Beautiful setup and scape. Interesting that you've laid the aquasoil in the middle and sand along the sides. A nice reversal of the more typical 'sandy path' type scape.
I'm having issues with the CO2 bubble output on my tank too, suspect a dodgy regulator, let us know how the Fabco turns out.
Regarding the window, keep the curtain closed during the peak sunlight hours which would depend on which side of the house your window faces. Swapping curtains for blinds would help, since sunlight can really cause algae issues.
btw. what size transformer are you using with your Grand Solar light?