The streambank look is what I wanted to get. It needs to have a wild-natural appearance, rather than the highly manicured, or formal, type presentation. The pebbles do impart a wild aspect.
The KH is where it needs to be so I can hold the pH at a reasonable value (6.
and get at least 30 ppm CO2. This is a high light system and I inject CO2 for robust growth. There is no need to hold down the KH for any particular reason, as the fish are fine with it. Just now the GH is a little higher than normal, as I try to keep it around 110 ppm (6 degrees) also, but there is no harm in the higher value.
I know this looks like a lot of filters, but for a tank this size, the turnover rate is about right. I don't do much by halves!