Just thought I would log that I added a fourth Arcadia freshwater to the tank over the weekend, so that's 4x18w tubes. I have upped it to 9hrs and am running a midday burst method.
3hrs - 2 tubes
3hrs - 4 tubes (3WPG)
3hrs - 2 tubes
I have three ballasts and I guess I could simulate daylight more if I wanted to but not sure yet will see. The wiring in the cabinet is pretty mad already, so don't want to over complicate things if I needn't.
The New plants seem to be doing OK, the Ludwigia (I think it is) has become a lovely reddy brown under the decent light and CO2, which is nice, doubled in size in under a week.
Sam