so tends to get washed around the tank at the slightest whiff of a current. Thirdly, and this was the killer, it is composed of little round particles that provide very little binding between other particles so you get this sort of slushy red stuff at the bottom of your tank. It's very hard to plant anything in it without the plant floating to the surface the second you turn your back. So I whisked it out and put some sand in.